EPOS/POSNA Abstract Book (2024)

Table of Contents
WEDNESDAY, MAY 8 SESSION 1–TRAUMA POSNA PRESIDENTIAL SPEAKER SESSION 2—BEST OF SPINE SESSION 3A—ADOLESCENT IDIOPATHIC SCOLIOSIS (AIS) SESSION 3B—FOOT & ANKLE SESSION 3C—NEUROMUSCULAR & CEREBRAL PALSY SESSION 3D—INFECTIONS & TUMORS SESSION 4A—CONGENITAL, SYNDROMIC, & DYSPLASIAS SESSION 4B—HAND & UPPER EXTREMITY SESSION 4C—NEUROMUSCULAR SESSION 4D—SLIPPED CAPITAL FEMORAL EPIPHYSIS THURSDAY, MAY 9 SESSION 5—BAG O’ BONES FRIDAY, MAY 10 SESSION 6—AWARD–NOMINATED PAPERS PART I EPOS PRESIDENTIAL SPEAKER SESSION 7—AWARD–NOMINATED PAPERS PART II SOCIETY AWARD WINNERS SESSION 8A—VERTEBRAL BODY TETHERING (VBT) & SAGITTAL PROFILE SESSION 8B—SPORTS SESSION 8C – LOWER EXTREMITY & DEFORMITY SESSION 8D – DEVELOPMENTAL DYSPLASIA OF THE HIP (DDH) SESSION 9A – EARLY ONSET SCOLIOSIS (EOS) & MISCELLANEOUS SPINE SESSION 9B – ANTERIOR CRUCIATE LIGAMENT (ACL) & MISCELLANEOUS SPORTS SESSION 9C – TRAUMA SESSION 9D – HIP SESSION 10 – PERTHES & MISCELLANEOUS SESSION 11 – TRAUMA BASIC SCIENCE CONGENITAL, SYNDROMIC, AND SKELETAL DYSPLASIAS FOOT & ANKLE HAND/UPPER EXTREMITY HIP INFECTION AND TUMOR LOWER EXTREMITY/DEFORMITY NEUROMUSCULAR QUALITY, SAFETY, VALUE INITIATIVES; ARTIFICIAL INTELLIGENCE; MACHINE LEARNING; AND MISCELLANEOUS SPINE SPORTS TRAUMA OP-1 Radiological, clinical, and functional outcome of children with traumatic hip dislocation: review of 66 cases OP-2 Diaphyseal femur fractures in children under the age of 3—risk factors for non-accidental trauma: a CORTICES multi-center study OP-3 Increased odds of non-accidental traumatic fractures in pediatric patients with intellectual disability disorder: a stratified analysis OP-4 Ischial tuberosity avulsion fractures: treatment and return to sport in athletes with displaced fragments OP-5 Pre-existing femoro-acetabular impingement is associated with pelvic avulsion fractures in adolescents: a matched cohort study OP-6 An emerging healthcare crisis: trends in pediatric firearm injuries over time—analysis of over 1100 cases OP-7 Loss of reduction in pediatric distal radius fractures: risk factors from a prospective multicenter registry OP-8 Modified elastic stable intramedullary nailing, a new approach for distal metaphyso-diaphyseal junction of forearm in children OP-9 Take it or leave it: prevalence and complications from hardware removal following pediatric fracture fixation OP-10 Use of the bioabsorbable Activa IM-Nail™ in pediatric diaphyseal forearm fractures: a prospective cohort study with at least 1-year follow-up* OP-11 Biodegradable magnesium implants—a game changer in pediatric trauma care OP-12 Biodegradable intramedullary nailing of severely displaced distal pediatric metaphyseal radius fractures OP-13 Can scoliosis-specific exercises be performed with wearing brace in treating adolescent idiopathic scoliosis: an alternative use of scoliosis-specific exercises without sacrificing bracing hours OP-14 Surgeon contoured versus pre-contoured patient-specific rods in adolescent idiopathic scoliosis: assessing global sagittal alignment OP-15 Pulmonary function at minimum 10 years after segmental pedicle screw instrumentation for thoracic adolescent idiopathic scoliosis OP-16 Osteotomies at the time of graduation surgery: how much do we get from them? OP-17 Is bracing after completion of Mehta casting worthwhile? OP-18 Limited fusion for congenital scoliosis: is it truly one and done? OP-19 Greater implant density does not improve pelvic obliquity and major curve correction in neuromuscular scoliosis OP-20 The effect of traction and spinal cord morphology on intraoperative neuromonitoring alerts OP-21 What kind of kyphosis? Stratifying thoracolumbar kyphosis in achondroplasia OP-22 Distribution of curve flexibility in idiopathic scoliosis—a descriptive study OP-23 When is growth greatest? Spine and total body growth in idiopathic scoliosis through Sanders maturation stages 2, 3A, 3B, and 4 OP-24 The true cost of late referral in adolescent idiopathic scoliosis: a 5-year follow-up study OP-25 Battle of the braces: a comparison of brace efficacy in patients with adolescent idiopathic scoliosis treated with Providence, Boston-style, and Rigo-Cheneau braces OP-26 Improvement in axial rotation with bracing reduces risk of curve progression in patients with adolescent idiopathic scoliosis OP-27 PROMIS-based assessment of brace compliance OP-28 Can surgery be proposed to adolescent idiopathic scoliosis patients with structural lumbar curves associated with non-reducible iliolumbar angle? OP-29 Utility of routine postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis OP-30 A comparison of opioid-sparing versus opioid-containing postoperative pain management for idiopathic scoliosis OP-31 An accelerated postoperative protocol for discharging posterior spinal fusions home in less than 2 days: comparison of two matched cohorts OP-32 Can surgery improve painful adolescent idiopathic scoliosis patients? OP-33 The postoperative decline in health-related quality of life for adolescents with idiopathic scoliosis undergoing spinal fusion OP-34 The CoCo (Core Outcome ClubfOot) study: recurrence, with poorer clinical and quality of life outcomes, affects 37% of patients—an international multicenter observational study OP-35 Comparison of clinical outcomes, parental anxiety, and surgeon satisfaction during outpatient clinic versus operating room setting for Achilles tenotomy during Ponseti method of clubfoot correction—a randomized controlled trial OP-36 Effect of the abduction bracing on the contralateral foot in patients with unilateral clubfoot deformity: a longitudinal study OP-37 Clubfoot relapse rates in idiopathic clubfoot using the Ponseti method: 65 years of data from a single institution OP-38 Comparative analysis of three anterior tibialis tendon transfer techniques in idiopathic clubfoot OP-39 Rebound of the radiological effect of anterior distal tibia epiphysiodesis in relapsed Ponseti-treated clubfoot patients after implant removal OP-40 Is there a benefit to rigid fixation in calcaneal lengthening osteotomy in painful pediatric idiopathic flatfoot deformity? Comparing results of Kirschner wire versus plate fixation OP-41 Nonunion rate of Evans osteotomy without fixation in pediatric flatfoot OP-42 Improving detection of underlying neurologic etiology for pediatric cavovarus foot deformity: we can do better OP-43 Efficacy of Ponseti casting in arthrogryposis OP-44 Is the proximal lateral epiphysiodesis of the first metatarsal effective in the correction of hallux valgus in the pediatric population? OP-45 The creation and validation of an ankle bone age atlas and data predicting remaining ankle growth OP-46 Hip progression after triradiate cartilage closure in ambulatory cerebral palsy: who needs continued surveillance? OP-47 How well does physical examination predict radiographic hip displacement in children with cerebral palsy? OP-48 Femoral head shaft angle changes based on severity of neurologic impairment in children with cerebral palsy and spinal muscle atrophy OP-49 Proximal femur guided growth for spastic hip displacement in cerebral palsy children—long-term follow-up OP-50 Does the addition of proximal femoral epiphysiodesis in neuromuscular hips improve caput valgum? OP-51 Medialization at the osteotomy site may reduce relapse after varus de-rotational osteotomy (VDRO) of the proximal femur in cerebral palsy OP-52 Combined pelvic osteotomy and proximal femur guided growth for serious hip subluxation in cerebral palsy children OP-53 Medium-term results after femoral head resection and subtrochanteric valgus osteotomy in children and adolescents with cerebral palsy OP-54 The association between hip displacement, scoliosis, and pelvic obliquity in 106 non-ambulatory patients with cerebral palsy: a longitudinal, population-based study OP-55 The evaluation of total hip replacement in management of spastic painful hip dislocation in cerebral palsy OP-56 Inter-rater reliability of a photo-based modified foot posture index (MFPI) in identifying severity of foot deformity in children with cerebral palsy OP-57 Impact of femoral derotation osteotomy and equinus varus foot correction on transverse plane asymmetry in patients with hemiplegic cerebral palsy OP-58 Aspirations dashed: serum neutrophil-to-lymphocyte ratio is not a good predictor of septic arthritis of the hip and knee in pediatric patients OP-59 Severity of osteomyelitis—the bug is the problem OP-60 Featherweight versus heavyweight of pediatric musculoskeletal infections: Kingella versus the titans of Staphylococcus and Streptococcus OP-61 Low prevalence of anaerobic bacteria in pediatric septic arthritis makes obtaining anaerobic cultures of questionable value OP-62 Tiny humans versus a deadly disease: an epidemiologic review of necrotizing fasciitis in pediatric patients OP-63 Awake biopsy in pediatric patients with suspected musculoskeletal malignancy is safe, feasible, cost-effective and reduces time to tissue diagnosis OP-64 Comparison of diaphyseal reconstruction techniques of the lower limbs in childhood malignant tumors: long-term results OP-65 Survivorship of custom-made non-invasive extendable implants in pediatric sarcoma patients OP-66 Sufficiency of isolated vascularized fibula for intercalary reconstruction OP-67 Femoral head cartilage window approach combined with artificial bone implantation for treatment of epiphyseal chondroblastoma in children OP-68 Evidence-based recommendations for treating pediatric desmoid tumors: consensus of the Desmoid Tumor Working Group* OP-69 Retrospective analysis and characterization of avascular necrosis in pediatric leukemia/lymphoma patients using BLAST classification OP-70 Survival of telescoping rods decreases with successive surgeries in patients with osteogenesis imperfecta OP-71 Augmentation of submuscular plates in addition to telescopic rodding in the management of long bone fractures in patients with osteogenesis imperfecta OP-72 Long-term outcomes of intramedullary nails in osteogenesis imperfecta: fewer surgeries and longer survival times with telescoping rods in patients with over 10-year follow-up OP-73 Prophylactic intramedullary rodding following femoral lengthening in patients with achondroplasia and hypochondroplasia OP-74 Spinal surgery in achondroplasia: causes of reoperation and reduction of risks OP-75 Collagen-type 2 skeletal dysplasias: key clinical, radiographic, and MRI findings guide cervical stabilization decision-making OP-76 Screening and early management of hips in children with spina bifida following prenatal surgical closure OP-77 Does open reduction of arthrogrypotic hips cause stiffness? OP-78 Burosomab reduces the need for hemiepiphysiodesis in hypophosphatemic rickets OP-79 Ethnicity is a risk factor for permanent brachial plexus birth injury OP-80 Sprengel deformity: what is the functional outcome and quality of life after surgery according to the EQ-5D-Y and the short version of Disabilites of the Arm, Shoulder, and Hand Questionnaire (quickDASH)? OP-81 Medium- and long-term clinical and functional outcomes of modified Green’s procedure for Sprengel shoulder in children OP-82 Osteot-OH MY! contemporary surgical techniques may reduce revision rates following preaxial polydactyly reconstruction OP-83 Surgical versus nonsurgical management of pediatric ganglia—a cost and outcomes analysis OP-84 Tendon transfer in spastic cerebral palsy upper limb OP-85 Factors influencing return of elbow motion following pinning of displaced supracondylar humeral fractures OP-86 Development of a new classification for forearm involvement in patients with multiple hereditary exostosis (MHE) using the Delphi process OP-87 Flippin’ out over gymnast wrist: presentation and treatment of distal radial physeal stress syndrome in young gymnasts OP-88 Cerebral palsy in the British Orthopedic Surgery Surveillance Study (CPinBOSS) OP-89 Health-related quality of life in ambulatory children with physical disabilities OP-90 What is the prevalence of depressive symptoms and antidepressant use among adult patients with cerebral palsy? OP-91 Accuracy and reliability of mobile app–enhanced observational gait analysis in children with cerebral palsy OP-92 The risk factors associated with increased anterior pelvic tilt in ambulatory children with cerebral palsy OP-93 The association between increase in knee range of motion and patient satisfaction after rectus femoris transfer in cerebral palsy OP-94 Is the CPCHILD questionnaire responsive—assessing HRQoL changes and performance of the CPCHILD after hip and spine surgery in children with severe cerebral palsy OP-95 Disease-modifying therapy changed the natural course of spinal muscular atrophy type 1: what about spine and hip? OP-96 Increased knee range of motion in patients with arthrogryposis: minimum 2-year follow-up OP-97 Obesity-related alterations in capital femoral epiphysis morphology: an extensive analysis of 8717 hips utilizing automated 3D-CT imaging OP-98 Intraoperative perfusion monitoring does not reliably predict osteonecrosis following treatment of unstable SCFE OP-99 Bone scintigraphy can predict post-operative femoral head avascular necrosis in children with hip trauma and slipped capital femoral epiphysis OP-100 Epiphyseal stability increases specificity of the Loder classification system in prognosticating AVN after slipped capital femoral epiphysis OP-101 Rate and risk factors for contralateral slippage in adolescents treated for slipped capital femoral epiphysis: a comprehensive analysis of 3528 cases OP-102 Temporary in situ pinning with subsequent modified Dunn is a safe alternative to primary modified Dunn OP-103 Risk factors of vitamin D deficiencies on SCFE development OP-104 Intertrochanteric Imhauser’s osteotomy combined with osteochondroplasty in management of slipped capital femoral epiphysis OP-105 Long-term outcomes for total joint arthroplasties in pediatric and young adult populations OP-106 Universal ultrasound screening for DDH may be cost effective: a Markov decision analysis model incorporating the entire lifespan OP-107 Deep-learning algorithm accurately measures migration percentage on hip surveillance radiographs OP-108 Suprainguinal fascia iliaca nerve blocks outperform epidural analgesia in patients undergoing periacetabular osteotomy OP-109 Virtual children’s fracture clinic—a prospective study of 5536 patients confirming that efficiency and cost saving does not compromise safety OP-110 Prevalence of osteochondromas in the spine in patients with multiple hereditary exostoses OP-111 Predictors of complication in pediatric hardware removal OP-112 Significant improvement in health-related quality of life following surgical treatment of congenital muscular torticollis among a 2-year follow-up cohort of children, adolescents, and young adults OP-113 The hidden consequences of advanced operative spine imaging in children: do the suggested benefits of intraoperative computed tomography and navigation in posterior spinal fusion for adolescent idiopathic scoliosis outweigh the possible lifetime oncological risks of increased radiation exposure? OP-114 Radiation shielding during bedside fluoroscopy reduces radiation exposure to pediatric patients OP-115 Suicidal ideation in pediatric orthopedic patients OP-116 From bytes to bones: assessing the ability of ChatGPT to educate patients and families in pediatric orthopedic surgery OP-117 Greater obstetric barriers for female orthopedic surgeons compared to the general population and peer physicians OP-118 Full-thickness skin graft versus hyaluronic acid skin graft substitute in syndactyly release: a randomized trial OP-119 Outcomes following operative versus non-operative treatment of completely displaced midshaft clavicle fractures in adolescent baseball players and other overhead athletes OP-120 Two-year patient-reported outcomes and graft rupture following ACL reconstruction in skeletally immature athletes: results from the PLUTO (pediatric ACL: understanding treatment options) prospective cohort study OP-121 Fabrication of a biomimetic 3D-printed scaffold for the treatment of large osteochondral defects in an adolescent porcine model: outcomes at 6 months OP-122 Long-term outcome of nonoperative treatment of Perthes disease—244 hips with a mean follow-up of 48 years OP-123 In situ fixation of slipped capital femoral epiphysis carries an over 40% risk for later total hip replacement during a long-term follow-up OP-124 Mid-term outcomes following vertebral body tethering: a single-center cohort with 5+ years of follow-up OP-125 A CNP analog as adjuvant treatment for moderate-to-severe osteogenesis imperfecta in the growing mouse: a pilot study OP-126 Bi-lateral and bi-level erector spinae plane block in pediatric idiopathic scoliosis surgery: a randomized, double-blind, controlled trial OP-127 Local wound infiltration reduces acute postoperative opioid requirements in AIS: a prospective double-blind randomized controlled trial OP-128 Efficacy of a multimodal surgical site injection in pediatric patients with cerebral palsy undergoing hip reconstruction: a randomized controlled trial OP-129 Analysis of regenerate bone formation using internal lengthening nails in a large animal model: a pilot study OP-130 Long-term results of epiphyseal distraction prior to resection (Cañadell’s technique) in 169 patients with metaphyseal pediatric bone sarcomas OP-131 Use of serum biomarkers and cytokines to differentiate septic arthritis, osteomyelitis, and transient synovitis in pediatric and adolescent patients OP-132 Kicking the can in DDH: the impact of age on outcomes following secondary reconstructive surgery for residual dysplasia OP-133 Late-diagnosed DDH is rare in Finland with universal clinical screening program complemented with selective ultrasonography OP-134 Navigation versus fluoroscopy for anterior VBT screw placement, analysis of 530 screws with confirmatory 3D imaging OP-135 Growth modulation response in thoracic VBT depends primarily on magnitude of concave vertebral body growth OP-136 Spontaneous correction of the thoracic curve in Lenke 5 patients: lumbar vertebral body tether (VBT) versus posterior fusion OP-137 Are outcomes improving for AIS following FDA HDE approval? OP-138 Outcomes in patients with tether rupture after anterior vertebral tethering (AVT) for adolescent idiopathic scoliosis: the good, the bad, and the ugly OP-139 Complications in vertebral body tethering: what are the effects on patient-reported outcomes? OP-140 Implementation of the Team Integrated Enhanced Recovery (TIGER) protocol following vertebral body tethering OP-141 Validation study of MR bone-like image for diagnosis of stress fracture (spondylolysis) in the lumbar spine OP-142 Treatment and health-related quality of life of acute adolescent spondylolysis: a prospective comparative study with 2-year follow-up OP-143 Spondylolysis, spondylolisthesis, and associated variables in pediatric patients with osteogenesis imperfecta: follow-up from a 2011 study OP-144 Is it necessary to extend fusion to L4 when correcting pediatric L5/S1 spondylolisthesis? OP-145 Spinal fusion for Scheuermann kyphosis has higher complication and revision rates than spinal fusion for idiopathic scoliosis OP-146 Arthroscopic Bankart repair for anterior glenohumeral instability in 488 adolescents between 2000 and 2020: risk factors for subsequent revision stabilization OP-147 Length of post-treatment immobilization following medial humeral epicondyle avulsion fracture and return of full range of motion: an interim analysis OP-148 Mid-term results of treatment of traumatic knee chondral fractures in adolescents OP-149 Patellar lateralization, absence of hyperlaxity, and the mechanism of injury are associated with osteochondral fracture after first-time acute lateral patellar dislocation in adolescents: an MRI-based evaluation OP-150 Number of patellar dislocation events is associated with increased chondral damage of the trochlea: data from the JUPITER group OP-151 Dysplasia worsens over time: trochlear morphologic changes in skeletally immature patients across consecutive magnetic resonance imaging studies OP-152 The incidence and risk factors for an osteochondral fracture after patellar dislocation OP-153 Isolated medial patellofemoral ligament reconstruction with and without bony patellar fixation in young patients: a multicenter comparison of three operative techniques OP-154 Higher rate of redislocation and osteoarthritis after proximal realignment procedures vs MPFL reconstruction: a comparative long-term study of patellar instability in adolescents with open physis with mean 9 years of follow-up OP-155 Suture-based repair with debridement and bone grafting of unstable osteochondritis dissecans of the knee OP-156 Osteochondritis dissecans of the femoral condyle and coronal malalignment: an evaluation of the demographics, incidence, and severity of disease OP-157 Osteochondral allograft transplantation for capitellar osteochondritis dissecans: excellent patient-reported outcome scores and high return to sports OP-158 Intraarticular deformity after temporary epiphysiodesis around the knee OP-159 Removal of the metaphyseal screw from tension band constructs after angular correction with hemiepiphysiodesis has high rates of physeal tethering and subsequent need for implant removal OP-160 Accuracy of four different methods for estimation of remaining growth and timing of epiphysiodesis OP-161 Does osteotomy level influence consolidation time in tibias treated for limb length discrepancy? OP-162 Does perioperative ketorolac affect bone healing in pediatric limb lengthening or reconstruction patients? OP-163 Evaluation of physical and mental health in adults who underwent limb-lengthening procedures with circular external fixators during childhood or adolescence OP-164 Infection rates and risk factors with magnetic intramedullary lengthening nails OP-165 Are you ready to rumble? Fitbone versus precise nail smackdown for managing limb length discrepancy OP-166 Chronic knee pain following infrapatellar/suprapatellar magnetic intramedullary lengthening nails versus external fixators in limb length discrepancy OP-167 Three-dimensional gait analysis and patient-reported outcome measures before and 1 year after femoral derotational osteotomy in adolescents with increased femoral anteversion OP-168 Correlation of preoperative simultaneous fibular pseudarthrosis with postoperative ankle valgus risk in congenital tibia pseudarthrosis patients OP-169 Will my child walk funny? The rotational profile of infants and children with classic bladder exstrophy OP-170 Development and validation of a diagnostic aid for developmental dysplasia of the hip OP-171 Spontaneous recovery in the vast majority of stable dysplastic hips OP-172 Follow-up after successful Pavlik Harness treatment for DDH: is 2 years enough? OP-173 Comparable amount of residual dysplasia after active surveillance versus abduction brace treatment OP-174 Influence of standardized hip ultrasound protocol in Pavlik harness during management of developmental hip dislocation OP-175 Utility of “Pavlik holiday” for infantile hip dysplasia following failure of Pavlik harness treatment OP-176 Predicting the resolution of residual acetabular dysplasia following successful brace treatment for developmental dysplasia of the hip in infants OP-177 Residual acetabular dysplasia at walking age: a study of 470 hips treated with Pavlik harness OP-178 Salter innominate osteotomy for the treatment of developmental dysplasia of the hip in children: Results of 99 consecutive osteotomies after 13–34 years of follow-up OP-179 Outcomes following closed reduction for developmental dislocation of the hip OP-180 Closed reduction in developmental dysplasia of hip: predicting acetabular remodeling at skeletal maturity OP-181 Acetabular remodeling in developmental dysplasia of the hip: a tri-center analysis of open versus closed reduction in 459 hips OP-182 Reevaluating the role of triradiate cartilage status in shaping curve progression among patients with juvenile idiopathic scoliosis OP-183 Increased thoracic sagittal spine length improves pulmonary function in early-onset scoliosis OP-184 Documenting the variation of proximal foundation constructs and their correlation with unplanned return to the operating room in children with magnetically controlled growing rods OP-185 More screws, more OR time, same failure rates: enabling technology use in proximal fixation of growing spine constructs OP-186 The risks and benefits of definitive surgery in the graduation of i-EOS patients whose deformities were managed with GR: a comparison with matched AIS patients OP-187 Lessons learned from 20 years of history using Vertical Expandable Prosthetic Titanium Rib (VEPTR) in early-onset scoliosis patients OP-188 Quality of life assessment in early-onset scoliosis: a comparison between the EOSQ-24 and EOSQ-SELF questionnaires on the same patients with two different respondents and time points OP-189 Utility of preoperative echocardiogram for large curve scoliosis patients OP-190 Intraoperative CT-based technology significantly increases radiation exposure in the pediatric population OP-191 In the era of liposomal bupivacaine: is patient-controlled analgesia even needed? OP-192 Safety data for robotics coupled with navigation for pediatric spine surgery: initial intraoperative results of a prospective multicenter POSNA-funded registry OP-193 The impact of lumbar microdiscectomy in adolescents on PROMIS pain, physical function, and mental health domains OP-194 What are the morphological risk factors for pediatric anterior cruciate ligament tears and tibial spine fractures? OP-195 Dynamic point-of-care ultrasound is effective in the early diagnosis of anterior cruciate ligament injuries in children and adolescents OP-196 Low rates of complications following quadriceps tendon autograft ACL reconstruction in adolescents: strategies for success in the first 12 months OP-197 Addition of a lateral extra-articular procedure to ACL reconstruction does not increase early complications in pediatric patients OP-198 Risk factors associated with stiffness following pediatric ACL reconstruction: a multicenter study OP-199 Septic arthritis after anterior cruciate ligament reconstruction in pediatric and adolescent vs young adult patients: the 20-year experience at a regional referral center OP-200 Do children differ from adults in functional limb testing measured at 9 months after ACL reconstruction? OP-201 Features of discoid lateral meniscus in pediatric patients with achondroplasia OP-202 MRI-guided retrograde joint-sparing drilling of osteochondritis dissecans of the talus in children OP-203 Is it worth a shot? Efficacy of a multimodal pain program for pediatric and adolescent knee procedures with and without a single-shot peripheral nerve block OP-204 To block or not to block? Results from the Society of Pediatric Anesthesia Improvement Network OP-205 Single-shot peripheral nerve blocks with Precedex increase neurotoxic complications in pediatric and adolescent arthroscopic knee procedures* OP-206 Subaxial cervical spine injury classification system (SLIC) score is useful in guiding treatment decisions in pediatric cervical spine trauma OP-207 Ring the alarm: pediatric patients with operative pelvic ring injuries have similar mortality and morbidity to adults in a national matched cohort study OP-208 Etiology and mortality of acute pediatric compartment syndrome: a retrospective review OP-209 The experience of adolescent females following completely displaced midshaft clavicle fractures: sex-specific differences in pain, sensory symptoms, and activities of daily life following surgical treatment OP-210 Presence of dorsal spike fragment in conjunction with pediatric volar Barton fracture conveys high risk of delayed extensor tendon injury OP-211 Physeal fractures of the distal ulna: incidence and risk factors for premature growth arrest OP-212 “Don’t fear the reamer”: 20-year trends of pediatric femoral fracture fixation show increased utilization of rigid nails in ABOS part II candidates OP-213 How fast and how far? Prospective study on femoral overgrowth in diaphyseal femur fractures OP-214 Factors associated with premature physeal closure after distal femur fracture OP-215 Do patient-answered versus parent-answered patient-reported outcomes differ in pediatric fracture care? OP-216 Validation of the patient-/parent-reported outcome measure of fracture healing (PROOF-LE) questionnaire for lower extremity fractures in children OP-217 Home management of pediatric buckle fractures: can video education replace an in-person visit? OP-218 I thought things were too loose? Prevalence and risk factors for stiffness following open reduction for developmental dysplasia of the hip OP-219 Open reduction of hip dislocations in arthrogryposis is associated with higher rates of AVN than idiopathic DDH: a dual-center study OP-220 Developmental hip dysplasia: what happens after Pavlik? OP-221 The effect of femoral deformity on hip contact mechanics in patients with hip dysplasia: a finite element analysis study OP-222 Prevalence and radiographic measurements of acetabular dysplasia in over 4000 healthy Dutch adolescents OP-223 A biomechanical analysis of the surface contact pressure after an innominate osteotomy for the correction of acetabular dysplasia OP-224 Does femoral version impact the patient-reported outcomes and clinical meaningful improvement after periacetabular osteotomy for the treatment of acetabular dysplasia? OP-225 Differences in femoro-acetabular impingement morphology on CT between adolescent males and females with symptomatic FAI OP-226 A detailed 3D analysis of hip center of rotation trajectory and its effects on impingement-free range of motion: a 3D dynamic analysis of 1222 hips OP-227 Patient-reported outcomes of femoro-acetabular impingement in adolescents with open physes and duration of symptoms: a match-paired analysis OP-228 Expectations before periacetabular osteotomy and relation to postoperative outcomes and satisfaction OP-229 Intraoperative neuromonitoring during periacetabular osteotomy provides actionable alerts: why is it not more widely used? OP-230 MRI perfusion correlates with duration of stages and lateral pillar class in Legg-Calvé-Perthes disease OP-231 Early-stage femoral head hypoperfusion correlates with femoral head deformity at intermediate-term follow-up in patients with Legg-Calvé-Perthes disease OP-232 Legg-Calve-Perthes disease: to operate or not to operate! OP-233 Correlation between radiological parameters and PROMs results in 141 adults who suffered a Perthes disease in childhood: should we modify our approach in the phase of sequelae? OP-234 Predictors of persistent limp following proximal femoral varus osteotomy for Perthes disease OP-235 Comparison of mid- to long-term outcomes of conservative treatment versus shelf acetabuloplasty in Perthes disease OP-236 Improved gait and patient-reported outcomes following hip preservation procedures via surgical hip dislocation in adolescents with residual Legg-Calve-Perthes disease OP-237 Development of a minimally invasive piglet model of Legg-Calve-Perthes disease OP-238 Two novel tissue types identified in 3D morphometric analyses of Perthes hips: is this the key to early prognostic modeling? OP-239 Vitamin D—a risk factor for bone fractures in children: a population-based prospective case–control randomized cross-sectional study OP-240 Time to closed reduction in the ED: who is at risk for delays, and does it matter? OP-241 Nonoperative vs operative management of type I pediatric open fractures OP-242 Gartland type IIB supracondylar fractures can be treated using Blount’s method OP-243 Does time to surgery impact nerve recovery in supracondylar humerus fractures with nerve injury? OP-244 Epidemiology of operatively treated pediatric medial epicondyle fractures OP-245 Enhancing tibial spine fracture repair: suture plus diaphyseal suture anchors biomechanically outperform sutures and screws in pediatric cadaveric knees OP-246 Risk factors for combined tibial tubercle avulsion fracture and patellar tendon tears OP-247 Risk factors for the development of premature physeal closure after a McFarland fracture in children OP-248 Prospective distal tibial physeal fractures: short leg vs long leg casting OP-249 Remodeling potential after distal tibial physeal fractures OP-250 Identification of and response to growth arrest following pediatric ankle fractures e-Poster 1 Alterations in the bone collagen organization in osteogenesis imperfecta e-Poster 2 Changes around knee after apophysiodesis of tibial apophysis in rats (preliminary results) e-Poster 3 Circ_0000888 regulates osteogenic differentiation of periosteal mesenchymal stem cells in congenital pseudarthrosis of the tibia e-Poster 4 Guided growth for trochlear dysplasia: development of a rabbit model e-Poster 5 Hip dysplasia in mucopolysaccharidosis type 1 Hurler: midterm radiological and functional outcomes after hematopoietic stem cell-gene therapy e-Poster 6 Quantitative MRI may help detect bone repair in a piglet model of Legg-Calvé-Perthes disease e-Poster 7 Sulfur biology may be key to the etiology of developmental dysplasia of the hip e-Poster 8 Characterization of bone growth patterns across the lifespan of individuals with osteogenesis imperfecta e-Poster 9 Therapeutic effect of intramedullary reaming and nailing for long bones lengthening in children with Ollier disease and Maffucci syndrome on enchondromas: retrospective series e-Poster 10 To stand or not to stand: a retrospective review of clinical and health-related quality of life outcomes related to supported standing in patients with MMFC1 spina bifida e-Poster 11 Does clubfoot affect sports performance? e-Poster 12 Pedobarography and ankle-foot kinematics in children with symptomatic flexible flatfoot after medializing calcaneal osteotomy: a cross-sectional study e-Poster 13 Sports participation reported in children and adolescents after treatment for idiopathic clubfoot using Ponseti method e-Poster 14 Surgical considerations for children with foot syndactyly e-Poster 15 Clinical presentation and patient-reported function in children with Sprengel’s deformity e-Poster 16 Lengthening over the plate in forearm deformity: a novel technique to reduce the duration of external fixation and related complications e-Poster 17 Pediatric radial head ossification patterns e-Poster 18 Reachable workspace by injury level in brachial plexus birth injury e-Poster 19 Recreational-therapeutic workshops for the use of myoelectric prostheses in upper-limb agenesis e-Poster 20 Throwing pains: clinical presentation and surgical outcomes of cubital tunnel syndrome in children and adolescents e-Poster 21 A hybrid virtual baby hip clinic improves care for the nonoperative treatment of developmental dysplasia of the hip e-Poster 22 A novel low-cost acoustic screening method for early detection of developmental dysplasia of the hip in infants e-Poster 23 Acetabular changes in 80 surgically treated Perthes patients, from diagnosis to healing e-Poster 24 (Nominated for Best e-Poster) Acetabular teardrop ratio, a novel radiographic measurement in developmental dysplasia of the hip e-Poster 25 Anteroinferior iliac spine osteoplasty at the time of periacetabular osteotomy helps preserve preoperative range of motion e-Poster 26 Birthweight correlates to pubo-femoral distances and alpha angles in hip ultrasound of newborns at 6 weeks of age e-Poster 27 Combined guided growth and growth tethering versus varus osteotomy for caput valgum and leg length discrepancy following surgery in developmental dysplasia of the hip: outcome of the hip development e-Poster 28 Femoral anteversion assessment: 3D modelization insight e-Poster 29 How long is a piece of string? Duration of Pavlik harness treatment for developmental dysplasia of the hip e-Poster 30 Impact of Pavlik harness treatment on motor skills acquisition: a prospective study e-Poster 31 Withdrawn e-Poster 32 Natural evolution of Legg-Calvé-Perthes disease in children “surgical hips” treated with a nonoperative approach e-Poster 33 One-third of patients with slipped capital femoral epiphysis have abnormal thyroid screening studies e-Poster 34 (Nominated for Best e-Poster) Optimizing the arthrogram: does local anesthetic improve the duration of femoral head visualization? e-Poster 35 Osteochondral allograft transplantation for large chondral lesions of the femoral head in young patients e-Poster 36 Outcomes of hip arthroscopy with concomitant periacetabular osteotomy: minimum 5-year follow-up e-Poster 37 Outcomes of treatment of pediatric pathologic femoral neck fractures e-Poster 38 Patients with CMT undergoing a Bernese PAO return to baseline gait parameters and improve patient-reported outcomes at 2 years but are worse than normal controls e-Poster 39 Perthes disease. Ellipsoidal process: is it possible to prevent the deformity? e-Poster 40 Postoperative cast immobilization might be unnecessary after pelvic osteotomy for children with developmental dysplasia of the hip: a systematic review e-Poster 41 Preoperative gallows traction as an adjunct to hip open reduction surgery: is it safe and is it effective? e-Poster 42 Radiation burden and associated cancer risk among children undergoing open reduction for developmental dysplasia of the hip e-Poster 43 Re-analyses of treatment outcomes and prognostic factors of a large prospective multicenter study of Legg-Calvé-Perthes disease using the sphericity deviation score e-Poster 44 (Nominated for Best e-Poster) Relationship of self-reported pain, degree of hip dysplasia, and behavioral health diagnosis in adolescents and young adults e-Poster 45 Shenton’s line in DDH: useful or useless? e-Poster 46 The anterior modified San Diego acetabuloplasty does not result in improved anterior acetabular coverage e-Poster 47 The detrimental effect of human growth hormone treatment on the development of slipped capital femoral epiphysis e-Poster 48 The sphericity deviation score, a continuous parameter to assess femoral head sphericity in Legg-Calvé-Perthes disease: is it useful and reliable? e-Poster 49 Trans-perineal hip ultrasound in Developmental Dysplasia of the Hip patients treated with Pavlik harness and Tübingen hip flexion splint e-Poster 50 Treatment outcomes at skeletal maturity after physeal-sparing procedure for early-onset slipped capital femoral epiphysis e-Poster 51 Ultrasound and magnetic resonance in spica cast for detection of femoral head reduction in unstable developmental dysplasia of the hip e-Poster 52 Upper retinacular vascular avulsion: a newly described cause of avascularity of the femoral epiphysis in unstable slipped capital femoral epiphysis e-Poster 53 Clavicular osteomyelitis in children: special considerations for the orthopedic surgeon e-Poster 54 (Nominated for Best e-Poster) Does rickets carry an increased risk of osteomyelitis and septic arthritis? a large database study e-Poster 55 Is exclusive oral antibiotic treatment feasible in pediatric uncomplicated osteomyelitis? e-Poster 56 It is as easy as complete blood cell (with a Diff): using the neutrophil-to-lymphocyte-to-platelet ratio to determine the severity of pediatric musculoskeletal infection e-Poster 57 Knee septic arthritis or Lyme disease: can it be predicted? e-Poster 58 Neurodivergent patients are at increased risk of infection after orthopedic surgery: a multicenter cohort study across 25 years e-Poster 59 Pathologic fractures in patients with neuroblastoma impacts overall survival e-Poster 60 Peroneal nerve decompression in pediatric patients with multiple hereditary exostoses e-Poster 61 Withdrawn e-Poster 62 Resident-performed bedside aspiration for workup of the pediatric septic hip: expedited diagnosis, no decrease in time to definitive treatment e-Poster 63 (Nominated for Best e-Poster) Separate resection of biopsy tract and primary sarcoma: implications for local recurrence and overall survival e-Poster 64 Single-stage surgical debridement with and without local application of vancomycin-loaded calcium sulfate for treatment of chronic osteomyelitis in children: a comparative study e-Poster 65 Treatment of aneurysmal bone cysts in children and risk factors for fractures and complications: a multicenter study e-Poster 66 Withdrawn e-Poster 67 A novel plate design for rotational guided growth: an experimental study in immature porcine femurs e-Poster 68 (Nominated for Best e-Poster) Assessing the accuracy of predictive models in angular deformity e-Poster 69 Comparing relative value units for intramedullary limb lengthening procedures to common pediatric orthopedic surgeries to determine adequate compensation e-Poster 70 Decision-making in congenital femoral deficiency: a stated preference survey of patients, parents, and clinicians e-Poster 71 Does percentage of canal reaming prior to insertion of motorized intramedullary nails influence consolidation time in limb length discrepancy corrections? e-Poster 72 Hemi-epiphysiodesis correction rates for lower extremity malalignment are similar between multiple hereditary exostoses and idiopathic populations e-Poster 73 (Nominated for Best e-Poster) Infantile Blount disease and overweight in Ghana e-Poster 74 (Nominated for Best e-Poster) International field test of LIMB-Q Kids: a new patient-reported outcome measure for lower limb differences e-Poster 75 Limb reconstruction in severe tibial hemimelia: minimum 4-year follow-up e-Poster 76 Magnetic intramedullary lengthening nails can be lengthened to their maximum with no increase in nail failure e-Poster 77 Patients with lower limb deficiencies mobilizing with extension-prosthesis: long-term follow-up, quality of life, and function e-Poster 78 Re-use of motorized intramedullary limb lengthening nails* e-Poster 79 Unrecognized consequences of growth modulation: are we prioritizing limb alignment over future joint health? e-Poster 80 Withdrawn e-Poster 81 Clinical, densitometric, and laboratory evaluation of bones in children with neuro-orthopedic diseases resulting in motor disability e-Poster 82 (Nominated for Best e-Poster) Incidence of femur fracture post hardware removal in children with cerebral palsy who have undergone varus derotational osteotomy e-Poster 83 Medium-term outcomes after multi-level surgery in children with bilateral cerebral palsy e-Poster 84 One injection of Botulinum toxin A in biceps brachii in cerebral palsy has both a degenerative and regenerative effect e-Poster 85 Recurrence of spastic planovalgus foot in cerebral palsy: a comprehensive study on influencing factors e-Poster 86 Rotation and asymmetry of the axial plane pelvis in cerebral palsy: a computed tomography–based study e-Poster 87 Talo-calcaneal-navicular realignment surgery in severe neurologic equinovarus foot: mid-term results of a novel surgical approach e-Poster 88 Worsening gait deviations in hereditary spastic paraparesis e-Poster 89 Cost-analysis and variability in pediatric anterior cruciate ligament reconstruction: insights for optimizing surgical value e-Poster 90 Efficacy of DIY cast covers: an in vivo study e-Poster 91 Embracing wide awake techniques in pediatric orthopedic surgery e-Poster 92 Late diagnosis of developmental dysplasia of the hip in a country using selective ultrasound screening e-Poster 93 Long-term complications of peripheral nerve blocks in pediatric orthopedic lower extremity procedures: a systematic review e-Poster 94 (Nominated for Best e-Poster) Optimizing intraoperative irradiation levels for pediatric orthopedics surgeries: radiation doses does matter e-Poster 95 POSNA Safe Surgery Program: first-year results for entire POSNA membership e-Poster 96 Safety profile following tibial tubercle osteotomy for adolescents in an ambulatory surgery center e-Poster 97 The importance of surgeon dashboarding for comparative quality and safety outcomes when adopting robotics in practice e-Poster 98 (Nominated for Best e-Poster) Utilizing neural networks for ultrasound evaluation of developmental dysplasia of the hip e-Poster 99 Two-year follow-up from a prospective study on a posterior dynamic distraction device for adolescent idiopathic scoliosis e-Poster 100 A comparison of intrathecal morphine injection versus intravenous methadone for pain control for posterior spinal fusion in adolescent idiopathic scoliosis e-Poster 101 A Comparison of two central sacral vertical line methods and their effect on curve correction e-Poster 102 Accuracy and safety of 3D-printed patient-specific pedicle screw insertion technique in complex spine deformity correction: analysis of 60 patients performed at a large academic center e-Poster 103 An efficient, steady, or dual-surgeon allows for the best outcomes? e-Poster 104 Analysis of 5525 consecutive pedicle screws placed utilizing robotically assisted surgical navigation: surgical safety and early complications e-Poster 105 Comparison of perioperative complication rates in congenital scoliosis patients with tethered cord e-Poster 106 Complexities of orthopedic epidemic: adolescent back pain e-Poster 107 Development of pelvic incidence, sacral slope, and pelvic tilt and the effect of age, sex, and body mass index: an automated 3D-computed tomography study of 10,969 children and adolescents e-Poster 108 (Nominated for Best e-Poster) Differences in spine growth potential for sanders maturation stages 7A and 7B have implications for treatment of idiopathic scoliosis e-Poster 109 Do neuromuscular early-onset scoliosis patients with rib-on-pelvis deformity have decreased reported pain after surgery? e-Poster 110 Do parents and patients with early-onset scoliosis share the same perspective on health-related quality of life? A comparison of EOSQ-24 and SRS-22 scores e-Poster 111 (Nominated for Best e-Poster) Early tether rupture prior to 2 years compromises growth modulation by failing to impede convex growth e-Poster 112 Effectiveness of a subcutaneous bupivacaine catheter for pain control and opioid reduction in pediatric spine fusion surgery: a retrospective cohort study e-Poster 113 (Nominated for Best e-Poster) Have we improved anterior vertebral body tethering outcomes over time? an examination of survivorship trends e-Poster 114 Hip pain after spinopelvic fixation with sacral alar iliac screws in pediatric neuromuscular scoliosis e-Poster 115 Impact of comorbidities on mortality in neuromuscular patients with early-onset scoliosis e-Poster 116 (Nominated for Best e-Poster) Intraoperative neuromonitoring events during spinal fusion for scoliosis: a case series e-Poster 117 (Nominated for Best e-Poster) Is a BrAIST for one, a BrAIST for all? evaluating the effect of the BrAIST trial on spinal fusion rates across race and insurance status e-Poster 118 Lowest instrumented vertebra selection in thoracic adolescent idiopathic scoliosis: lowest instrumented vertebra selection drawn for Cotrel–Dubousset original technique including sagittal disk mobility e-Poster 119 (Nominated for Best e-Poster) Lowest instrumented vertebra in treatment of adolescent idiopathic scoliosis is not correlated with PROMIS scores e-Poster 120 Medical issues complicate 90-day return to the emergency department following spinal deformity surgery e-Poster 121 (Nominated for Best e-Poster) Magnetic resonance imaging results in patients undergoing surgery for adolescent idiopathic scoliosis: neural axis abnormalities and neurosurgical interventions e-Poster 122 Multi-disciplinary perioperative pathway for neuromuscular scoliosis patients e-Poster 123 Novel surface topographic assessment of lung volume in pediatric spinal deformity patients e-Poster 124 Pelvic asymmetry in myelomeningocele associated with scoliosis e-Poster 125 Peri-operative outcomes of posterior dynamic deformity device compared to vertebral body tethering for adolescent idiopathic scoliosis e-Poster 126 Plastic multilayered closure reduces surgical site infections in pediatric neuromuscular scoliosis surgery e-Poster 127 PROMIS and ODI tools: clinically useful predictors of abnormal magnetic resonance imagings in pediatric back pain? e-Poster 128 Put a ring on it! wedding band connectors have fewer complications than tandem connectors in traditional growing rod constructs e-Poster 129 Withdrawn e-Poster 130 Rigo Cheneau brace for adolescent idiopathic scoliosis: higher in brace correction and lower rates of curve progression e-Poster 131 Rigo versus Boston brace for the treatment of adolescent idiopathic scoliosis e-Poster 132 Risk of proximal junctional kyphosis after revision of growing rod constructs e-Poster 133 Safety and efficacy of a novel technique for posterior column osteotomy in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion e-Poster 134 Screening magnetic resonance imaging in congenital early-onset scoliosis: is it safe to delay advanced imaging to decrease early anesthesia? e-Poster 135 Similar results with less spinal cord exposure: comparison of in situ osteotomies with traditional Ponte osteotomies in adolescent idiopathic scoliosis e-Poster 136 The fate of the broken tether: how do curves treated with vertebral body tethering behave after tether breakage? e-Poster 137 The impact of operating room process versus team standardization on outcomes in pediatric spinal deformity surgery e-Poster 138 Thoracic deformity index correlates with poorer pre-operative pulmonary function testing in patients with adolescent idiopathic scoliosis of the thoracic spine e-Poster 139 Vertebral body tethering versus posterior spinal fusion for Lenke 1 adolescent idiopathic scoliosis: a single surgeon comparison with 2- to 6-year follow-up e-Poster 140 What factors impact flexibility after spinal fusion? e-Poster 141 A cadaveric study of the sagittal patellar insertion of the medial patellofemoral ligament in children: implications for reconstruction e-Poster 142 Biomechanical comparison of four “hashtag” suture patterns for repair of lateral meniscus radial tears e-Poster 143 (Nominated for Best e-Poster) Different roads traveled: disparities in the preoperative timeline result in delays to pediatric anterior cruciate ligament reconstruction e-Poster 144 Discoid meniscus with anterior instability: incidence, presentation, diagnosis, treatment, and outcomes e-Poster 145 Factors associated with return to sports in patients undergoing anterior cruciate ligament surgery: a 20-year analysis at a tertiary-care children’s hospital e-Poster 146 Hamstring autograft is associated with increased knee valgus moment after anterior cruciate ligament reconstruction: a biomechanical analysis of autograft selection after anterior cruciate ligament reconstruction e-Poster 147 High frequency of meniscal injuries found in adolescents with anterior cruciate ligament tears e-Poster 148 Osteochondritis dissecans of the talus: composite cancellous bone and morselized allograft cartilage grafting results in excellent patient-reported outcomes and return to play e-Poster 149 Predictive characteristics of meniscal tear locations with concomitant anterior cruciate ligament injury in adolescents e-Poster 150 Rates of reoperation and readmission following arthroscopic pediatric and adolescent knee surgery: data from the SCORE patient registry, 2018–2022 e-Poster 151 Surgical management and long-term follow-up of congenital and obligatory patellar dislocation in children e-Poster 152 Your patella dislocated: will it happen again? an assessment of magnetic resonance imaging criteria for recurrent patella dislocation after an initial event e-Poster 153 “Heat mapping” of pediatric and adolescent gun violence in an urban center: is targeted intervention one possible solution? e-Poster 154 A clinical and scientific paradigm shift: revisiting growth after pediatric radius fracture plating e-Poster 155 A prospective cohort analysis of two nonoperative treatment modalities for the management of pediatric type II supracondylar humerus fractures e-Poster 156 A single retrograde intramedullary nail technique for treatment of displaced proximal humeral fractures in adolescents: case series and review of the literature e-Poster 157 Acetabular “Fleck” sign: outcomes of surgical repair e-Poster 158 Avoiding trouble with pediatric capitellar fractures: unusual fracture variants, TRASH lesions, and treatment pearls e-Poster 159 Changes in femoral anteversion after intramedullary nail for pediatric femoral shaft fracture: a multicenter study e-Poster 160 Closed reduction techniques lead to fewer complications than open reductions in treating minimally and moderately displaced pediatric lateral humeral condyle fractures: a multicenter study e-Poster 161 Comminuted ulna fractures and nerve injuries: an investigation in Monteggia dislocations e-Poster 162 Diagnosis and treatment of lateral to medial diagonal injury of the elbow in children: concomitant medial epicondylar and radial neck fractures e-Poster 163 Do post-operative immobilization protocols and physical therapy impact return of elbow motion following pinning of supracondylar humerus type-III fractures? e-Poster 164 Effect of serum vitamin D levels in pediatric fracture occurrence e-Poster 165 Effects of casting material on reduction maintenance e-Poster 166 Elastic stable intramedullary nail treatment of pediatric femoral shaft fractures: fracture stability does not predict malunion or major complications e-Poster 167 Elastic stable intramedullary nail treatment of pediatric tibial shaft fractures: patients 75 pounds and over have higher risk malunion e-Poster 168 Enhanced radiographic union score (RUST) of adolescent tibia shaft fractures treated with hexapod circular external fixation: a multicenter study of 38 consecutive cases e-Poster 169 Financial implications associated with use of waterproof casting material in pediatric patients e-Poster 170 (Nominated for Best e-Poster) Healthcare utilization following closed reduction and percutaneous pinning of supracondylar humerus fractures e-Poster 171 Implant selection and complications in pediatric Monteggia fracture dislocations e-Poster 172 Incidence and long-term follow-up of lateral condyle fractures e-Poster 173 Interfacility transfer of pediatric supracondylar elbow fractures: transfer by ambulance shows no advantage in speed of transfer or prevention of complications e-Poster 174 Intimate partner violence in teenagers: why should the pediatric orthopedic surgeon care? e-Poster 175 Is tibial intramedullary nail placement safe when placed across open physes? e-Poster 176 Lateral overgrowth in surgically treated pediatric lateral condyle fractures e-Poster 177 Magnetic resonance imaging without sedation or anesthesia can guide treatment of minimally displaced pediatric lateral humeral condyle fractures e-Poster 178 Non-unions of surgically treated pediatric humeral lateral condylar fractures: risk factors and outcomes e-Poster 179 Novel radiographic predictors of diaphyseal forearm fracture malrotation: a cadaveric analysis e-Poster 180 (Nominated for Best e-Poster) Operative versus non-operative treatment of displaced proximal humerus fractures in adolescents: results of a prospective multicenter study e-Poster 181 Opioid prescription patterns 30 days after pediatric supracondylar humerus fracture closed reduction and percutaneous pinning e-Poster 182 Orthopedic fixation of skeletally immature ankle fractures in children and adolescents using bio-integrative implants e-Poster 183 Pediatric patients who sustain gunshot wound–related fractures are at higher risk of developing addiction and psychiatric disorders e-Poster 184 (Nominated for Best e-Poster) Pediatric talar neck fractures outcomes and complications: a 20-year review e-Poster 185 Please do not X-ray my healed fracture! utility of repeat radiographs during treatment of pediatric diaphyseal clavicle fractures e-Poster 186 Polymer-based biodegradable implants can be used safely instead of K-wires and screws in pediatric trauma: an experience of 495 children and 12 years e-Poster 187 Radiographic predictors of displacement in transitional ankle fractures: can we avoid a computed tomography scan on all patients? e-Poster 188 Rolling up the sleeve: patient characteristics and postoperative outcomes of surgically treated inferior pole patellar sleeve fractures e-Poster 189 Withdrawn e-Poster 190 The alarming trends in the epidemiology and risk factors of non-accidental fractures in children e-Poster 191 The effects of atypical fracture morphology on the need for open reduction in pediatric supracondylar humerus fractures e-Poster 192 (Nominated for Best e-Poster) There is no role for isolated closed reduction in displaced proximal humerus fractures in adolescents: results of a prospective multicenter study e-Poster 193 Trampoline-related fractures in 1063 consecutive children and adolescents e-Poster 194 Underdiagnosis of pediatric lateral ankle avulsion injuries: an ultrasound study e-Poster 195 Understanding the impact of family member presence during pediatric forearm fracture reductions in the emergency department e-Poster 196 (Nominated for Best e-Poster) Utility of follow-up X-ray in type I supracondylar humerus fracture e-Poster 197 Who should see my child? differences between pediatric and non-pediatric orthopedic specialists during treatment of pediatric diaphyseal clavicle fractures
  • Journal List
  • J Child Orthop
  • v.18(2 Suppl); 2024 Apr
  • PMC11062292

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EPOS/POSNA Abstract Book (1)

Link to Publisher's site

J Child Orthop. 2024 Apr; 18(2 Suppl): 1–440.

Published online 2024 May 1. doi:10.1177/18632521241239100

PMCID: PMC11062292

Copyright and License information PMC Disclaimer

WEDNESDAY, MAY 8

SESSION 1–TRAUMA

Room: Potomac Ballroom

Moderators: Jonathan G. Schoenecker and Melinda Witbreuk

OP-1

8:06 AM–8:10 AM

Radiological, clinical, and functional outcome of children with traumatic hip dislocation: review of 66 cases

Sara De Salvo, Shunyou Chen, Fabio Sammartino, Jeanne-Agathe Mujadiki Luesa, Yunan Lu, Wentao Wang, Liwei Shi, Lianyong Li, Vito Pavone, Federico Canavese, France-China-Italy Traumatic Hip Dislocation Study Group

CHU Lille, Lille, France

OP-2

8:11 AM–8:15 AM

Diaphyseal femur fractures in children under the age of 3—risk factors for non-accidental trauma: a CORTICES multi-center study

Manya Bali, Patricia E. Miller, Benjamin J. Shore, Scott B. Rosenfeld, CORTICES

Boston Children’s Hospital, Boston, MA, USA

OP-3

8:16 AM–8:20 AM

Increased odds of non-accidental traumatic fractures in pediatric patients with intellectual disability disorder: a stratified analysis

Rishi Gonuguntla, David Momtaz, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

8:21 AM–8:29 AM Discussion

OP-4

8:30 AM–8:34 AM

Ischial tuberosity avulsion fractures: treatment and return to sport in athletes with displaced fragments

Jayson Saleet, Eduardo Novais, Yi-Meng Yen, Mininder S. Kocher, Lyle J. Micheli, Benton E. Heyworth

Boston Children’s Hospital, Boston, MA, USA

OP-5

8:35 AM–8:39 AM

Pre-existing femoro-acetabular impingement is associated with pelvic avulsion fractures in adolescents: a matched cohort study

Miles Batty, Samantha L. Ferraro, Munif Hatem, Patricia E. Miller, Benton E. Heyworth, Sarah D. Bixby, Eduardo Novais

Boston Children’s Hospital, Boston, MA, USA

OP-6

8:40 AM–8:44 AM

An emerging healthcare crisis: trends in pediatric firearm injuries over time—analysis of over 1100 cases

Claire Sentilles, Elizabeth Lane Whitman, Keith Jayson Orland, Abu Mohd. Naser, Jonathan Rowland, Jeffrey R. Sawyer, Benjamin West Sheffer, David D. Spence, William C. Warner, Derek M. Kelly

Campbell Clinic, Germantown, TN, USA

8:45 AM–8:53 AM Discussion

OP-7

8:54 AM–8:58 AM

Loss of reduction in pediatric distal radius fractures: risk factors from a prospective multicenter registry

Apurva S. Shah, Zoe Elizabeth Belardo, Mark Leland Miller, Michael Willey, Susan T. Mahan, Divya Talwar, Rebecca Aguiar, Sana Bouajaj, Aspen Miller, Joshua Marino, Donald S. Bae, Pediatric Distal Radius Fracture Registry

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-8

8:59 AM–9:03 AM

Modified elastic stable intramedullary nailing, a new approach for distal metaphyso-diaphyseal junction of forearm in children

Elie Georges Saliba, Pauline Savidan, Clement Munoz, Yan Lefèvre

Hopital Des Enfants CHU de Bordeaux, Bordeaux, France

OP-9

9:04 AM–9:08 AM

Take it or leave it: prevalence and complications from hardware removal following pediatric fracture fixation

Vineet Desai, Scott J. Mahon, Lucas Hauth, Amanda Pang, Apurva S. Shah, Jason Anari

The Children’s Hospital of Philadelphia, Philadelphia, PA, USA

9:09 AM–9:17 AM Discussion

OP-10

9:18 AM–9:22 AM

Use of the bioabsorbable Activa IM-nail™ in pediatric diaphyseal forearm fractures: a prospective cohort study with at least 1-year follow-up*

David Goettsche, Morten Jon Andersen

Copenhagen University Hospital—Herlev and Gentofte, Copenhagen, Denmark

*Indicates a presentation in which the FDA has not cleared the drug and/or medical device for the use described (i.e., the drug or medical device is being discussed for an “off label” use).”

OP-11

9:23 AM–9:27 AM

Biodegradable magnesium implants—a game changer in pediatric trauma care

Romy Marek, Tavishi Singh, Nicole Gabriele Sommer, Annelie-Martina Weinberg

Medical University of Graz, Graz, Austria

OP-12

9:28 AM–9:32 AM

Biodegradable intramedullary nailing of severely displaced distal pediatric metaphyseal radius fractures

Marcell Benjamin Varga, Gergo Józsa, Zsófia Krupa, Tamás Kassai

Manninger Jenő Baleseti Központ, Budapest, Hungary

9:33 AM–9:41 AM Discussion

POSNA PRESIDENTIAL SPEAKER

Room: Potomac Ballroom

10:15 AM–10:20 AM Introduction

10:20 AM–10:40 AM Lawrence Lenke

SESSION 2—BEST OF SPINE

Room: Potomac Ballroom

Moderators: Carol C. Hasler and Peter O. Newton

10:41 AM–10:43 AM Welcome & Remarks

OP-13

10:44 AM–10:48 AM

Can scoliosis-specific exercises be performed with wearing brace in treating adolescent idiopathic scoliosis: an alternative use of scoliosis-specific exercises without sacrificing bracing hours

Charlene Fan, Michael To, Jason Cheung, Kenneth M.C. Cheung

The University of Hong Kong—Shenzhen Hospital, Shenzhen, People’s Republic of China

OP-14

10:49 AM–10:53 AM

Surgeon contoured versus pre-contoured patient-specific rods in adolescent idiopathic scoliosis: assessing global sagittal alignment

Sahir Jabbouri, Peter Joo, Wyatt David, Seongho Jeong, Jay Moran, Anshu Jonnalagadda, Dominick A. Tuason

Yale School of Medicine, New Haven, CT, USA

OP-15

10:54 AM–10:58 AM

Pulmonary function at minimum 10 years after segmental pedicle screw instrumentation for thoracic adolescent idiopathic scoliosis

Linda Helenius, Matti Mikael Ahonen, Johanna Syvänen, Ilkka J. Helenius

Helsinki University Hospital, Helsinki, Finland

10:59 AM–11:07 AM Discussion

OP-16

11:08 AM–11:12 AM

Osteotomies at the time of graduation surgery: how much do we get from them?

Tyler A. Tetreault, Tiffany Phan, Tishya A.L. Wren, Michael J. Heffernan, John B. Emans, Lawrence I. Karlin, Amer F. Samdani, Michael G. Vitale, Ilkka J. Helenius, Lindsay Andras, Pediatric Spine Study Group

Children’s Hospital Los Angeles, Los Angeles, CA, USA

OP-17

11:13 AM–11:17 AM

Is bracing after completion of Mehta casting worthwhile?

Tiffany Thompson, Carlos Monroig-Rivera, Mike M. O’Sullivan, Charles E. Johnston

Scottish Rite for Children, Dallas, TX, USA

OP-18

11:18 AM–11:22 AM

Limited fusion for congenital scoliosis: is it truly one and done?

Brandon Yoshida, Tyler A. Tetreault, Luke Christian Drake, Tiffany Phan, Jacquelyn Nicole Valenzuela-Moss, Tishya A. L. Wren, Lindsay Andras, Michael J. Heffernan

Children’s Hospital Los Angeles, Los Angeles, CA, USA

11:23 AM–11:31 AM Discussion

OP-19

11:32 AM–11:36 AM

Greater implant density does not improve pelvic obliquity and major curve correction in neuromuscular scoliosis

Patrick Thornley, Arlene R. Maheu, Kenneth Rogers, Paul D. Sponseller, Peter O. Newton, A. Noelle Larson, Joshua Pahys, Peter G. Gabos, M. Wade Shrader, Tracey P. Bastrom, Suken A. Shah, Harms Study Group

Nemours Children’s Health, Wilmington, DE, USA

OP-20

11:37 AM–11:41 AM

The effect of traction and spinal cord morphology on intraoperative neuromonitoring alerts

Evan Fene, Lydia Klinkerman, Charles E. Johnston, Jaysson T. Brooks, Megan Johnson

Scottish Rite for Children, Dallas, TX, USA

OP-21

11:42 AM–11:46 AM

What kind of kyphosis? Stratifying thoracolumbar kyphosis in achondroplasia

Luiz Carlos Almeida Da Silva, Yusuke Hori, Colleen P. Ditro, Kenneth Rogers, J. Richard Bowen, William G. Mackenzie, Stuart Mackenzie

Nemours Children’s Hospital—Delaware, Wilmington, DE, USA

11:47 AM–11:55 AM Discussion

SESSION 3A—ADOLESCENT IDIOPATHIC SCOLIOSIS (AIS)

Room: Potomac Ballroom

Moderators: Lindsay Andras and Dror Ovadia

2:00 PM–2:02 PM Welcome & Remarks

OP-22

2:03 PM–2:07 PM

Distribution of curve flexibility in idiopathic scoliosis—a descriptive study

Simon Blanchard, Matan Malka, Ritt Givens, Michael G. Vitale, Benjamin D. Roye

New York-Presbyterian Morgan Stanley Children’s Hospital, New York, NY, USA

OP-23

2:08 PM–2:12 PM

When is growth greatest? Spine and total body growth in idiopathic scoliosis through Sanders maturation stages 2, 3a, 3b, and 4

Yusuke Hori, Bryan Menapace, Burak Kaymaz, Luiz Carlos Almeida Da Silva, Norihiro Isogai, Sadettin Ciftci, Kenneth Rogers, Petya Yorgova, Andrea Mary Elsby, Peter G. Gabos, Suken A. Shah

Nemours Children’s Hospital, Wilmington, DE, USA

OP-24

2:13 PM–2:17 PM

The true cost of late referral in adolescent idiopathic scoliosis: a 5-year follow-up study

Emma Nadler, Jennifer Dermott, Dorothy Kim, David E. Lebel

The Hospital for Sick Children, Toronto, ON, Canada

2:18 PM–2:26 PM Discussion

OP-25

2:27 PM–2:31 PM

Battle of the braces: a comparison of brace efficacy in patients with adolescent idiopathic scoliosis treated with Providence, Boston-style, and Rigo-Cheneau braces

Leigh Davis, Amy Bridges, Julie Hantak, Hilary Harris, Sofie-Ellen Stroeva, Nikolay Braykov, Afrin Jahan, Nicholas D. Fletcher

Children’s Healthcare of Atlanta, Atlanta, GA, USA

OP-26

2:32 PM–2:36 PM

Improvement in axial rotation with bracing reduces risk of curve progression in patients with adolescent idiopathic scoliosis

Michael Fields, Christina Carin Rymond, Matan Malka, Ritt Givens, Matthew E. Simhon, Hiroko Matsumoto, Gerard F. Marciano, Afrain Z. Boby, Benjamin D. Roye, Michael G. Vitale

Children’s Hospital of New York, New York, NY, USA

OP-27

2:37 PM–2:41 PM

PROMIS-based assessment of brace compliance

Carlos Monroig-Rivera, David C. Thornberg, Chan-Hee Jo, Megan Johnson

Scottish Rite for Children, Dallas, TX, USA

2:42 PM–2:50 PM Discussion

OP-28

2:51 PM–2:55 PM

Can surgery be proposed to adolescent idiopathic scoliosis patients with structural lumbar curves associated with non-reducible iliolumbar angle?

Laurentiu-Cosmin Focsa, Louise Ponchelet, Mikael Finoco, Anne-Laure Simon, Brice Ilharreborde

Pediatric Orthopedic Department, CHU Robert Debré, Paris, France

OP-29

2:56 PM–3:00 PM

Utility of routine postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis

David Liu, Alexander Farid, Gabriel S. Linden, Danielle Cook, Craig Munro Birch, Michael T. Hresko, Daniel Hedequist, Grant Douglas Hogue

Boston Children’s Hospital, Boston, MA, USA

OP-30

3:01 PM–3:05 PM

A comparison of opioid-sparing versus opioid-containing postoperative pain management for idiopathic scoliosis

Michael Schallmo, Kayla Hietpas, Michael Paloski

Carolinas Medical Center/OrthoCarolina, Charlotte, NC, USA

3:06 PM–3:14 PM Discussion

OP-31

3:15 PM–3:19 PM

An accelerated postoperative protocol for discharging posterior spinal fusions home in less than 2 days: comparison of two matched cohorts

Chase Bauer, Jeffrey Kessler

Kaiser Permanente, Los Angeles, CA, USA

OP-32

3:20 PM–3:24 PM

Can surgery improve painful adolescent idiopathic scoliosis patients?

Arthur Poiri, Louise Ponchelet, Anne-Laure Simon, Florence Julien-Marsollier, Mikael Finoco, Brice Ilharreborde

Pediatric Orthopedic Department, Robert Debré University Hospital, Paris, France

OP-33

3:25 PM–3:29 PM

The postoperative decline in health-related quality of life for adolescents with idiopathic scoliosis undergoing spinal fusion

Adam A. Jamnik, Emily E. Lachmann, Anne-Marie D. Datcu, David C. Thornberg, Chan-Hee Jo, Karl E. Rathjen, Megan Johnson, Brandon A. Ramo

Scottish Rite for Children, Dallas, TX, USA

3:30 PM–3:38 PM Discussion

SESSION 3B—FOOT & ANKLE

Room: Woodrow Wilson Ballroom

Moderators: Deborah Eastwood and Steven Frick

2:00 PM–2:02 PM Welcome & Remarks

OP-34

2:03 PM–2:07 PM

The CoCo (Core Outcome ClubfOot) study: recurrence, with poorer clinical and quality of life outcomes, affects 37% of patients—an international multicenter observational study

Yael Gelfer, Sean Cavanagh, Anna Bridgens, Maryse Bouchard, Elizabeth Ashby, Deborah Eastwood

St George’s Hospital, London, UK

OP-35

2:08 PM–2:12 PM

Comparison of clinical outcomes, parental anxiety, and surgeon satisfaction during outpatient clinic versus operating room setting for Achilles tenotomy during Ponseti method of clubfoot correction—a randomized controlled trial

Karthick Sengoda Gounder Rangasamy, Premkumar Rajakumar, Nirmal Raj Gopinathan

Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India

OP-36

2:13 PM–2:17 PM

Effect of the abduction bracing on the contralateral foot in patients with unilateral clubfoot deformity: a longitudinal study

Kelly Jeans, Victoria Blackwood, Anthony Riccio

Scottish Rite for Children, Dallas, TX, USA

2:18 PM–2:26 PM Discussion

OP-37

2:27 PM–2:31 PM

Clubfoot relapse rates in idiopathic clubfoot using the Ponseti method: 65 years of data from a single institution

Jose A. Morcuende, Arianna Dalamaggas, Malynda Wynn

University of Iowa, Iowa City, IA, USA

OP-38

2:32 PM–2:36 PM

Comparative analysis of three anterior tibialis tendon transfer techniques in idiopathic clubfoot

Gregory Firth, Javier Masquijo, Alexandre Arkader, Victoria Allende Nores, Manoj Ramachandran

Royal London Hospital, London, UK

OP-39

2:37 PM–2:41 PM

Rebound of the radiological effect of anterior distal tibia epiphysiodesis in relapsed Ponseti-treated clubfoot patients after implant removal

Arnold T. Besselaar, Maria Christine Van Der Steen, Isabelle Van Tilburg

Máxima Medisch Centrum, Veldhoven, The Netherlands

2:42 PM–2:50 PM Discussion

OP-40

2:51 PM–2:55 PM

Is there a benefit to rigid fixation in calcaneal lengthening osteotomy in painful pediatric idiopathic flatfoot deformity? Comparing results of Kirschner wire versus plate fixation

Abhishek Tippabhatla, Beltran Torres-Izquierdo, Daniel Pereira, Zachary Meyer, Pooya Hosseinzadeh

Washington University School of Medicine, Saint Louis, MO, USA

OP-41

2:56 PM–3:00 PM

Nonunion rate of Evans osteotomy without fixation in pediatric flatfoot

Smitha Mathew, Brian Gallagher, Megan Miles, Gregory Paul Guyton

MedStar Union Memorial Hospital, Baltimore, MD, USA

OP-42

3:01 PM–3:05 PM

Improving detection of underlying neurologic etiology for pediatric cavovarus foot deformity: we can do better

Mike O’Sullivan, Michelle Christie, Rusty Lynn Hartman, Jacob Zide, Anthony Riccio

Scottish Rite for Children, Dallas, TX, USA

3:06 PM–3:14 PM Discussion

OP-43

3:15 PM–3:19 PM

Efficacy of Ponseti casting in arthrogryposis

Theresa A. Hennessey, Ferran Romero, Amanda Purcell, Angielyn San Juan, Bruce MacWilliams

Shriners Children’s Salt Lake City, Salt Lake City, UT, USA

OP-44

3:20 PM–3:24 PM

Is the proximal lateral epiphysiodesis of the first metatarsal effective in the correction of hallux valgus in the pediatric population?

Emanuel Seiça, Teresa Clode Araújo, Afonso Cardoso, Susana Norte, Monika Thüsing, Manuel Cassiano Neves

Hospital CUF Descobertas, Lisbon, Portugal

OP-45

3:25 PM–3:29 PM

The creation and validation of an ankle bone age atlas and data predicting remaining ankle growth

Andrew Pennock, James David Bomar, Jason Pedowitz, Stephen Carveth

Rady Children’s Hospital, San Diego, CA, USA

3:30 PM–3:38 PM Discussion

SESSION 3C—NEUROMUSCULAR & CEREBRAL PALSY

Room: Cherry Blossom Ballroom

Moderators: Jon Davids and Elke Viehweger

2:00 PM–2:02 PM Welcome & Remarks

OP-46

2:03 PM–2:07 PM

Hip progression after triradiate cartilage closure in ambulatory cerebral palsy: who needs continued surveillance?

Amelia M. Lindgren, Ali Asma, Kenneth Rogers, Freeman Miller, M. Wade Shrader, Jason Howard

Nemours Children’s Hospital, Wilmington, DE, USA

OP-47

2:08 PM–2:12 PM

How well does physical examination predict radiographic hip displacement in children with cerebral palsy?

Unni G. Narayanan, N. Susan Stott, Darcy Fehlings, H. Graham, Kishore Mulpuri, Benjamin J. Shore, M. Wade Shrader, Moon Seok Park, Tim Theologis, Marek Jozwiak, Jon R. Davids, Eva M. Ponten, Gunnar Hagglund, Bjarne Moeller-Madsen, Uri Givon, Deborah Eastwood, Tom F. Novacheck, Cerebral Palsy Hip Outcomes Project (CHOP)

The Hospital for Sick Children, Toronto, ON, Canada

OP-48

2:13 PM–2:17 PM

Femoral head shaft angle changes based on severity of neurologic impairment in children with cerebral palsy and spinal muscle atrophy

Luiz Carlos Almeida Da Silva, Yusuke Hori, Burak Kaymaz, Kenneth Rogers, Arianna Trionfo, Jason Howard, J. Richard Bowen, M. Wade Shrader, Freeman Miller

Nemours Alfred I. Dupont Children’s Hospital, Wilmington, DE, USA

2:18 PM–2:26 PM Discussion

OP-49

2:27 PM–2:31 PM

Proximal femur guided growth for spastic hip displacement in cerebral palsy children - long-term follow-up

Wei-Chun Lee, Szu-Yao Wang, Hsuan Kai Kao, Wen-E Yang, Chia-Hsieh Chang

Chang Gung Memorial Hospital, Taipei

OP-50

2:32 PM–2:36 PM

Does the addition of proximal femoral epiphysiodesis in neuromuscular hips improve caput valgum?

M. Bryant Transtrum, Katelyn S. Rourk, Julia Todderud, Christina Regan, Anthony A. Stans, William J. Shaughnessy, A. Noelle Larson, Todd A. Milbrandt, Emmanouil (Manos) Grigoriou

Mayo Clinic, Rochester, MN, USA

OP-51

2:37 PM–2:41 PM

Medialization at the osteotomy site may reduce relapse after varus de-rotational osteotomy (VDRO) of the proximal femur in cerebral palsy

Frederico Vallim, Eduardo Duarte Pinto Godoy, Juliana Lyra, Joao Antonio Matheus Guimaraes, Marcello Henrique Nogueira-Barbosa, H. Graham

Hospital Estadual da Criança, Rio de Janeiro, Brazil

2:42 PM–2:50 PM Discussion

OP-52

2:51 PM–2:55 PM

Combined pelvic osteotomy and proximal femur guided growth for serious hip subluxation in cerebral palsy children

Kuan-wen Wu, Hsiang Chieh Hsieh, Chia-Che Lee, Ting-ming Wang, Ken N. Kuo

National Taiwan University Hospital, Taipei

OP-53

2:56 PM–3:00 PM

Medium-term results after femoral head resection and subtrochanteric valgus osteotomy in children and adolescents with cerebral palsy

Ralf D. Stuecker, Madeleine Marowsky, Oliver Jungesblut, André Strahl, Martin Rupprecht

Childrens Hospital Hamburg-Altona, Hamburg, Germany

OP-54

3:01 PM–3:05 PM

The association between hip displacement, scoliosis, and pelvic obliquity in 106 non-ambulatory patients with cerebral palsy: a longitudinal, population-based study

Terje Terjesen, Svend Vinje, Thomas Kibsgård

Oslo University Hospital, Rikshospitalet, Oslo, Norway

3:06 PM–3:14 PM Discussion

OP-55

3:15 PM–3:19 PM

The evaluation of total hip replacement in management of spastic painful hip dislocation in cerebral palsy

Andrzej Sionek, Bartosz Babik, Jaroslaw Czubak

Department of Orthopedic, Pediatric Orthopedic and Traumatology, Gruca Teaching Hospital CMKP, Warsaw-Otwock, Masovia, Poland

OP-56

3:20 PM–3:24 PM

Inter-rater reliability of a photo-based modified foot posture index (MFPI) in identifying severity of foot deformity in children with cerebral palsy

Beltran Torres-Izquierdo, Jason Howard, Sean Tabaie, Mara S. Karamitopoulos, Benjamin J. Shore, Monica Payares-Lizano, Robert Lane Wimberly, M. Wade Shrader, Kristan A. Pierz, Andrew Gregory Georgiadis, Jason Rhodes, Jon R. Davids, Rachel Mednick Thompson, Pooya Hosseinzadeh

Washington University School of Medicine, Saint Louis, MO, USA

OP-57

3:25 PM–3:29 PM

Impact of femoral derotation osteotomy and equinus varus foot correction on transverse plane asymmetry in patients with hemiplegic cerebral palsy

Mauro Cesar Morais Filho, Marcelo Hideki Fujino, Catia Miyuki Kawamura, Jose Augusto Fernandes Lopes, Fernanda Piumbini Azevedo

AACD, São Paulo, Brazil

3:30 PM–3:38 PM Discussion

SESSION 3D—INFECTIONS & TUMORS

Room: National Harbor 2-3

Moderators: James McCarthy and Marta Salom

2:00 PM–2:02 PM Welcome & Remarks

OP-58

2:03 PM–2:07 PM

Aspirations dashed: serum neutrophil-to-lymphocyte ratio is not a good predictor of septic arthritis of the hip and knee in pediatric patients

Christopher John DeFrancesco, David Peter VanEenenaam, Carter Hall, Vineet Desai, Kevin Jossue Orellana, Wudbhav N. Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-59

2:08 PM–2:12 PM

Severity of osteomyelitis—the bug is the problem

Haemish A. Crawford, Anna McDonald, Simon Swift, Jillian Cornish, Reece Joseph, Sophia Huiyao Hamada-Zhu, Christina Straub, Brya Matthews

Starship Children’s Hospital, Auckland, New Zealand

OP-60

2:13 PM–2:17 PM

Featherweight versus heavyweight of pediatric musculoskeletal infections: Kingella versus the titans of staphylococcus and streptococcus

Brian Quincey Hou, Malini Anand, William Franklin Hefley, Katherine Sara Hajdu, Stephen Chenard, Anoop Chandrashekar, Naadir Jamal, Michael Joseph Greenberg, Courtney Baker, Stephanie N. Moore-Lotridge, Jonathan G. Schoenecker

Vanderbilt University Medical Center, Nashville, TN, USA

2:18 PM–2:26 PM Discussion

OP-61

2:27 PM–2:31 PM

Low prevalence of anaerobic bacteria in pediatric septic arthritis makes obtaining anaerobic cultures of questionable value

Maia Regan, David A. Spiegel, Kenneth Smith, Keith D. Baldwin

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-62

2:32 PM–2:36 PM

Tiny humans versus a deadly disease: an epidemiologic review of necrotizing fasciitis in pediatric patients

Stephanie N. Moore-Lotridge, Samuel Johnson, Wendy Ramalingam, Jonathan G. Schoenecker

Vanderbilt University Medical Center, Nashville, TN, USA

OP-63

2:37 PM–2:41 PM

Awake biopsy in pediatric patients with suspected musculoskeletal malignancy is safe, feasible, cost-effective and reduces time to tissue diagnosis

Huw R.F. Walters, Alpesh Kothari, Max Mifsud, Andrew Wainwright, Karen Partington

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

2:42 PM–2:50 PM Discussion

OP-64

2:51 PM–2:55 PM

Comparison of diaphyseal reconstruction techniques of the lower limbs in childhood malignant tumors: long-term results

Edouard Haumont, Lys Budiartha, Manon Pigeolet, Marine De Tienda, Frank Fitoussi, Stephanie Pannier, Eric Mascard

Necker—Enfants Malades, Paris, France

OP-65

2:56 PM–3:00 PM

Survivorship of custom-made non-invasive extendable implants in pediatric sarcoma patients

Max Mifsud, Ruben Thumbadoo, Tim Theologis

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

OP-66

3:01 PM–3:05 PM

Sufficiency of isolated vascularized fibula for intercalary reconstruction

Laura Saenz, Sevan Hopyan

The Hospital for Sick Children, Toronto, ON, Canada

3:06 PM–3:14 PM Discussion

OP-67

3:15 PM–3:19 PM

Femoral head cartilage window approach combined with artificial bone implantation for treatment of epiphyseal chondroblastoma in children

Xuemin Lyu, Zheng Yang

Beijing Jishuitan Hospital, Beijing, People’s Republic of China

OP-68

3:20 PM–3:24 PM

Evidence-based recommendations for treating pediatric desmoid tumors: consensus of the Desmoid Tumor Working Group*

Benjamin A. Alman, The Desmoid Tumor Working Group

Duke University, Durham, NC, USA

*Indicates a presentation in which the FDA has not cleared the drug and/or medical device for the use described (i.e., the drug or medical device is being discussed for an “off label” use).”

OP-69

3:25 PM–3:29 PM

Retrospective analysis and characterization of avascular necrosis in pediatric leukemia/lymphoma patients using BLAST classification

Amin Alayleh, Hiba Naz, Vanessa Taylor, Taylor Renee Johnson, Saima Farook, Grady Harrison Hofmann, Chiamaka Nneka Obilo, Katie Harbacheck, Tara Anne Laureano, Stephanie M. Smith, Karen Chao, Stuart B. Goodman, Kevin G. Shea

Stanford University, Palo Alto, CA, USA

3:30 PM–3:38 PM Discussion

SESSION 4A—CONGENITAL, SYNDROMIC, & DYSPLASIAS

Room: Cherry Blossom Ballroom

Moderators: Stephanie Boehm and Klane White

4:12 PM–4:14 PM Welcome & Remarks

OP-70

4:15 PM–4:19 PM

Survival of telescoping rods decreases with successive surgeries in patients with osteogenesis imperfecta

Cynthia Nguyen, Chris Makarewich, Selina Poon, Robert Hyun Cho, Theresa A. Hennessey

Shriners for Children Medical Center, Pasadena, CA, USA

OP-71

4:20 PM–4:24 PM

Augmentation of submuscular plates in addition to telescopic rodding in the management of long bone fractures in patients with osteogenesis imperfecta

Baris Gorgun, Onur Oto, Sema Ertan Birsel, Ozan Ali Erdal, Muharrem Inan

Ortopediatri Istanbul, Academy of Pediatric Orthopedics, Istanbul, Turkey

OP-72

4:25 PM–4:29 PM

Long-term outcomes of intramedullary nails in osteogenesis imperfecta: fewer surgeries and longer survival times with telescoping rods in patients with over 10-year follow-up

Cynthia Nguyen, Chris Makarewich, Selina Poon, Robert Hyun Cho, Theresa A. Hennessey

Shriners for Children Medical Center, Pasadena, CA, USA

4:30 PM–4:38 PM Discussion

OP-73

4:39 PM–4:43 PM

Prophylactic intramedullary rodding following femoral lengthening in patients with achondroplasia and hypochondroplasia

Cesar G. Fontecha, Pilar Rovira Martí

Sant Joan de Déu Children Hospital Barcelona, Esplugues de Llobregat (Barcelona), Spain

OP-74

4:44 PM–4:48 PM

Spinal surgery in achondroplasia: causes of reoperation and reduction of risks

Arun R. Hariharan, Hans K. Nugraha, Aaron Huser, David S. Feldman

Paley Orthopedic & Spine Institute, West Palm Beach, FL, USA

OP-75

4:49 PM–4:53 PM

Collagen-type 2 skeletal dysplasias: key clinical, radiographic, and MRI findings guide cervical stabilization decision-making

Bryan Menapace, Colleen P. Ditro, Kenneth Rogers, Jeffrey Campbell, William G. Mackenzie, Stuart Mackenzie

A.I. duPont/Nemours Children’s Hospital, Wilmington, DE, USA

4:54 PM–5:02 PM Discussion

OP-76

5:03 PM–5:07 PM

Screening and early management of hips in children with spina bifida following prenatal surgical closure

Domenic Grisch, Aurelia Hof, Britta Krautwurst, Thomas Dreher

University Children’s Hospital Zurich, Zurich, Switzerland

OP-77

5:08 PM–5:12 PM

Does open reduction of arthrogrypotic hips cause stiffness?

Harold J.P. Van Bosse, David Teytelbaum, Solomon Samuel, Vinieth Bijanki, Stephen Silva

St. Louis University, St. Louis, MO, USA

OP-78

5:13 PM–5:17 PM

Burosomab reduces the need for hemiepiphysiodesis in hypophosphatemic rickets

Christopher James Marusza, Zakir Haider, Kelvin Miu, Daniel Thomas Fontannaz, Deborah Eastwood

Great Ormond Street Hospital for Children, London, UK

5:18 PM–5:26 PM Discussion

SESSION 4B—HAND & UPPER EXTREMITY

Room: National Harbor 2-3

Moderators: Yrjänä Nietosvaara and Julie Samora

4:12 PM–4:14 PM Welcome & Remarks

OP-79

4:15 PM–4:19 PM

Ethnicity is a risk factor for permanent brachial plexus birth injury

Petra Grahn, Aarno Yrjana Nietosvaara, Mika Gissler, Marja Kaijomaa

Helsinki University Hospital, New Children’s Hospital, Helsinki, Finland

OP-80

4:20 PM–4:24 PM

Sprengel deformity: what is the functional outcome and quality of life after surgery according to the EQ-5D-Y and the short version of Disabilites of the Arm, Shoulder, and Hand Questionnaire (quickDASH)?

Carina Antfang, Adrien Frommer, Georg Gosheger, Robert Roedl, Andrea Marira Laufer, Gregor Toporowski, Henning Tretow, Jan Duedal Rölfing, Bjoern Vogt

Department of Pediatric Orthopedics, Deformity correction and Foot surgery, University Hospital, Muenster, Germany

OP-81

4:25 PM–4:29 PM

Medium- and long-term clinical and functional outcomes of modified Green’s procedure for Sprengel shoulder in children

Giovanni Trisolino, Marco Todisco, Paola Zarantonello, Giovanni Di Gennaro, Alessandro Depaoli, Gino Rocca

IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy

4:30 PM–4:38 PM Discussion

OP-82

4:39 PM–4:43 PM

Osteot-OH MY! Contemporary surgical techniques may reduce revision rates following preaxial polydactyly reconstruction

Eliza Buttrick, Sarah L. Struble, Shaun Mendenhall, Benjamin Chang, Sulagna Sarkar, Apurva S. Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-83

4:44 PM–4:48 PM

Surgical versus nonsurgical management of pediatric ganglia—a cost and outcomes analysis

Bryce Bell, Umar Ghilzai, Zuhair Jameel Mohammed, Christine Yin, Abdullah Ghali, Qianzi Zhang

Baylor College of Medicine, Houston, TX, USA

OP-84

4:49 PM–4:53 PM

Tendon transfer in spastic cerebral palsy upper limb

Mahzad Javid, G. Hossain Shahcheraghi, Hadi Gerami

Shiraz Medical University, Shiraz, Iran

4:54 PM–5:02 PM Discussion

OP-85

5:03 PM–5:07 PM

Factors influencing return of elbow motion following pinning of displaced supracondylar humeral fractures

Akbar Nawaz Syed, Pooja Nilesh Balar, Margaret Bowen, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-86

5:08 PM–5:12 PM

Development of a new classification for forearm involvement in patients with multiple hereditary exostosis (MHE) using the Delphi process

Carley Vuillermin, Maria F. Canizares, CoULD Study Group

Boston Children’s Hospital, Boston, MA, USA

OP-87

5:13 PM–5:17 PM

Flippin’ out over gymnast wrist: presentation and treatment of distal radial physeal stress syndrome in young gymnasts

David Peter VanEenenaam, Scott J. Mahon, Naomi Brown, Joseph Yellin, Apurva S. Shah

The Children’s Hospital of Philadelphia, Philadelphia, PA, USA

5:18 PM–5:26 PM Discussion

SESSION 4C—NEUROMUSCULAR

Room: Woodrow Wilson Ballroom

Moderators: Unni Narayanan and Ana Presedo

4:12 PM–4:14 PM Welcome & Remarks

OP-88

4:15 PM–4:19 PM

Cerebral palsy in the British Orthopedic Surgery Surveillance Study (CPinBOSS)

Marie-Caroline Nogaro, Julie Stebbins, Daniel Christopher Perry, Tim Theologis

University of Oxford, Oxford, UK

OP-89

4:20 PM–4:24 PM

Health-related quality of life in ambulatory children with physical disabilities

Chris Church, Sana Patil, Stephanie Butler, Freeman Miller, Jose De Jesus Salazar-Torres, Nancy Lennon, M. Wade Shrader, Maureen Donohoe, Faithe Rassias Kalisperis, Stuart Mackenzie, L. Reid Boyce Nichols, Nemours Gait Lab

Nemours A.I. Dupont Hospital for Children, Wilmington, DE, USA

OP-90

4:25 PM–4:29 PM

What is the prevalence of depressive symptoms and antidepressant use among adult patients with cerebral palsy?

Michael G. Vitale,Chun Wai Hung, Daniel Linhares, Afrain Z. Boby, Hiroko Matsumoto, Joshua E. Hyman, David P. Roye

Columbia University Medical Center, NY, USA

4:30 PM–4:38 PM Discussion

OP-91

4:39 PM–4:43 PM

Accuracy and reliability of mobile app–enhanced observational gait analysis in children with cerebral palsy

Donald T. Kephart, Jon R. Davids, Vedant A. Kulkarni

Shriners Children’s Northern California, Sacramento, CA, USA

OP-92

4:44 PM–4:48 PM

The risk factors associated with increased anterior pelvic tilt in ambulatory children with cerebral palsy

Chris Church, Jose De Jesus Salazar-Torres, Tanmayee Joshi, Nancy Lennon, Thomas Shields, John Henley, Freeman Miller, M. Wade Shrader, Jason Howard

Nemours Children’s Health, Wilmington, DE, USA

OP-93

4:49 PM–4:53 PM

The association between increase in knee range of motion and patient satisfaction after rectus femoris transfer in cerebral palsy

Mauro Cesar Morais Filho, Marcelo Hideki Fujino, Catia Miyuki Kawamura, Jose Augusto Fernandes Lopes, Ageu Saraiva

Ageu Saraiva AACD, São Paulo, Brazil

4:54 PM–5:02 PM Discussion

OP-94

5:03 PM–5:07 PM

Is the CPCHILD questionnaire responsive—assessing HRQoL changes and performance of the CPCHILD after hip and spine surgery in children with severe cerebral palsy

Lennert Plasschaert, Patricia E. Miller, Rachel DiFazio, Brian D. Snyder, Colyn Watkins, Travis Matheney, Benjamin J. Shore

Boston Children’s Hospital, Boston, MA, USA

OP-95

5:08 PM–5:12 PM

Disease-modifying therapy changed the natural course of spinal muscular atrophy type 1: what about spine and hip?

Niyazi Erdem Yasar, Guzelali Ozdemir, Elif Uzun Ata, Naim Ata, Mahir Mustafa Ülgü, Ebru Dumlupinar, Suayip Birinci, Izzet Bingöl, Senol Bekmez

Ankara Bilkent Children’s Hospital, Ankara, Turkey

OP-96

5:13 PM–5:17 PM

Increased knee range of motion in patients with arthrogryposis: minimum 2-year follow-up

Aaron Huser, Michael William Brown, Arun R. Hariharan, Hans K. Nugraha, David S. Feldman

Paley Orthopedic and Spine Institute, West Palm Beach, FL, USA

5:18 PM–5:26 PM Discussion

SESSION 4D—SLIPPED CAPITAL FEMORAL EPIPHYSIS

Room: Potomac Ballroom

Moderators: Catharina Chiari and Wudbhav N. Sankar

4:12 PM–4:14 PM Welcome & Remarks

OP-97

4:15 PM–4:19 PM

Obesity-related alterations in capital femoral epiphysis morphology: an extensive analysis of 8717 hips utilizing automated 3D-CT imaging

Eduardo Novais, Mohammadreza Movahhedi, Mallika Singh, Nazgol Tavabi, Shanika De Silva, Sarah D. Bixby, Ata M. Kiapour

Boston Children’s Hospital, Boston, MA, USA

OP-98

4:20 PM–4:24 PM

Intraoperative perfusion monitoring does not reliably predict osteonecrosis following treatment of unstable SCFE

Bridget Ellsworth, Julianna Lee, Wudbhav N. Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-99

4:25 PM–4:29 PM

Bone scintigraphy can predict post-operative femoral head avascular necrosis in children with hip trauma and slipped capital femoral epiphysis

Patrick Curran, Katharine Hollnagel, James David Bomar, V. Salil Upasani

Rady Children’s Hospital, San Diego, CA, USA

4:30 PM–4:38 PM Discussion

OP-100

4:39 PM–4:43 PM

Epiphyseal stability increases specificity of the Loder classification system in prognosticating AVN after slipped capital femoral epiphysis

Katherine Sara Hajdu, Emilie Amaro Zoldos, Courtney Baker, Simone Herzberg, Benjamin Asbury, Stephanie N. Moore-Lotridge, Kevin Michael Dale, David Ebenezer, Nathaniel Lempert, Craig R. Louer, Jeffrey E. Martus, Gregory A. Mencio, Jonathan G. Schoenecker, Vanderbilt SCFE Study Group

Vanderbilt University Medical Center, Nashville, TN, USA

OP-101

4:44 PM–4:48 PM

Rate and risk factors for contralateral slippage in adolescents treated for slipped capital femoral epiphysis: a comprehensive analysis of 3528 cases

David Momtaz, Rishi Gonuguntla, Aaron Singh, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh

Washington University School of Medicine, Saint Louis, MO, USA

OP-102

4:49 PM–4:53 PM

Temporary in situ pinning with subsequent modified Dunn is a safe alternative to primary modified Dunn

Jordyn Adams, Graham Whiting, Jordan Archer, Courtney Selberg

Children’s Hospital Colorado, Aurora, CO, USA

4:54 PM–5:02 PM Discussion

OP-103

5:03 PM–5:07 PM

Risk factors of vitamin D deficiencies on SCFE development

David Momtaz, Abhishek Tippabhatla, Rishi Gonuguntla, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh, Zachary Meyer

Washington University School of Medicine, Saint Louis, MO, USA

OP-104

5:08 PM–5:12 PM

Intertrochanteric Imhauser’s osteotomy combined with osteochondroplasty in management of slipped capital femoral epiphysis

Mostafa Baraka

Ain Shams University, Cairo, Egypt

OP-105

5:13 PM–5:17 PM

Long-term outcomes for total joint arthroplasties in pediatric and young adult populations

Andrea Rogers, Gabrielle J. Patin, Carson L. Keeter, Nathan Donaldson

Children’s Hospital Colorado, Aurora, CO, USA

5:18 PM–5:26 PM Discussion

THURSDAY, MAY 9

SESSION 5—BAG O’ BONES

Room: Potomac Ballroom

Moderators: John “Jack” Flynn and Manoj Ramchandran

9:45 AM–9:50 AM Welcome & Remarks

OP-106

9:51 AM–9:55 AM

Universal ultrasound screening for DDH may be cost effective: a Markov decision analysis model incorporating the entire lifespan

Joshua Bram, Drake Glenn LeBrun, Peter Cirrincione, Erikson Nichols, Bridget Ellsworth, Ernest Sink, Emily Dodwell

Hospital for Special Surgery, New York, NY, USA

OP-107

9:56 AM–10:00 AM

Deep-learning algorithm accurately measures migration percentage on hip surveillance radiographs

Vedant A. Kulkarni, Chun-Hsiao Yeh, Anna Kay, Michael Eli Firtha, Marie Villalba, Patrick Donohue, H. Graham, Unni G. Narayanan, Stella X. Yu

Shriners Children’s Northern California, Sacramento, CA, USA

OP-108

10:01 AM–10:05 AM

Suprainguinal fascia iliaca nerve blocks outperform epidural analgesia in patients undergoing periacetabular osteotomy

David Peter VanEenenaam, Stefano Cardin, Wallis Muhly, Wudbhav N. Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

10:06 AM–10:14 AM Discussion

OP-109

10:15 AM–10:19 AM

Virtual children’s fracture clinic—a prospective study of 5536 patients confirming that efficiency and cost saving does not compromise safety

Anish P. Sanghrajka, Kareem Edres, Aly Pathan, Matthew Edward Kenneth Goodbun, Joe Hwong Pang, Graeme Carlile, Rajiv Merchant; Helen Chase

Norfolk & Norwich University Hospitals, Norwich, UK

OP-110

10:20 AM–10:24 AM

Prevalence of Osteochondromas in the Spine in Patients with Multiple Hereditary Exostoses

Carlos Monroig-Rivera, Lauren Bockhorn, Brenda Santillan, David C. Thornberg, Karl E. Rathjen

Scottish Rite for Children, Dallas, TX, USA

OP-111

10:25 AM–10:29 AM

Predictors of complication in pediatric hardware removal

Pablo Coello, David A. Hsiou, Luke Austin Nordstrom, Todd Phillips, Rachel Silverstein, Scott B. Rosenfeld

Texas Children’s Hospital, Houston, TX, USA

10:30 AM–10:38 AM Discussion

OP-112

10:39 AM–10:43 AM

Significant improvement in health-related quality of life following surgical treatment of congenital muscular torticollis among a 2-year follow-up cohort of children, adolescents, and young adults

Per Reidar Hoiness, Anja Medbø

Oslo University Hospital, Oslo, Norway

OP-113

10:44 AM–10:48 AM

The hidden consequences of advanced operative spine imaging in children: do the suggested benefits of intraoperative computed tomography and navigation in posterior spinal fusion for adolescent idiopathic scoliosis outweigh the possible lifetime oncological risks of increased radiation exposure?

Bram Verhofste, Brendan M. Striano, Alex Crawford, Andrew M. Hresko, Andrew Schoenfeld, Andrew K. Simpson, Daniel Hedequist

Boston Children’s Hospital, Boston, MA, USA

OP-114

10:49 AM–10:53 AM

Radiation shielding during bedside fluoroscopy reduces radiation exposure to pediatric patients

Steven Zhang, William Huffman, Caroline Fay, Margaret Bowen, Divya Talwar, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

10:54 AM–11:02 AM Discussion

OP-115

11:03 AM–11:07 AM

Suicidal ideation in pediatric orthopedic patients

Taylor Zak, Whitney Meghan Herge, Chan-Hee Jo, Anthony Riccio

Scottish Rite for Children, Dallas, TX, USA

OP-116

11:08 AM–11:12 AM

From bytes to bones: assessing the ability of ChatGPT to educate patients and families in pediatric orthopedic surgery

Alex Gornitzky, Raghav Badrinath, Joseph Yellin, Brett R. Lullo

Lurie Children’s Hospital of Chicago, Chicago, IL, USA

OP-117

11:13 AM–11:17 AM

Greater obstetric barriers for female orthopedic surgeons compared to the general population and peer physicians

Emily Reeson, Gwen Grimsby, Melissa Esparza, Heather Menzer

Phoenix Children’s Hospital, Phoenix, AZ, USA

1:18 AM–11:26 AM Discussion

FRIDAY, MAY 10

SESSION 6—AWARD–NOMINATED PAPERS PART I

Room: Potomac Ballroom

Moderators: Nicholas Fletcher and Ralph Sakkers

8:00 AM–8:05 AM Welcome & Remarks

OP-118

8:06 AM–8:10 AM

Full-thickness skin graft versus hyaluronic acid skin graft substitute in syndactyly release: a randomized trial

Ann Van Heest, Deborah Bohn, Jamie N. Price, Susan A. Novotny, Tonye Sylvanus

Gillette Children’s Specialty Healthcare, St. Paul, MN, USA

OP-119

8:11 AM–8:15 AM

Outcomes following operative versus non-operative treatment of completely displaced midshaft clavicle fractures in adolescent baseball players and other overhead athletes

Eric W. Edmonds, David D. Spence, Michael Quinn, Benton E. Heyworth, FACTS Study Group

Boston Children’s Hospital, Boston, MA, USA

8:16 AM–8:23 AM Discussion

OP-120

8:24 AM–8:28 AM

Two-year patient-reported outcomes and graft rupture following ACL reconstruction in skeletally immature athletes: results from the PLUTO (pediatric ACL: understanding treatment options) prospective cohort study

Mininder S. Kocher, Lauren E. Hutchinson, Danielle Cook, Jeffrey Kay, Benton E. Heyworth, PLUTO Study Group

Boston Children’s Hospital, Boston, MA, USA

OP-121

8:29 AM–8:33 AM

Fabrication of a biomimetic 3D-printed scaffold for the treatment of large osteochondral defects in an adolescent porcine model: outcomes at 6 months

Sanjoy Kumar Ghorai, Patrick William Whitlock, Sumit Murab, Anish Gangavaram, Chia-Ying James Lin, Jenna Hall

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

8:34 AM–8:41 AM Discussion

OP-122

8:42 AM–8:46 AM

Long-term outcome of nonoperative treatment of Perthes disease—244 hips with a mean follow-up of 48 years

Anders Wensaas, Chiara Blatti, Terje Terjesen, Stefan Huhnstock

Department for Children’s Orthopaedics and Reconstructive Surgery, Division of Orthopedic Surgery, Oslo University Hospital, Oslo, Norway

OP-123

8:47 AM–8:51 AM

In situ fixation of slipped capital femoral epiphysis carries an over 40% risk for later total hip replacement during a long-term follow-up

Thomas Schlenzka, Joni Serlo, Timo Juhani Viljakka, Kaj Tallroth, Ilkka J. Helenius

Helsinki University Hospital, Helsinki, Finland

8:52 AM–8:59 AM Discussion

EPOS PRESIDENTIAL SPEAKER

Room: Potomac Ballroom

9:00 AM–9:05 AM Introduction

9:05 AM–9:25 AM Manuel Cassiano Neves

SESSION 7—AWARD–NOMINATED PAPERS PART II

Room: Potomac Ballroom

Moderators: Hakan Omeroglu and Daniel Sucato

OP-124

9:55 AM–9:59 AM

Mid-term outcomes following vertebral body tethering: a single-center cohort with 5+ years of follow-up

Daniel G. ho*rnschemeyer, Sam Hawkins, Nicole Tweedy, Melanie E. Boeyer

University of Missouri, Columbia, MO, USA

OP-125

10:00 AM–10:04 AM

A CNP analog as adjuvant treatment for moderate-to-severe osteogenesis imperfecta in the growing mouse: a pilot study

Jack Mulcrone, Ketsia Seide, Erin Carter, Nancy Pleshko, Cathleen L. Raggio

Hospital for Special Surgery, New York, NY, USA

10:05 AM–10:12 AM Discussion

OP-126

10:13 AM–10:17 AM

Bi-lateral and bi-level erector spinae plane block in pediatric idiopathic scoliosis surgery: a randomized, double-blind, controlled trial

Malgorzata Domagalska, Piotr Janusz, Tomssz Reysner, Grzegorz Kowalski, Juliusz Huber, Przemyslaw Daroszewski, Tomasz Kotwicki

University of Medical Sciences, Poznan, Poland

OP-127

10:18 AM–10:22 AM

Local wound infiltration reduces acute postoperative opioid requirements in AIS: a prospective double-blind randomized controlled trial

Craig Munro Birch, Sydney Lee, Kelsey Mikayla Flowers Zachos, Shanika De Silva, Grant Douglas Hogue, Michael T. Hresko, Daniel Hedequist

Boston Children’s Hospital, Boston, MA, USA

10:23 AM–10:30 AM Discussion

OP-128

10:31 AM–10:35 AM

Efficacy of a multimodal surgical site injection in pediatric patients with cerebral palsy undergoing hip reconstruction: a randomized controlled trial

Danielle Brown, Christina-Angèle Kaulueloa’ainalani Sun, Daniel McBride, Bailey Young, Vineeta Swaroop, Rachel Mednick Thompson

UCLA, Los Angeles, CA, USA

OP-129

10:36 AM–10:40 AM

Analysis of regenerate bone formation using internal lengthening nails in a large animal model: a pilot study

Christopher A. Iobst, Anirejuoritse Bafor, Aidan Gene Isler, Sara McBride-Gagyi, Kell Sprangel

Nationwide Children’s Hospital, Columbus, OH, USA

10:41 AM–10:48 AM Discussion

OP-130

10:49 AM–10:53 AM

Long-term results of epiphyseal distraction prior to resection (Cañadell’s technique) in 169 patients with metaphyseal pediatric bone sarcomas

Jorge Gómez-Álvarez, José María Lamo-Espinosa, Rocío López, Mikel San-Julián

Clínica Universidad de Navarra, Pamplona, Navarra, Spain

OP-131

10:54 AM–10:58 AM

Use of serum biomarkers and cytokines to differentiate septic arthritis, osteomyelitis, and transient synovitis in pediatric and adolescent patients

Nichelle Enata, Kirsten Brouillet, Ling Chen, Kim Quayle, Scott J. Luhmann

Washington University School of Medicine, St Louis, MO, USA

10:59 AM–11:06 AM Discussion

OP-132

11:07 AM–11:11 AM

Kicking the can in DDH: the impact of age on outcomes following secondary reconstructive surgery for residual dysplasia

Shamrez Haider, Laura M. Mayfield, Corey Gill, Harry K.W. Kim, Daniel J. Sucato, David A. Podeszwa, William Zachary Morris

Scottish Rite for Children, Dallas, TX, USA

OP-133

11:12 AM–11:16 AM

Late-diagnosed DDH is rare in Finland with universal clinical screening program complemented with selective ultrasonography

Emma Luoto, Jenni Katariina Jalkanen, Ilari Kuitunen, Reijo Sund, Aarno Yrjana Nietosvaara

Kuopio University Hospital, Kuopio, Finland

11:17 AM–11:24 AM Discussion

SOCIETY AWARD WINNERS

Room: Potomac Ballroom

Pro Maximis Meritis Award

11:25 AM–11:30 AM Introduction

11:31 AM–11:41 AM Deborah Eastwood, MD

Distinguished Achievement Award

11:44 AM–11:49 AM Introduction

11:50 AM–12:00 PM Charles Johnston, MD

SESSION 8A—VERTEBRAL BODY TETHERING (VBT) & SAGITTAL PROFILE

Room: Potomac Ballroom

Moderators: Firoz Miyanji and Frank Plasschaert

2:00 PM–2:02 PM Welcome & Remarks

OP-134

2:03 PM–2:07 PM

Navigation versus fluoroscopy for anterior VBT screw placement, analysis of 530 screws with confirmatory 3D imaging

Chunho Chen, Jimmy Daher, A. Noelle Larson, Todd A. Milbrandt, Lawrence L. Haber

Ochsner Hospital for Children, New Orleans, LA, USA

OP-135

2:08 PM–2:12 PM

Growth modulation response in thoracic VBT depends primarily on magnitude of concave vertebral body growth

Craig R. Louer, V. Salil Upasani, Jennifer Hurry, Hui Nian, Christine L. Farnsworth, Peter O. Newton, Stefan Parent, Pediatric Spine Study Group, Ron El-Hawary

Vanderbilt University Medical Center, Nashville, TN, USA

OP-136

2:13 PM–2:17 PM

Spontaneous correction of the thoracic curve in Lenke 5 patients: lumbar vertebral body tether (VBT) versus posterior fusion

Jennifer Marie Bauer, Suken A. Shah, Jaysson T. Brooks, Baron S. Lonner, Amer F. Samdani, Firoz Miyanji, Peter O. Newton, Burt Yaszay, Harms Study Group

Seattle Children’s Hospital, Seattle, WA, USA

2:18 PM–2:26 PM Discussion

OP-137

2:27 PM–2:31 PM

Are outcomes improving for AIS following FDA HDE approval?

Lawrence L. Haber, Melanie E. Boeyer, Daniel G. ho*rnschemeyer, Samantha C. Ahrens, Julia Todderud, Todd A. Milbrandt, Susan Scariano, Nicole Tweedy, A. Noelle Larson

Ochsner Hospital for Children, New Orleans, LA, USA

OP-138

2:32 PM–2:36 PM

Outcomes in patients with tether rupture after anterior vertebral tethering (AVT) for adolescent idiopathic scoliosis: the good, the bad, and the ugly

John T. Braun, Sofia Federico, David Lawlor, Brian E. Grottkau

Massachusetts General Hospital for Children, Boston, MA, USA

OP-139

2:37 PM–2:41 PM

Complications in vertebral body tethering: what are the effects on patient-reported outcomes?

Katherine Sborov, Mansi Agarwal, Michael J. Heffernan, Jason Anari, Benjamin D. Roye, Stefan Parent, Firoz Miyanji, Selina Poon

Shriners Hospital for Children, Pasadena, CA, USA

2:42 PM–2:50 PM Discussion

OP-140

2:51 PM–2:55 PM

Implementation of the Team Integrated Enhanced Recovery (TIGER) protocol following vertebral body tethering

Daniel G. ho*rnschemeyer, Nicole Tweedy, Melanie E. Boeyer

University of Missouri, Columbia, MO, USA

OP-141

2:56 PM–3:00 PM

Validation study of MR bone-like image for diagnosis of stress fracture (spondylolysis) in the lumbar spine

Yutaka Kinosh*ta, Toshinori Sakai, Kosuke Sugiura, Jiro Kobayashi, Misaki Okita, Koki Moriyama, Shigeki Ueki, Nozomu Yanaida, Koichi Sairyo

Department of Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan

OP-142

3:01 PM–3:05 PM

Treatment and health-related quality of life of acute adolescent spondylolysis: a prospective comparative study with 2-year follow-up

Ella Virkki, Milja Holstila, Terhi Kolari, Markus Lastikka, Sari Inkeri Malmi, Kimmo Mattila, Olli Tapio Pajulo, Ilkka J. Helenius

Turku University Hospital, Turku, Finland

3:06 PM–3:14 PM Discussion

OP-143

3:15 PM–3:19 PM

Spondylolysis, spondylolisthesis, and associated variables in pediatric patients with osteogenesis imperfecta: follow-up from a 2011 study

Garrett Matthew Gloeb, Brian P. Hasley, Maegen Wallace, Hannah Darland

University of Nebraska Medical Center, Omaha, NE, USA

OP-144

3:20 PM–3:24 PM

Is it necessary to extend fusion to L4 when correcting pediatric L5/S1 spondylolisthesis?

Ziming Yao, Xuejun Zhang, Rongxuan Gao, Jiahao Jiao, Dong Guo

Department of Orthopedics, Beijing Children’s Hospital, Capital Medical University, National Center, Beijing China, People’s Republic of China

OP-145

3:25 PM–3:29 PM

Spinal fusion for Scheuermann kyphosis has higher complication and revision rates than spinal fusion for idiopathic scoliosis

Katherine Margaret Krenek, Nicole S. Pham, Marleni Albarran, John Vorhies

Stanford Children’s Health, Palo Alto, CA, USA

3:30 PM–3:38 PM Discussion

SESSION 8B—SPORTS

Room: Cherry Blossom Ballroom

Moderators: Mininder Kocher and Monika Thüsing

2:00 PM–2:02 PM Welcome & Remarks

OP-146

2:03 PM–2:07 PM

Arthroscopic Bankart repair for anterior glenohumeral instability in 488 adolescents between 2000 and 2020: risk factors for subsequent revision stabilization

Jeffrey Kay, Benton E. Heyworth, Donald S. Bae, Mininder S. Kocher, Matthew D. Milewski, Dennis Kramer

Boston Children’s Hospital, Boston, MA, USA

OP-147

2:08 PM–2:12 PM

Length of post-treatment immobilization following medial humeral epicondyle avulsion fracture and return of full range of motion: an interim analysis

Ruth Hendry Jones, Samuel Aaron Beber, Eric W. Edmonds, Benton E. Heyworth, Scott D. McKay, Daryl U.S. Osbahr, Michael Saper, Christopher D. Souder, Matthew D. Ellington, Kevin H. Latz, J. Todd Lawrence, Peter D. Fabricant, Donna M. Pacicca, MEMO Study Group

Hospital for Special Surgery, New York, NY, USA

OP-148

2:13 PM–2:17 PM

Mid-term results of treatment of traumatic knee chondral fractures in adolescents

Alberto Losa Sánchez, Gonzalo Cogolludo Pimentel, Joaquín Nuñez De Armas, Javier Fernandez Jara, Luis Moraleda Novo

Hospital Universitario La Paz, Madrid, Spain

2:18 PM–2:26 PM Discussion

OP-149

2:27 PM–2:31 PM

Patellar lateralization, absence of hyperlaxity, and the mechanism of injury are associated with osteochondral fracture after first-time acute lateral patellar dislocation in adolescents: an MRI-based evaluation

Servet Igrek, Yavuz Sahbat, Erdem Koc, Aytek Huseyin Celiksoz, Mert Osman Topkar, Okan Aslantürk

Kartal Dr. Lütfi Kırdar City Hospital, Istanbul, Turkey

OP-150

2:32 PM–2:36 PM

Number of patellar dislocation events is associated with increased chondral damage of the trochlea: data from the JUPITER group

Joshua Bram, Emilie Lijesen, Daniel W. Green, Matthew William Veerkamp, Bennett Elihu Propp, Danielle Chipman, Benton E. Heyworth, Jacqueline Munch Brady, Beth Shubin Stein, sh*tal N. Parikh, JUPITER Study Group

Hospital for Special Surgery, New York, NY, USA

OP-151

2:37 PM–2:41 PM

Dysplasia worsens over time: trochlear morphologic changes in skeletally immature patients across consecutive magnetic resonance imaging studies

Kevin Jossue Orellana, Julianna Lee, Daniel Yang, David Matthew Kell, Jie C. Nguyen, J. Todd Lawrence, Brendan Williams

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

2:42 PM–2:50 PM Discussion

OP-152

2:51 PM–2:55 PM

The incidence and risk factors for an osteochondral fracture after patellar dislocation

Samir Sharrak, Ali Asma, Marcus A. Shelby, Matthew William Veerkamp, Eric J. Wall, sh*tal N. Parikh

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

OP-153

2:56 PM–3:00 PM

Isolated medial patello-femoral ligament reconstruction with and without bony patellar fixation in young patients - a multicenter comparison of three operative techniques

Brendan Williams, David Matthew Kell, Kevin Jossue Orellana, Morgan Batley, Nathan Chaclas, Alexandra Dejneka, Amin Alayleh, Theodore J. Ganley, Neeraj Patel, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-154

3:01 PM–3:05 PM

Higher rate of redislocation and osteoarthritis after proximal realignment procedures vs MPFL reconstruction: a comparative long-term study of patellar instability in adolescents with open physis with mean 9 years of follow-up

Maija Jääskelä, Marja Susanna Perhomaa, Lasse Lempainen, Jaakko Sinikumpu

Oulu University Hospital, Oulu, Finland

3:06 PM–3:14 PM Discussion

OP-155

3:15 PM–3:19 PM

Suture-based repair with debridement and bone grafting of unstable osteochondritis dissecans of the knee

Crystal Perkins, Anthony Egger, Michael T. Busch, Cliff Willimon

Children’s Healthcare of Atlanta, Atlanta, GA, USA

OP-156

3:20 PM–3:24 PM

Osteochondritis dissecans of the femoral condyle and coronal malalignment: an evaluation of the demographics, incidence, and severity of disease

Claire Clark, Benjamin Johnson, Charles Wyatt, Bayley Nicole Selee, Philip Wilson, Henry Bone Ellis

Scottish Rite for Children, Frisco, TX, USA

OP-157

3:25 PM–3:29 PM

Osteochondral allograft transplantation for capitellar osteochondritis dissecans: excellent patient-reported outcomes scores and high return to sports

Cliff Willimon, Michael T. Busch, Anthony Egger, Erin Yuder, Jason Kim, Shivangi Choudhary, Crystal Perkins

Children’s Healthcare of Atlanta, Atlanta, GA, USA

3:30 PM–3:38 PM Discussion

SESSION 8C – LOWER EXTREMITY & DEFORMITY

Room: National Harbor 2-3

Moderators: Franck Accadbled and Samantha Spencer

2:00 PM–2:02 PM Welcome & Remarks

OP-158

2:03 PM–2:07 PM

Intraarticular deformity after temporary epiphysiodesis around the knee

Bjoern Vogt, Jan Disselkamp, Georg Gosheger, Adrien Frommer, Jan Duedal Rölfing, Gregor Toporowski, Carina Antfang, Robert Roedl, Andrea Laufer

University Hospital Muenster, Muenster, Germany

OP-159

2:08 PM–2:12 PM

Removal of the metaphyseal screw from tension band constructs after angular correction with hemiepiphysiodesis has high rates of physeal tethering and subsequent need for implant removal

Timothy Torrez, Senah Stephens, Emily Zhang, Chris Makarewich

Department of Orthopedics, University of Utah, Salt Lake City, UT, USA

OP-160

2:13 PM–2:17 PM

Accuracy of four different methods for estimation of remaining growth and timing of epiphysiodesis

Anne Berg Breen, Harald Steen, Sanyalak Niratisairak, Are Hugo Pripp, Joachim Horn

Oslo University Hospital, Oslo, Norway

2:18 PM–2:26 PM Discussion

OP-161

2:27 PM–2:31 PM

Does osteotomy level influence consolidation time in tibias treated for limb length discrepancy?

Sandeep Bains, Jeremy Dubin, Larysa Hlukha, John E Herzenberg, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

OP-162

2:32 PM–2:36 PM

Does perioperative ketorolac affect bone healing in pediatric limb lengthening or reconstruction patients?

Christopher A. Iobst, Anirejuoritse Bafor, Danielle Hatfield, Anthony Yassall

Nationwide Children’s Hospital, Columbus, OH, USA

OP-163

2:37 PM–2:41 PM

Evaluation of physical and mental health in adults who underwent limb-lengthening procedures with circular external fixators during childhood or adolescence

Alessandro Depaoli, Marina Magnani, Agnese Casamenti, Marco Ramella, Giovanni Gallone, Gino Rocca, Giovanni Trisolino

IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy

2:42 PM–2:50 PM Discussion

OP-164

2:51 PM–2:55 PM

Infection rates and risk factors with magnetic intramedullary lengthening nails

Jeremy Dubin, Sandeep Bains, Connor James Green, Larysa Hlukha, John E Herzenberg, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

OP-165

2:56 PM–3:00 PM

Are you ready to rumble? Fitbone versus Precise nail smackdown for managing limb length discrepancy

Elizabeth W. Hubbard, Alexander Cherkashin, Mikhail Samchukov, David A Podeszwa, John G Birch

Scottish Rite for Children, Dallas, TX, USA

OP-166

3:01 PM–3:05 PM

Chronic knee pain following infrapatellar/suprapatellar magnetic intramedullary lengthening nails versus external fixators in limb length discrepancy

Larysa Hlukha, Oliver Sax, Kyle Kowalewski, John E Herzenberg, Michael Assayag, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

3:06 PM–3:14 PM Discussion

OP-167

3:15 PM–3:19 PM

Three-dimensional gait analysis and patient-reported outcome measures before and 1 year after femoral derotational osteotomy in adolescents with increased femoral anteversion

Anders Grønseth, Anna Marie Johansson, Terje Terjesen, Joachim Horn

Section for Children’s Orthopedics and Reconstructive Surgery, Division of Orthopedic Surgery, Oslo, Norway

OP-168

3:20 PM–3:24 PM

Correlation of preoperative simultaneous fibular pseudarthrosis with postoperative ankle valgus risk in congenital tibia pseudarthrosis patients

Ge Yang

Hunan Children’s Hospital, Changsha, People’s Republic of China

OP-169

3:25 PM–3:29 PM

Will my child walk funny? The rotational profile of infants and children with classic bladder exstrophy

Maia Regan, Stefano Cardin, Christopher John DeFrancesco, David B Horn

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

3:30 PM–3:38 PM Discussion

SESSION 8D – DEVELOPMENTAL DYSPLASIA OF THE HIP (DDH)

Room: Woodrow Wilson Ballroom

Moderators: Cristina Alves and Kishore Mulpuri

2:00 PM–2:02 PM Welcome & Remarks

OP-170

2:03 PM–2:07 PM

Development and validation of a diagnostic aid for development displacia of the hip

Andreas Roposch, Rachel Buckingham, Claudia Maizen, Pranai Buddhdev, Aresh Hashemi-Nejad

Great Ormond Street Hospital for Children, London, UK

OP-171

2:08 PM–2:12 PM

Spontaneous recovery in the vast majority of stable dysplastic hips

Wesley Theunissen, Maria Christine Van Der Steen, Arnold T Besselaar, Floris Van Douveren, Jaap J Tolk

Máxima Medisch Centrum, Veldhoven, The Netherlands

OP-172

2:13 PM–2:17 PM

Follow-up after successful Pavlik harness treatment for DDH: is 2 years enough?

Jessica Poppy Jane Larwood, Edward Lindisfarne, Kirsten Elliott, Alexander Aarvold

Southampton General Hospital, Southampton, UK

2:18 PM–2:26 PM Discussion

OP-173

2:27 PM–2:31 PM

Comparable amount of residual dysplasia after active surveillance versus abduction brace treatment

Wesley Theunissen, Jaap J Tolk, Arnold T Besselaar, Floris Van Douveren, Maria Christine Van Der Steen

Máxima Medical Center, Veldhoven, The Netherlands

OP-174

2:32 PM–2:36 PM

Influence of standardized hip ultrasound protocol in Pavlik harness during management of developmental hip dislocation

Carlos David Pargas Colina, Todd Blumberg, Caleb Allred, Apeksha Gupta

Seattle Children’s Hospital, Seattle, WA, USA

OP-175

2:37 PM–2:41 PM

Utility of “Pavlik Holiday” for infantile hip dysplasia following failure of Pavlik harness treatment

Maia Shoham, Hiba Naz, Nicole S Pham, Stephanie Pun, Kali Tileston, Meghan N Imrie

Stanford University, Stanford, CA, USA

2:42 PM–2:50 PM Discussion

OP-176

2:51 PM–2:55 PM

Predicting the resolution of residual acetabular dysplasia following successful brace treatment for developmental dysplasia of the hip in infants

Ayesha Saeed, Catharine Bradley, Yashvi Verma, Simon P Kelley

The Hospital for Sick Children (SickKids), Toronto, ON, Canada

OP-177

2:56 PM–3:00 PM

Residual acetabular dysplasia at walking age: a study of 470 hips treated with Pavlik harness

Luckshman Bavan, Thomas Lloyd, Lucy Llewellyn-Stanton, Max Mifsud, Alpesh Kothari

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

OP-178

3:01 PM–3:05 PM

Salter innominate osteotomy for the treatment of developmental dysplasia of the hip in children: Results of 99 consecutive osteotomies after 13–34 years of follow-up

Renee Anne Van Stralen, Ena Colo, Allard Hosman, Wim Willem Schreurs

Radboud UMC, Nijmegen, The Netherlands

3:06 PM–3:14 PM Discussion

OP-179

3:15 PM–3:19 PM

Outcomes following closed reduction for developmental dislocation of the hip

Michele Cerasani, Christina Herrero, Ronald McCartney, Aurelio Alberto Muzaurieta, Pablo Castañeda

NYU Langone Orthopedics, New York, NY, USA

OP-180

3:20 PM–3:24 PM

Closed reduction in developmental dysplasia of hip: predicting acetabular remodeling at skeletal maturity

Evelyn Kuong, Janus Wong, Wang Chow

Hong Kong Children’s Hospital, Hong Kong, Hong Kong

OP-181

3:25 PM–3:29 PM

Acetabular remodeling in developmental dysplasia of the hip: a tri-center analysis of open versus closed reduction in 459 hips

William Zachary Morris, Eduardo Novais, Patricia E Miller, Samantha L Ferraro, Laura M Mayfield, Wudbhav N Sankar

Boston Children’s Hospital, Boston, MA, USA

3:30 PM–3:38 PM Discussion

SESSION 9A – EARLY ONSET SCOLIOSIS (EOS) & MISCELLANEOUS SPINE

Room: Potomac Ballroom

Moderators: Michelle Caird and Ilkka J. Helenius

4:10 PM–4:12 PM Welcome & Remarks

OP-182

4:13 PM–4:17 PM

Reevaluating the role of triradiate cartilage status in shaping curve progression among patients with juvenile idiopathic scoliosis

Hong Zhang, Chan-Hee Jo, Daniel J Sucato

Scottish Rite for Children, Dallas, TX, USA

OP-183

4:18 PM–4:22 PM

Increased thoracic sagittal spine length improves pulmonary function in early-onset scoliosis

Matt Holloway, Todd F Ritzman, Lorena Floccari, Richard Steiner, Jennifer Hurry, Amir Mishreky, Ron El-Hawary, Pediatric Spine Study Group

Akron Children’s Hospital, Akron, OH, USA

OP-184

4:23 PM–4:27 PM

Documenting the variation of proximal foundation constructs and their correlation with unplanned return to the operating room in children with magnetically controlled growing rods

Bahar Shahidi, Fernando Rios, Hazem Elsebaie, Bailee Monjazeb, William Kerr, Joshua Pahys, Steven Hwang, Amer F Samdani, Lindsay Andras, Matthew E Oetgen, Peter O Newton, Burt Yaszay, Peter F Sturm, Michael G Vitale, Paul D Sponseller, Gregory Mundis, Behrooz A Akbarnia, Pediatric Spine Study Group

Pediatric Spine Foundation, Valley Forge, PA, USA

4:28 PM–4:36 PM Discussion

OP-185

4:37 PM–4:41 PM

More screws, more or time, same failure rates: enabling technology use in proximal fixation of growing spine constructs

Daniel Gabriel, Sydney Lee, Shanika De Silva, Daniel Hedequist, Craig Munro Birch, Brian D Snyder, Michael T Hresko, Grant Douglas Hogue

Boston Children’s Hospital, Boston, MA, USA

OP-186

4:42 PM–4:46 PM

The risks and benefits of definitive surgery in the graduation of i-EOS patients whose deformities were managed with GR: a comparison with matched AIS patients

Gokay Dursun, Rafik Ramazanov, Halil Gokhan Demirkiran, Mehmet Ayvaz, Muharrem Yazici

Hacettepe University, Ankara, Turkey

OP-187

4:47 PM–4:51 PM

Lessons learned from 20 years of history using Vertical Expandable Prosthetic Titanium Rib (VEPTR) in Early-Onset Scoliosis patients

Norman Ramirez-Lluch, Alexandra M Claudio-Marcano, John T Smith, John B Emans, Amer F Samdani, Mark A Erickson, John “Jack” M Flynn, Norberto J Torres-Lugo, Gerardo Olivella, Pediatric Spine Study Group

University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico

4:52 PM–5:00 PM Discussion

OP-188

5:01 PM–5:05 PM

Quality of life assessment in early-onset scoliosis: a comparison between the EOSQ-24 and EOSQ-SELF questionnaires on the same patients with two different respondents and time points

Barlas Goker, Gizem Kinikli, Yasemin Yavuz, Rafik Ramazanov, Ataberk Beydemir, Halil Gokhan Demirkiran, Muharrem Yazici

Hacettepe University, Ankara, Turkey

OP-189

5:06 PM–5:10 PM

Utility of preoperative echocardiogram for large curve scoliosis patients

Chidebelum Nnake, Matan Malka, Alondra Concepción-González, Emma Berube, Nicole Bainton, Michael G Vitale, Benjamin D Roye, Joshua E Hyman

Morgan Stanley Children’s Hospital at New York Presbyterian, New York, NY, USA

OP-190

5:11 PM–5:15 PM

Intraoperative CT-based technology significantly increases radiation exposure in the pediatric population

Vishal Sarwahi, Sayyida Hasan, Keshin Visahan, Aravind Patil, Katherine Eigo, Sarah M Trent, Alex Kwong Juen Ngan, Yungtai Lo, Terry D Amaral

Northwell Health, New Hyde Park, NY, USA

5:16 PM–5:24 PM Discussion

OP-191

5:25 PM–5:29 PM

In the era of liposomal bupivacaine: is patient-controlled analgesia even needed?

Ernest Y Young, Ernest Dankwah, Ryan C Goodwin, David P Gurd, Thomas E Kuivila

Cleveland Clinic, Cleveland, OH, USA

OP-192

5:30 PM–5:34 PM

Safety data for robotics coupled with navigation for pediatric spine surgery: initial intraoperative results of a prospective multicenter POSNA-funded registry

Nicole Welch, Alexa Bosco, Jeffrey Michael Henstenburg, Craig Munro Birch, Grant Douglas Hogue, Michael T Hresko, Mark A Erickson, Roger F Widmann, Jessica H Heyer, Kirsten Ross, Robert Francis Murphy, Dennis P Devito, Daniel Hedequist, SPARTAN

Boston Children’s Hospital, Boston, MA, USA

OP-193

5:35 PM–5:39 PM

The impact of lumbar microdiscectomy in adolescents on PROMIS pain, physical function, and mental health domains

Scott J Luhmann, Read Abraham Streller

Washington University School of Medicine, St. Louis, MO, USA

5:40 PM–5:48 PM Discussion

SESSION 9B – ANTERIOR CRUCIATE LIGAMENT (ACL) & MISCELLANEOUS SPORTS

Room: National Harbor 2-3

Moderators: Corinna C. Franklin and Marco Turati

4:10 PM–4:12 PM Welcome & Remarks

OP-194

4:13 PM–4:17 PM

What are the morphological risk factors for pediatric anterior cruciate ligament tears and tibial spine fractures?

Chang-Ho Shin, Akbar Nawaz Syed, Morgan Swanson, Theodore J Ganley, Tibial Spine Research Interest Group

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-195

4:18 PM–4:22 PM

Dynamic point-of-care ultrasound is effective in the early diagnosis of anterior cruciate ligament injuries in children and adolescents

Marcell Benjamin Varga

Manninger Jenő Baleseti Központ, Budapest, Hungary

OP-196

4:23 PM–4:27 PM

Low rates of complications following quadriceps tendon autograft ACL reconstruction in adolescents: strategies for success in the first 12 months

Crystal Perkins, Michael T Busch, Anthony Egger, Jason Kim, Erin Yuder, Shivangi Choudhary, Cliff Willimon

Children’s Healthcare of Atlanta, Atlanta, GA, USA

4:28 PM–4:36 PM Discussion

OP-197

4:37 PM–4:41 PM

Addition of a lateral extra-articular procedure to ACL reconstruction does not increase early complications in pediatric patients

Samuel I Rosenberg, Elizabeth Merritt, Neeraj Patel

Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA

OP-198

4:42 PM–4:46 PM

Risk factors associated with stiffness following pediatric ACL reconstruction: a multicenter study

Jack Beale, Gregory Knell, Robert Yockey, Bobby Van Pelt, Theodore J Ganley, Daniel W Green, Michael Saper, Emily Niu, Matthew Robert Schmitz, Philip Wilson, Henry Bone Ellis, SCORE Quality Improvement Registry

Scottish Rite for Children, Dallas, TX, USA

OP-199

4:47 PM–4:51 PM

Septic arthritis after anterior cruciate ligament reconstruction in pediatric and adolescent vs young adult patients: the 20-year experience at a regional referral center

Deepak Chona, Jeffrey Kay, Ata M Kiapour, Dennis Kramer, Yi-Meng Yen, Melissa A Christino, Matthew D Milewski, Mininder S Kocher, Benton E Heyworth

Boston Children’s Hospital, Boston, MA, USA

4:52 PM–5:00 PM Discussion

OP-200

5:01 PM–5:05 PM

Do children differ from adults in functional limb testing measured at 9 months after ACL reconstruction?

Sarthak Chopra, Pradyumna Raval, Harbeer Ahedi, Alexander Nicholls

Sydney Orthopaedic Research Institute, Sydney, NSW, Australia

OP-201

5:06 PM–5:10 PM

Features of discoid lateral meniscus in pediatric patients with achondroplasia

Jennifer Sheasley, Maya Gopalan, Emily Niu, Apeksha Gupta, Zachary Stinson, Marie-Lyne Nault, Sasha Carsen, Craig Finlayson, R Jay Lee, Brian Michael Haus, Daniel W Green, John A Schlechter, Benton E Heyworth, Jennifer J Beck, Jie C Nguyen, Gregory A Schmale, PRiSM Meniscus Research Interest Group

Seattle Children’s Hospital, Seattle, WA, USA

OP-202

5:11 PM–5:15 PM

MRI-guided retrograde joint-sparing drilling of osteochondritis dissecans of the talus in children

Jyri Järvinen, Mika Hirvonen, Jaakko Sinikumpu, Roberto Blanco Sequeiros

Oulu University Hospital, Oulu, Finland

5:16 PM–5:24 PM Discussion

OP-203

5:25 PM–5:29 PM

Is it worth a shot? Efficacy of a multimodal pain program for pediatric and adolescent knee procedures with and without a single-shot peripheral nerve block

Philip Wilson, James Joseph McGinley, Bobby Van Pelt, Claire Clark, Benjamin Johnson, Charles Wyatt, Henry Bone Ellis

Scottish Rite for Children, Frisco, TX, USA

OP-204

5:30 PM–5:34 PM

To block or not to block? Results from the Society of Pediatric Anesthesia improvement network

Matthew D. Ellington, Steven Staffa, Allison Fernandez, Society Pediatric Anesthesia Interest Network (SPAIN)

Dell Medical School, University of Texas at Austin, Austin, TX, USA

OP-205

5:35 PM–5:39 PM

Single-shot peripheral nerve blocks with Precedex increase neurotoxic complications in pediatric and adolescent arthroscopic knee procedures*

Philip Wilson, James Joseph McGinley, Bobby Van Pelt, Claire Clark, Benjamin Johnson, Charles Wyatt, Henry Bone Ellis

Scottish Rite for Children, Frisco, TX, USA

*Indicates a presentation in which the FDA has not cleared the drug and/or medical device for the use described (i.e. the drug or medical device is being discussed for an “off-label” use.)

5:40 PM–5:48 PM Discussion

SESSION 9C – TRAUMA

Room: Cherry Blossom Ballroom

Moderators: Matthew Oetgen and Annelie–Martina Weinberg

4:10 PM–4:12 PM Welcome & Remarks

OP-206

4:13 PM–4:17 PM

Subaxial cervical spine injury classification system (SLIC) score is useful in guiding treatment decisions in pediatric cervical spine trauma

Tyler Metcalf, Ambika Paulson, Kelly Vittetoe, Katherine Sborov, Teresa Benvenuti, Michael Benvenuti, Kirsten Ross, Jeffrey E Martus, Gregory A Mencio, Jonathan G Schoenecker, Stephanie N Moore-Lotridge, Craig R Louer, Vanderbilt Spine Trauma Consortium

Vanderbilt University Medical Center, Nashville, TN, USA

OP-207

4:18 PM–4:22 PM

Ring the alarm: pediatric patients with operative pelvic ring injuries have similar mortality and morbidity to adults in a national matched cohort study

Amy Steele, David Liu, David Momtaz, Alexander Farid, Jason Young, Leslie C Yuen, Grant Douglas Hogue

Boston Children’s Hospital, Boston, MA, USA

OP-208

4:23 PM–4:27 PM

Etiology and mortality of acute pediatric compartment syndrome: a retrospective review

Olivia Barron, Tristen Taylor, Michael Allison, Madison Harris, Lauren Pupa, Dorothy Harris Beauvais

Baylor College of Medicine, Houston, TX, USA

4:28 PM–4:36 PM Discussion

OP-209

4:37 PM–4:41 PM

The experience of adolescent females following completely displaced midshaft clavicle fractures: sex-specific differences in pain, sensory symptoms, and activities of daily life following surgical treatment

Coleen S Sabatini, Crystal Perkins, Michael Quinn, Rachel Limon Montoya, Eric W Edmonds, Henry Bone Ellis, Andrew Pennock, Cliff Willimon, Philip Wilson, Donald S Bae, Michael T Busch, Mininder S Kocher, Ying Li, Jeffrey Jerome Nepple, Nirav Kiritkumar Pandya, David D Spence, Benton E Heyworth

Boston Children’s Hospital, Boston, MA, USA

OP-210

4:42 PM–4:46 PM

Presence of dorsal spike fragment in conjunction with pediatric volar barton fracture conveys high risk of delayed extensor tendon injury

Ahmad F Bayomy, Charles T Mehlman

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

OP-211

4:47 PM–4:51 PM

Physeal fractures of the distal ulna: incidence and risk factors for premature growth arrest

Pille-Riin Värk, Julianna Lee, Shaun Mendenhall, Benjamin Chang, Eliza Buttrick, Apurva S Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

4:52 PM–5:00 PM Discussion

OP-212

5:01 PM–5:05 PM

“Don’t fear the reamer”: 20-year trends of pediatric femoral fracture fixation show increased utilization of rigid nails in ABOS part II candidates

Kevin Jeffrey Serdahely, Tia Shutes, Craig R Louer, Nathaniel Lempert, Jonathan G Schoenecker, Jeffrey E Martus, David Ebenezer, Gregory A Mencio

Vanderbilt University, Nashville, TN, USA

OP-213

5:06 PM–5:10 PM

How fast and how far? Prospective study on femoral overgrowth in diaphyseal femur fractures

Julia Skye Sanders, Tiffany Phan, Sarah Rose Purtell, Michael J Heffernan, Tyler A Tetreault, Jonas Owen, Lindsay Andras

Children’s Hospital Los Angeles, Los Angeles, CA, USA

OP-214

5:11 PM–5:15 PM

Factors associated with premature physeal closure after distal femur fracture

Andrew Pennock, Liane Chun, Christopher D Souder, Tracey P Bastrom

Rady Children’s Hospital, San Diego, CA, USA

5:16 PM–5:24 PM Discussion

OP-215

5:25 PM–5:29 PM

Do patient-answered versus parent-answered patient-reported outcomes differ in pediatric fracture care?

Tyler McDonald, Cade Smelley

University of South Alabama, Mobile, AL, USA

OP-216

5:30 PM–5:34 PM

Validation of the patient-/parent-reported outcome measure of fracture healing (PROOF-LE) questionnaire for lower-extremity fractures in children

Unni G Narayanan, Sydney Leigh Sharp, Sarah Yang, Stanley Richard Moll, Anne Murphy, Jacqueline Chan, Mark Wickus Camp

The Hospital for Sick Children, Toronto, ON, Canada

OP-217

5:35 PM–5:39 PM

Home management of pediatric buckle fractures: can video education replace an in-person visit?

Mosufa Zainab, Mehmet Esat Kilinc, Evan Sandefur, Andrea Yu-Shan, Nicholas Peterman, Peter J Apel

Virginia Tech Carilion, Roanoke, VI, USA

5:40 PM–5:48 PM Discussion

SESSION 9D – HIP

Room: Woodrow Wilson Ballroom

Moderators: Mihir Thacker and Thomas Wirth

4:10 PM–4:12 PM Welcome & Remarks

OP-218

4:13 PM–4:17 PM

I thought things were too loose? Prevalence and risk factors for stiffness following open reduction for developmental dysplasia of the hip

Vineet Desai, Carter Hall, Stefano Cardin, Wudbhav N Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-219

4:18 PM–4:22 PM

Open reduction of hip dislocations in arthrogryposis is associated with higher rates of AVN than idiopathic DDH: a dual- center study

Tristen Taylor, Rishi Sinha, Callie Bridges, Basel Touban, Nihar Pathare, Caitlin Perez-Stable, Laura M Mayfield, Jaclyn Hill, Scott B Rosenfeld, William Zachary Morris

Texas Children’s Hospital, Houston, TX, USA

OP-220

4:23 PM–4:27 PM

Developmental hip dysplasia: what happens after Pavlik?

Cristina Alves, Carla Sofia Da Silva Carreço, Ines Balaco, Marcos Carvalho, Joao Cabral, Oliana Madeira Tarquini, Pedro Sa Cardoso, Tah Pu Ling

Department of Pediatric Orthopedics, Hospital Pediátrico–CHUC, EPE, Coimbra, Portugal

4:28 PM–4:36 PM Discussion

OP-221

4:37 PM–4:41 PM

The effect of femoral deformity on hip contact mechanics in patients with hip dysplasia: a finite element analysis study

Christian Klemt, Stephanie Kha, Jayme Koltsov, Hiba Naz, Stephanie Pun

Stanford University, Stanford, CA, USA

OP-222

4:42 PM–4:46 PM

Prevalence and radiographic measurements of acetabular dysplasia in over 4000 healthy Dutch adolescents

Suzanne De Vos-Jakobs, Fleur Boel, Delong Chen, Johanna Cornelia Maria Van Haasteren, Rintje Agricola

Erasmus MC–Sophia Children’s Hospital, Rotterdam, The Netherlands

OP-223

4:47 PM–4:51 PM

A biomechanical analysis of the surface contact pressure after an innominate osteotomy for the correction of acetabular dysplasia

Mackenzie A Roof, Gerardo Enrique Sanchez-Navarro, Emmanuel Gibon, Pablo Castañeda

NYU Langone Hassenfeld Children’s Hospital, New York, NY, USA

4:52 PM–5:00 PM Discussion

OP-224

5:01 PM–5:05 PM

Does femoral version impact the patient-reported outcomes and clinical meaningful improvement after periacetabular osteotomy for the treatment of acetabular dysplasia?

Emmanouil (Manos) Grigoriou, Till Lerch, Ani Maroyan, Michael B Millis, Young Jo Kim, Miles Batty, Shanika De Silva, Eduardo Novais

Boston Children’s Hospital, Boston, MA, USA

OP-225

5:06 PM–5:10 PM

Differences in femoro-acetabular impingement morphology on CT between adolescent males and females with symptomatic FAI

Jeffrey Jerome Nepple, Kyle P O’Connor, Robert Westermann, Andrea Spiker, Aaron Krych, Yi-Meng Yen, Christopher Larson, Stephanie Watson Mayer, Matthew Robert Schmitz, Etienne L Belzile, Cecilia Pascual-Garrido, Sasha Carsen, Henry Bone Ellis, Young Jo Kim, John Clohisy, ANCHOR Study Group

Washington University in St. Louis, St. Louis, MO, USA

OP-226

5:11 PM–5:15 PM

A detailed 3D analysis of hip center of rotation trajectory and its effects on impingement-free range of motion: a 3D dynamic analysis of 1222 hips

Ata M Kiapour, Mohammadreza Movahhedi, Mallika Singh, Young Jo Kim, Eduardo Novais

Boston Children’s Hospital, Boston, MA, USA

5:16 PM–5:24 PM Discussion

OP-227

5:25 PM–5:29 PM

Patient-reported outcomes of femoro-acetabular impingement in adolescents with open physes and duration of symptoms: a match-paired analysis

Benjamin Domb, Tyler Robert McCarroll, Andrew Schab, Roger Quesada-Jimenez, Ady Haim Kahana-Rojkind

American Hip Institute Research Foundation, Des Plaines, IL, USA

OP-228

5:30 PM–5:34 PM

Expectations before periacetabular osteotomy and relation to postoperative outcomes and satisfaction

Samantha L Ferraro, Patricia E Miller, Young Jo Kim, Michael B Millis

Boston Children’s Hospital, Boston, MA, USA

OP-229

5:35 PM–5:39 PM

Intraoperative neuromonitoring during periacetabular osteotomy provides actionable alerts: why is it not more widely used?

Lukas G Keil, James David Bomar, V Salil Upasani

Rady Children’s Hospital, San Diego, CA, USA

5:40 PM–5:48 PM Discussion

SESSION 10 – PERTHES & MISCELLANEOUS

Room: Potomac Ballroom

Moderators: Stefan Huhnstock and Harry KW Kim

8:00 AM–8:05 AM Welcome & Remarks

OP-230

8:06 AM–8:10 AM

MRI perfusion correlates with duration of stages and lateral pillar class in Legg-Calvé-Perthes disease

Wudbhav N Sankar, Julianna Lee, David Y Chong, Yasmin D Hailer, Luiz Renato Agrizzi De Angeli, Scott Yang, Jennifer C Laine, Harry KW Kim, International Perthes Study Group

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-231

8:11 AM–8:15 AM

Early-stage femoral head hypoperfusion correlates with femoral head deformity at intermediate-term follow-up in patients with Legg-Calvé-Perthes disease

Michael Seungcheol Kang, David Zimmerhanzel, Shamrez Haider, Harry KW Kim

Scottish Rite for Children, Dallas, TX, USA

OP-232

8:16 AM–8:20 AM

Legg-Calve-Perthes disease: to operate or not to operate!

Joeffroy Otayek, Ayman Assi, Andrea Achkouty, Jerome Sales De Gauzy, Christophe Glorion, Ismat Ghanem

Saint-Joseph University of Beirut, Beirut, Lebanon

8:21 AM–8:29 AM Discussion

OP-233

8:30 AM–8:34 AM

Correlation between radiological parameters and PROMs results in 141 adults who suffered a Perthes disease in childhood: should we modify our approach in the phase of sequelae?

Alberto Losa Sánchez, Luis Moraleda Novo, Joaquín Nuñez De Armas, Ricardo Fernandez Fernandez, Gaspar Gonzalez Moran

Hospital Universitario La Paz, Madrid, Spain

OP-234

8:35 AM–8:39 AM

Predictors of persistent limp following proximal femoral varus osteotomy for Perthes disease

Kevin Jossue Orellana, Joshua Bram, Morgan Batley, Susan A Novotny, Hitesh Shah, Derek M Kelly, Benjamin D Martin, Tim Schrader, Jennifer C Laine, Harry KW Kim, Wudbhav N Sankar, International Perthes Study Group

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

OP-235

8:40 AM–8:44 AM

Comparison of mid- to long-term outcomes of conservative treatment versus shelf acetabuloplasty in Perthes disease

Mehmet Demirel, Ilhan Sulejmani, Yasar Samet Gökçeoglu, Yavuz Saglam, Fuat Bilgili

İstanbul School of Medicine, Istanbul University, Istanbul, Turkey

8:45 AM–8:53 AM Discussion

OP-236

8:54 AM–8:59 AM

Improved gait and patient-reported outcomes following hip preservation procedures via surgical hip dislocation in adolescents with residual Legg-Calve-Perthes disease

Kanav Chhabra, Nicholas Anable, Arnav Kak, Chan-Hee Jo, John Anthony “Tony” Herring, Daniel J Sucato, Harry KW Kim

Scottish Rite for Children, Dallas, TX, USA

OP-237

9:00 AM–9:04 AM

Development of a minimally invasive piglet model of Legg-Calve-Perthes disease

Susan A Novotny, Reza Talaie, Erick Buko, Ashton Adele Amann, Alexandra Armstrong, Casey P Johnson, Ferenc Toth, Jennifer C Laine

Gillette Children’s Specialty Healthcare, St. Paul, MN, USA

OP-238

9:05 AM–9:09 AM

Two novel tissue types identified in 3D morphometric analyses of Perthes hips: is this the key to early prognostic modeling?

Hannah Kane, Siobhan Hoare, Thomas Brendan Murphy, Niamh Nowlan, Connor James Green

University College Dublin, Dublin, Ireland

9:10 AM–9:18 AM Discussion

SESSION 11 – TRAUMA

Room: Potomac Ballroom

Moderators: Federico Canavese and Kenneth Noonan

OP-239

10:15 AM–10:19 AM

Vitamin D—a risk factor for bone fractures in children: a population-based prospective case-control randomized cross-sectional study

Alexandru-Dan Herdea, Alexandru Ulici

University of Medicine and Pharmacy “Carol Davila”, Bucharest, Romania

OP-240

10:20 AM–10:24 AM

Time to closed reduction in the ED: who is at risk for delays, and does it matter?

Ryan Sadjadi, Avionna Baldwin, Daniel Soroudi, Ishaan Swarup

UCSF Benioff Children’s Hospital, Oakland, CA, USA

OP-241

10:25 AM–10:29 AM

Nonoperative vs. operative management of type I pediatric open fractures

Jeremy Dubin, Sandeep Bains, Daniel Hameed, Mallory C Moore, John E Herzenberg, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

10:30 AM–10:38 AM Discussion

OP-242

10:39 AM–10:43 AM

Gartland type IIB supracondylar fractures can be treated using Blount’s method

Kätlin Puksand, Petra Grahn, Matti Mikael Ahonen, Juho-Antti Ahola, Topi Aaretti Laaksonen

Helsinki University Hospital, Helsinki, Finland

OP-243

10:44 AM–10:48 AM

Does time to surgery impact nerve recovery in supracondylar humerus fractures with nerve injury?

Brian Wahlig, Mikaela Sullivan, Samuel Broida, A Noelle Larson, William J Shaughnessy, Anthony A Stans, Emmanouil (Manos) Grigoriou, Todd A Milbrandt

Mayo Clinic, Rochester, MN, USA

OP-244

10:49 AM–10:53 AM

Epidemiology of operatively treated pediatric medial epicondyle fractures

Akbar Nawaz Syed, Joseph Yellin, Divya Talwar, Margaret Bowen, Leta Ashebo, Scott D McKay, Peter D Fabricant, Eric W Edmonds, Benton E Heyworth, Michael Saper, Donna M Pacicca, Kevin H Latz, Stephanie Watson Mayer, Daryl US Osbahr, Christopher D Souder, J Todd Lawrence, Medial Epicondyle Multicenter Outcomes

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

10:54 AM–11:02 AM Discussion

OP-245

11:03 AM–11:07 AM

Enhancing tibial spine fracture repair: suture plus diaphyseal suture anchors biomechanically outperform sutures and screws in pediatric cadaveric knees

Thomas M Johnstone, Ian Hollyer, Kelly Heavner McFarlane, Amin Alayleh, Calvin Chan, Seth Sherman, Kevin G Shea

Stanford University, Stanford, CA, USA

OP-246

11:08 AM–11:12 AM

Risk factors for combined tibial tubercle avulsion fracture and patellar tendon tears

Rebecca Schultz, Basel Touban, Jason Amaral, Raymond Kitziger, Tiffany Lee, Matthew Parham, Scott D McKay

Texas Children’s Hospital, Houston, TX, USA

OP-247

11:13 AM–11:17 AM

Risk factors for the development of premature physeal closure after a McFarland fracture in children

Yuancheng Pan, Federico Canavese, Shunyou Chen

Fuzhou Second Hospital, Fuzhou, People’s Republic of China

11:18 AM–11:26 AM Discussion

OP-248

11:27 AM–11:31 AM

Prospective distal tibial physeal fractures: short leg vs. long leg casting

Brock Todd Kitchen, Eric W Edmonds, V Salil Upasani, Christopher D Souder, James David Bomar, Macy Dexter, Andrew Pennock

Rady Children’s Hospital, San Diego, CA, USA

OP-249

11:32 AM–11:36 AM

Remodeling potential after distal tibial physeal fractures

Christopher D. Souder, James David Bomar, Christine Ho, Brian P. Scannell

Rady Children’s Hospital, San Diego, CA, USA

OP-250

11:37 AM–11:41 AM

Identification of and response to growth arrest following pediatric ankle fractures

Charles T Mehlman, Jaime Rice Denning, sh*tal N Parikh, Junichi Tamai, Dayna Phillips

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

11:42 AM–11:50 AM Discussion

11:51 AM–12:00 PM Closing Remarks

BASIC SCIENCE

e-Poster 1

Alterations in the bone collagen organization in osteogenesis imperfecta

Wouter H Nijhuis, Zhiming Wu, Stefan Smit, Kelly Warmink, Harrie Weinans, Ruud Bank, Ralph JB Sakkers

University Medical Center Utrecht, Utrecht, The Netherlands

e-Poster 2

Changes around knee after apophysiodesis of tibial apophysis in rats (preliminary results)

Emre Cullu, Figen Sevil Kilimci, Mehmet Erkut Kara, Firuze Türker Yavas

Adnan Menderes University, Aydın, Turkey

e-Poster 3

Circ_0000888 regulates osteogenic differentiation of periosteal mesenchymal stem cells in congenital pseudarthrosis of the tibia

Ge Yang

Hunan Children’s Hospital, Changsha, Hunan, People’s Republic of China

e-Poster 4

Guided growth for trochlear dysplasia: development of a rabbit model

Marcus A Shelby, Carolyn Doerning, John Miras Racadio, Matthew William Veerkamp, Savannah Walters, Ross Schierling, Angie Cummins, sh*tal N Parikh

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

e-Poster 5

Hip dysplasia in mucopolysaccharidosis type 1 Hurler: midterm radiological and functional outcomes after hematopoietic stem cell-gene therapy

Maurizio De Pellegrin, Chiara Filisetti, Matilde Cossutta, Barbara Guerrini, Renata Mellone, Giulia Consiglieri, Francesca Tucci, Marina Sarzana, Alessandro Aiuti, Maria Ester Bernardo, SR-Tiget MPSIH

San Raffaele Telethon Institute for Gene Therapy (SR-TIGET), Milan, Italy

e-Poster 6

Quantitative MRI may help detect bone repair in a piglet model of Legg-Calvé-Perthes disease

Ashton Adele Amann, Erick Buko, Alexandra Armstrong, Jennifer C Laine, Susan A Novotny, Reza Talaie, Ferenc Toth, Casey P Johnson

Gillette Children’s Specialty Healthcare, St. Paul, MN, USA

e-Poster 7

Sulfur biology may be key to the aetiology of developmental dysplasia of the hip

Amanda ML Rhodes, Sehrish Ali, Magdalena Minnion, Ling Hong Lee, Brijil Maria Joseph, Judwin Alieh Ndzo, Nicholas MP Clarke, Martin Feelisch, Alexander Aarvold

Southampton Children’s Hospital, Southampton, UK

CONGENITAL, SYNDROMIC, AND SKELETAL DYSPLASIAS

e-Poster 8

Characterization of bone growth patterns across the lifespan of individuals with osteogenesis imperfecta

Matthew Bernhard, Chloe Derocher, Erin Carter, Karl John Jepsen, Cathleen L Raggio

Hospital for Special Surgery, New York, NY, USA

e-Poster 9

Therapeutic effect of intramedullary reaming and nailing for long bones lengthening in children with Ollier disease and Maffucci syndrome on enchondromas: retrospective series

Samuel Georges, Bonneau Soline, Bernard Fraisse, Bremond Nicolas, Yan Lefèvre, Philippe Violas, Zagorka Pejin

Pediatric Orthopedic and Traumatology Department, Necker University Hospital, Paris, France

e-Poster 10

To stand or not to stand: a retrospective review of clinical and health-related quality of life outcomes related to supported standing in patients with MMFC1 spina bifida

Peter C Shen, Jill E Larson

Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA

FOOT & ANKLE

e-Poster 11

Does clubfoot affect sports performance?

Michelle Mo, Megan M Hannon, William Meehan, Patricia E Miller, Matthew Lincoln Rauseo, Shawn Patrick Cameron, Maya Fajardo, Susan T Mahan

Boston Children’s Hospital, Boston, MA, USA

e-Poster 12

Pedobarography and ankle-foot kinematics in children with symptomatic flexible flatfoot after medializing calcaneal osteotomy: a cross-sectional study

Noppachart Limpaphayom

Chulalongkorn University, Bangkok, Thailand

e-Poster 13

Sports participation reported in children and adolescents after treatment for idiopathic clubfoot using Ponseti method

James Weihe, Abigail Padilla, Divya Jain, Shannon Margherio, Melissa Bent, Natalie C Stork

Children’s Hospital Los Angeles, Los Angeles, CA, USA

e-Poster 14

Surgical considerations for children with foot syndactyly

Eliza Buttrick, Sulagna Sarkar, Amanda Pang, Austin James Reiner, Christina Michelle Sacca, Christine Goodbody, David B Horn, Shaun Mendenhall, Apurva S Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

HAND/UPPER EXTREMITY

e-Poster 15

Clinical presentation and patient-reported function in children with Sprengel’s deformity

Julianna Lee, Eliza Buttrick, Carley Vuillermin, Lindley B Wall, Julie Samora, Apurva S Shah, CoULD Study Group

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 16

Lengthening over the plate in forearm deformity - a novel technique to reduce the duration of external fixation and related complications

Kyeong-Hyeon Park, Chang Wug-Oh

Severance Children’s Hospital, Seoul, Republic of Korea

e-Poster 17

Pediatric radial head ossification patterns

Tiffany Liu, Hannah May Reen Chi, Arin Kim, Bamidele Kammen, Ishaan Swarup

UCSF Benioff Children’s Hospital, Oakland, CA, USA

e-Poster 18

Reachable workspace by injury level in brachial plexus birth injury

Stephanie Russo, Tyler Richardson, Emily Nice, Spencer Warshauer, Dan Ariel Zlotolow, Scott H Kozin

Shriners Children’s Philadelphia, Philadelphia, PA, USA

e-Poster 19

Recreational-therapeutic workshops for the use of myoelectric prostheses in upper-limb agenesis

Sergio Martinez Alvarez, Álvaro Pérez-Somarriba, Paula Serrano Gonzalez, María Galán Olleros, Íñigo Monzón Tobalina, Isabel Vara Patudo, Maria Teresa Vara, Angel Palazon Quevedo

Hospital Infantil Universitario Niño Jesús, Madrid, Spain

e-Poster 20

Throwing pains: clinical presentation and surgical outcomes of cubital tunnel syndrome in children and adolescents

Nathan Chaclas, Scott J Mahon, Joseph Yellin, Christine Goodbody, Apurva S Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

HIP

e-Poster 21

A hybrid virtual baby hip clinic improves care for the nonoperative treatment of developmental dysplasia of the hip

Yashvi Verma, Kylie Maxwell, Catharine Bradley, Simon P Kelley

The Hospital for Sick Children (SickKids), Toronto, ON, Canada

e-Poster 22

A novel low-cost acoustic screening method for early detection of developmental dysplasia of the hip in infants

Yealeen Jeong, Taylor A Jazrawi, Hansen A Mansy, Richard H Sandler, Charles T Price, Pablo Castañeda

NYU Langone Hassenfeld Children’s Hospital, New York, NY, USA

e-Poster 23

Acetabular changes in 80 surgically treated perthes patients, from diagnosis to healing

Yasmin D Hailer, Wiktor Mizgalewicz, Hitesh Shah

Kasturba Hospital, Manipal, India

e-Poster 24 (Nominated for Best ePoster)

Acetabular teardrop ratio, a novel radiographic measurement in developmental dysplasia of the hip

Joanne Abby Marasigan, Munish Krishnan, Kurt Seagrave, David Graham Little

Children’s Hospital at Westmead, Westmead, NSW, Australia

e-Poster 25

Anteroinferior iliac spine osteoplasty at the time of periacetabular osteotomy helps preserve preoperative range of motion

Wasim Shihab, Connor Luck, Jonathan Dalton, Ashley Disantis, Jennifer Oakley, Michael McClincy

UPMC Children Hospital, Pittsburgh, PA, USA

e-Poster 26

Birthweight correlates to pubo-femoral distances and alpha angles in hip ultrasound of newborns at 6 weeks of age

Maria Tirta, Ole Rahbek, Michel Bach Hellfritzsch, Rikke Damkjær Maimburg, Mads Henriksen, Søren Kold, Natalia Lapitskaya, Bjarne Moeller-Madsen, Hans-Christen Husum

Interdisciplinary Orthopedics, Aalborg University Hospital, Aalborg, Denmark

e-Poster 27

Combined guided growth and growth tethering versus varus osteotomy for caput valgum and leg length discrepancy following surgery in developmental dysplasia of the hip: outcome of the hip development

Kuan-wen Wu, Chia-Che Lee, Ting-ming Wang, Ken N Kuo

Department of Orthopedic Surgery, National Taiwan University Hospital, Taipei

e-Poster 28

Femoral anteversion assessment: 3D modelization insight

Mohamed Laroussi Toumia, Alina Badina, Nejib Khouri, Axel Koussou, Eric Desailly

Necker University Hospital, APHP, Paris, France

e-Poster 29

How long is a piece of string? Duration of Pavlik harness treatment for developmental dysplasia of the hip

Bhushan Sharad Sagade, Junior Consultant, Kakra Wartemberg, Julia Judd, Safwan Abdulwahid, Edward Lindisfarne, Kirsten Elliott, Alexander Aarvold

University Hospital Southampton, Southampton, UK

e-Poster 30

Impact of Pavlik harness treatment on motor skills acquisition: a prospective study

Ana Rita Jesus, Catarina Silva, Inês Luz, José Eduardo Mendes, Ines Balaco, Cristina Alves

Department of Pediatric Orthopedics, Hospital Pediátrico–CHUC, EPE, Coimbra, Portugal

e-Poster 31 Withdrawn

e-Poster 32

Natural evolution of Legg-Calvé-Perthes disease in children “surgical hips” treated with a nonoperative approach

Joeffroy Otayek, Ayman Assi, Andrea Achkouty, Jerome Sales De Gauzy, Christophe Glorion, Ismat Ghanem

Saint-Joseph University of Beirut, Beirut, Lebanon

e-Poster 33

One-third of patients with slipped capital femoral epiphysis have abnormal thyroid screening studies

Ena Nielsen, Braeden Makato Leiby, Todd Blumberg

Seattle Children’s Hospital, Seattle, WA, USA

e-Poster 34 (Nominated for Best ePoster)

Optimizing the arthrogram: does local anesthetic improve the duration of femoral head visualization?

Kyle Maas, Nicholas Chiaramonti, Ira Zaltz, Alex Gornitzky

University of Michigan, Ann Arbor, MI, USA

e-Poster 35

Osteochondral allograft transplantation for large chondral lesions of the femoral head in young patients

V Salil Upasani, Omid Jalali, James David Bomar, Lei Zhao, Patrick William Whitlock, Jordan K Penn, Julie McCauley, William Bugbee, Andrew Pennock

Rady Children’s Hospital, San Diego, CA, USA

e-Poster 36

Outcomes of hip arthroscopy with concomitant periacetabular osteotomy: minimum 5-year follow-up

Ady Haim Kahana-Rojkind, Ali Parsa, Saiswarnesh Padmanabhan, Rachel Bruning, Tyler McCarroll, Justin Mark Lareau, Benjamin Domb

American Hip Institute Research Foundation, Des Plaines, IL, USA

e-Poster 37

Outcomes of treatment of pediatric pathologic femoral neck fractures

Rishi Sinha, Shamrez Haider, Chinelo Onubogu, Alexandra Callan, David A Podeszwa, William Zachary Morris

Scottish Rite for Children, Dallas, TX, USA

e-Poster 38

Patients with CMT undergoing a Bernese PAO return to baseline gait parameters and improve patient-reported outcomes at 2 years but are worse than normal controls

Andrew Hinkle, Nicholas Anable, Lauren Osborne, David A Podeszwa, William Zachary Morris, Daniel J Sucato

Scottish Rite for Children, Dallas, TX, USA

e-Poster 39

Perthes disease. Ellipsoidal process: is it possible to prevent the deformity?

Margarita Montero Diaz, Juan Carlos Abril

Ruber International Hospital, Madrid, Spain

e-Poster 40

Postoperative cast immobilization might be unnecessary after pelvic osteotomy for children with developmental dysplasia of the hip: a systematic review

Mohamed Mai, Renee Anne Van Stralen, Sophie Moerman, Christiaan JA Van Bergen

Force Amphia, Breda, The Netherlands

e-Poster 41

Preoperative gallows traction as an adjunct to hip open reduction surgery: is it safe and is it effective?

Nicholas Uren, Alexander Aarvold, Julia Judd, Kirsten Elliott, Stephanie Jane Buchan, Edward Lindisfarne

Southampton Children’s Hospital, Southampton, UK

e-Poster 42

Radiation burden and associated cancer risk amongst children undergoing open reduction for developmental dysplasia of the hip (DDH)

Waseem Hasan, Nicholas Uren, Alexander Aarvold

Southampton General Hospital, Southampton, UK

e-Poster 43

Re-analyses of treatment outcomes and prognostic factors of a large prospective multicenter study of Legg-Calvé-Perthes disease using the sphericity deviation score

Michael Seungcheol Kang, Arnav Kak, Lauren Osborne, John Anthony “Tony” Herring, Harry KW Kim

Scottish Rite Hospital, Dallas, TX, USA

e-Poster 44 (Nominated for Best ePoster)

Relationship of self-reported pain, degree of hip dysplasia, and behavioral health diagnosis in adolescents and young adults

Heather M Richard, Daryn Strub, Kirsten Tulchin-Francis, Craig Smith, Kevin E Klingele

Nationwide Children’s Hospital, Columbus, OH, USA

e-Poster 45

Shenton’s line in DDH: useful or useless?

Jessica Poppy Jane Larwood, Richard Connell, Waseem Hasan, Alexander Aarvold

Southampton General Hospital, Southampton, UK

e-Poster 46

The anterior modified San Diego acetabuloplasty does not result in improved anterior acetabular coverage

Joshua Carroll Tadlock, Garrett E Rupp, Christine L Farnsworth, James David Bomar, Jason Patrick Caffrey, V Salil Upasani

Rady Children’s Hospital, San Diego, CA, USA

e-Poster 47

The detrimental effect of human growth hormone treatment on the development of slipped capital femoral epiphysis

Mehul Mittal, David Momtaz, Rishi Gonuguntla, Mahshid Mohseni, Beltran Torres-Izquierdo, Aaron Singh, Pooya Hosseinzadeh

Washington University School of Medicine, St. Louis, MO, USA

e-Poster 48

The sphericity deviation score, a continuous parameter to assess femoral head sphericity in Legg-Calvé-Perthes disease: is it useful and reliable?

Chiara Blatti, Jennifer C. Laine, Anders Wensaas, Sahar Toumie, Armend Fejzulai, Stefan Huhnstock

Oslo University Hospital, Oslo, Norway

e-Poster 49

Trans-perineal hip ultrasound in developmental dysplasia of the hip patients treated with Pavlik harness and Tübingen hip flexion splint

Xuemin Lyu, Zheng Yang

Beijing Jishuitan Hospital, Beijing, People’s Republic of China

e-Poster 50

Treatment outcomes at skeletal maturity after physeal-sparing procedure for early onset slipped capital femoral epiphysis

Mi Hyun Song, Chang-Ho Shin, Tae-Joon Cho

Seoul National University Children’s Hospital, Seoul, Republic of Korea

e-Poster 51

Ultrasound and magnetic resonance in spica cast for detection of femoral head reduction in unstable developmental dysplasia of the hip

Nicola Guindani, Luca Grion, Jole Graci, Federico Chiodini

Papa Giovanni XXIII Hospital, Bergamo, Italy

e-Poster 52

Upper retinacular vascular avulsion: a newly described cause of avascularity of the femoral epiphysis in unstable slipped capital femoral epiphysis

Katherine Sara Hajdu, David Ebenezer, Nathaniel Lempert, Craig R. Louer, Stephanie N. Moore-Lotridge, Courtney Baker, Jonathan G. Schoenecker

Vanderbilt University Medical Center, Nashville, TN, USA

INFECTION AND TUMOR

e-Poster 53

Clavicular osteomyelitis in children: special considerations for the orthopedic surgeon

Jessica Davis Burns

Phoenix Children’s Hospital, Phoenix, AZ, USA

e-Poster 54 (Nominated for Best e-Poster)

Does rickets carry an increased risk of osteomyelitis and septic arthritis? a large database study

Monish Sai Lavu, Chloe Heather Van Dorn, Lukas Bobak, Robert John Burkhart, David Kaelber, R. Justin Mistovich

University Hospitals Rainbow Babies and Children’s Hospital, Cleveland, OH, USA

e-Poster 55

Is exclusive oral antibiotic treatment feasible in pediatric uncomplicated osteomyelitis?

Cindy Mallet, Anne-Laure Simon, Brice Ilharreborde

Robert Debre Hospital, Paris, France

e-Poster 56

It is as easy as complete blood cell (with a Diff): using the neutrophil-to-lymphocyte-to-platelet ratio to determine the severity of pediatric musculoskeletal infection

Brian Quincey Hou, Malini Anand, William Franklin Hefley, Katherine Sara Hajdu, Stephen Chenard, Anoop Chandrashekar, Naadir Jamal, Michael Joseph Greenberg, Courtney Baker, Keith D. Baldwin, Stephanie N. Moore-Lotridge, Jonathan G. Schoenecker

Vanderbilt University Medical Center, Nashville, TN, USA

e-Poster 57

Knee septic arthritis or Lyme disease: can it be predicted?

Ying Li, Ryan Sanborn, Danielle Cook, Keith D. Baldwin, Benjamin J. Shore, Children’s Orthopaedic Trauma and Infection Consortium for Evidence-Based Studies (CORTICES)

University of Michigan, Ann Arbor, MI, USA

e-Poster 58

Neurodivergent patients are at increased risk of infection after orthopedic surgery: a multicenter cohort study across 25 years

Janus Wong, Lauren Sun, Alfred Lee, Noah So, Evelyn Kuong, Michael To, Wang Chow

The University of Hong Kong, Hong Kong, Hong Kong

e-Poster 59

Pathologic fractures in patients with neuroblastoma impacts overall survival

David Matthew Kell, Sulagna Sarkar, Akbar Nawaz Syed, Ryan Guzek, Jie C. Nguyen, Alexandre Arkader

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 60

Peroneal nerve decompression in pediatric patients with multiple hereditary exostoses

Aaron Huser, Hans K. Nugraha, Arun R. Hariharan, David S. Feldman

Paley Orthopedic & Spine Institute, West Palm Beach, FL, USA

e-Poster 61 Withdrawn

e-Poster 62

Resident-performed bedside aspiration for workup of the pediatric septic hip: expedited diagnosis, no decrease in time to definitive treatment

Kira Skaggs, Olivia Okoli, Hiba Naz, Nicole S. Pham, John Vorhies, Kali Tileston

Stanford University, Palo Alto, CA, USA

e-Poster 63 (Nominated for Best e-Poster)

Separate resection of biopsy tract and primary sarcoma: implications for local recurrence and overall survival

Michael D. Eckhoff, Thomas J. Utset-Ward, Daryn Strub, Kirsten Tulchin-Francis, Thomas J. Scharschmidt

Nationwide Children’s Hospital, Columbus, OH, USA

e-Poster 64

Single-stage surgical debridement with and without local application of vancomycin-loaded calcium sulphate for treatment of chronic osteomyelitis in children: a comparative study

Ahmed Hamed Kassem Abdelaal

Sohag University, Sohag, Egypt

e-Poster 65

Treatment of aneurysmal bone cysts in children and risk factors for fractures and complications: a multicenter study

Ali Erkan Yenigül, Mahmut Kursat Ozsahin, Osman Emre Aycan, Ömer Sofulu, Bahattin Kerem Aydin, Ahmet Nadir Aydemir, Sahin Cepni, Bulent Erol, Cenk Ermutlu, Bartu Sarisozen, Turkish Society of Children’s Orthopedics Tumour Study Group

Marmara University, Istanbul, Turkey

LOWER EXTREMITY/DEFORMITY

e-Poster 66 Withdrawn

e-Poster 67

A novel plate design for rotational guided growth: an experimental study in immature porcine femurs

Ahmed Halloum, Maria Tirta, Søren Kold, Jan Duedal Rölfing, Ahmed Abdul-Hussein Abood, Shima Gholinezhad, Ali Yalcinkaya, Ole Rahbek

Aalborg University Hospital, Aalborg, Denmark

e-Poster 68 (Nominated for Best e-Poster)

Assessing the accuracy of predictive models in angular deformity

Brian C. Lynch, Robert K. Lark, Robert Fitch

Duke University, Durham, NC, USA

e-Poster 69

Comparing relative value units for intramedullary limb lengthening procedures to common pediatric orthopedic surgeries to determine adequate compensation

Jill C. Flanagan, Sonia Gilani, Anirejuoritse Bafor, Christopher A. Iobst

Children’s Healthcare of Atlanta, Atlanta, GA, USA

e-Poster 70

Decision-making in congenital femoral deficiency: a stated preference survey of patients, parents, and clinicians

Ilene Hollin, Sarah Beth Nossov, Corinna C. Franklin, Henrike Schmalfuss, Camille Brown, Malliena DeShields, Kyrillos Akhnoukh

Shriners Children’s™ Philadelphia, Philadelphia, PA, USA

e-Poster 71

Does percentage of canal reaming prior to insertion of motorized intramedullary nails influence consolidation time in limb length discrepancy corrections?

John E. Herzenberg, Philip McClure, Larysa Hlukha, Sandeep Bains

International Center for Limb Lengthening, Baltimore, MD, USA

e-Poster 72

Hemi-epiphysiodesis correction rates for lower extremity malalignment are similar between multiple hereditary exostoses and idiopathic populations

Joshua Bram, Don Tianmu Li, Olivia Christina Tracey, Emilie Lijesen, Danielle Chipman, Roger F. Widmann, Emily Dodwell, John S. Blanco, Daniel W. Green

Hospital for Special Surgery, New York, NY, USA

e-Poster 73 (Nominated for Best e-Poster)

Infantile Blount disease and overweight in Ghana

Niels Jansen, Heleen Staal

Maastricht UMC+, Maastricht, The Netherlands

e-Poster 74 (Nominated for Best e-Poster)

International field test of LIMB-Q Kids: a new patient-reported outcome measure for lower limb differences

Harpreet Chhina, Anne Klassen, Jan Duedal Rölfing, Bjoern Vogt, Mohan V. Belthur, Alicia Kerrigan, Marcel Abouassaly, Jonathan Wright, Ashish Ranade, Louise Johnson, David A. Podeszwa, James Alfred Fernandes, Juergen Messner, Christopher A. Iobst, Sanjeev Sabharwal, Anthony Philip Cooper, LIMB-Q Kids Study Group

University of British Columbia, Vancouver, BC, Canada

e-Poster 75

Limb reconstruction in severe tibial hemimelia: minimum 4-year follow-up

Aaron Huser, David S. Feldman, Claire Elizabeth Shannon, Katherine Miller, Dror Paley

Paley Orthopedic & Spine Institute, West Palm Beach, FL, USA

e-Poster 76

Magnetic intramedullary lengthening nails can be lengthened to their maximum with no increase in nail failure

Jeremy Dubin, Sandeep Bains, Daniel Hameed, John E. Herzenberg, Michael Assayag, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

e-Poster 77

Patients with lower limb deficiencies mobilizing with extension-prosthesis: long-term follow-up, quality of life, and function

Sharon Eylon, Raafat Akil, Patrice L. (Tamar) Weiss, Vladimir Goldman

Alyn Rehabilitation hospital for Children & Adolescents, Jerusalem, Israel

e-Poster 78

Re-use of motorized intramedullary limb lengthening nails*

Andrew Gregory Georgiadis, Nickolas Nahm, Mark T. Dahl

Gillette Children’s, St. Paul, MN, USA

*Indicates a presentation in which the FDA has not cleared the drug and/or medical device for the use described (i.e., the drug or medical device is being discussed for an “off label” use).”

e-Poster 79

Unrecognized consequences of growth modulation: are we prioritizing limb alignment over future joint health?

Taylor Zak, Elizabeth W. Hubbard, Anthony Minopoli, Claire Shivers, David A. Podeszwa

Scottish Rite for Children, Dallas, TX, USA

NEUROMUSCULAR

e-Poster 80 Withdrawn

e-Poster 81

Clinical, densitometric, and laboratory evaluation of bones in children with neuro-orthopedic diseases resulting in motor disability

Wojciech Stelmach, Kryspin Niedzielski, Krzysztof Malecki, Pawel Flont, Kornelia Pruchnik Witoslawska

Polish Mother’s Memorial Hospital Research institute, Łódź, Poland

e-Poster 82 (Nominated for Best e-Poster)

Incidence of femur fracture post hardware removal in children with cerebral palsy who have undergone varus derotational osteotomy

Ellie Montufar Wright, Luiz Carlos Almeida Da Silva, Jason Howard, Sarah Raab, Kenneth Rogers, Amelia M. Lindgren, Freeman Miller, Arianna Trionfo, M. Wade Shrader

Nemours Children’s Hospital, Wilmington, DE, USA

e-Poster 83

Medium-term outcomes after multi-level surgery in children with bilateral cerebral palsy

Ken Ye, Ayman D’Souza, Rebecca Morgan, Alpesh Kothari

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

e-Poster 84

One injection of Botulinum toxin A in biceps brachii in cerebral palsy has both a degenerative and regenerative effect

Eva M. Ponten, Ferdinand Von Walden, Alexandra Palmcrantz, Per Stal

Karolinska Institutet, Stockholm, Sweden

e-Poster 85

Recurrence of spastic planovalgus foot in cerebral palsy: a comprehensive study on influencing factors

Ana Laura Arenas Diaz, Carlos Alfonso Guzmán-Martín, Thania Ordaz, Agustin Barajas Monterrey, Andrea Gabriela García Rueda, Erika Barron Torres, Clemente Hernández, Javier Masquijo

Shriners Children’s™ Mexico, Mexico City, Mexico

e-Poster 86

Rotation and asymmetry of the axial plane pelvis in cerebral palsy: a computed tomography–based study

Akbar Nawaz Syed, Jenny Liu Zheng, Christine Goodbody, Patrick John Cahill, David A. Spiegel, Keith D. Baldwin

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 87

Talo-calcaneal-navicular realignment surgery in severe neurologic equinovarus foot: mid-term results of a novel surgical approach

María Galán Olleros, María Jesus Figueroa, Ana Ramirez Barragan, Gonzalo Andres Chorbadjian Alonso, Manuel Fraga, Ignacio Martinez Caballero

Hospital Infantil Universitario Niño Jesús, Madrid, Spain

e-Poster 88

Worsening gait deviations in hereditary spastic paraparesis

Lizabeth Bunkell, Cinthya Meza, Kelly Jeans, Linsley B. Smith, Michelle Christie, Fabiola Reyes, Robert Lane Wimberly

Scottish Rite for Children, Dallas, TX, USA

QUALITY, SAFETY, VALUE INITIATIVES; ARTIFICIAL INTELLIGENCE; MACHINE LEARNING; AND MISCELLANEOUS

e-Poster 89

Cost analysis and variability in pediatric anterior cruciate ligament reconstruction: insights for optimizing surgical value

Emily Moya, Kelly Heavner McFarlane, Kali Tileston, Charles M. Chan, Kevin G. Shea

Stanford University, Palo Alto, CA, USA

e-Poster 90

Efficacy of DIY cast covers: an in vivo study

John A. Schlechter, Amirhossein Misaghi, Remy Zimmerman, Gian Ignacio, Hayley Ditmars

Riverside University Health Systems, Moreno Valley, CA, USA

e-Poster 91

Embracing wide awake techniques in pediatric orthopedic surgery

Sonia Chaudhry, Lisa Tamburini

Connecticut Children’s Medical Center, Hartford, CT, USA

e-Poster 92

Late diagnosis of developmental dysplasia of the hip in a country using selective ultrasound screening

Frederike Mulder, Hei Sook Femke Hagenmaier, Heleen Staal, Joëlle Rosier, Adhiambo Witlox

Maastricht UMC+, Maastricht, The Netherlands

e-Poster 93

Long-term complications of peripheral nerve blocks in pediatric orthopedic lower extremity procedures: a systematic review

Yifan Mao, Sunny Trivedi, Charlotte Wahle, Dimpy Wraich, Kevin G. Shea, Kesavan Sadacharam, Jennifer J. Beck

David Geffen School of Medicine at UCLA, Los Angeles, CA, USA

e-Poster 94 (Nominated for Best e-Poster)

Optimizing intraoperative irradiation levels for pediatric orthopedics surgeries: radiation doses does matter

Mohamed Laroussi Toumia, Stephanie Pannier, Alina Badina, Bouchra Habib Geryes

Necker University Hospital, APHP, Paris, France

e-Poster 95

POSNA Safe Surgery Program: first-year results for entire POSNA membership

Kali Tileston, Michael G. Vitale, Robert Hyun Cho, Verena M. Schreiber, Henry Bone Ellis, Henry J. Iwinski, Zachary Stinson, Bryan Tompkins, Kevin G. Shea

Stanford University, Palo Alto, CA, USA

e-Poster 96

Safety profile following tibial tubercle osteotomy for adolescents in an ambulatory surgery center

Garrett Sohn, Nolan Daniel Hawkins, Caroline Podvin, Madison Brenner, Savannah Cooper, Benjamin Johnson, Charles Wyatt, Henry Bone Ellis, Philip Wilson

Scottish Rite for Children, Dallas, TX, USA

e-Poster 97

The importance of surgeon dashboarding for comparative quality and safety outcomes when adopting robotics in practice

Alexa Bosco, Nicole Welch, Maty Petcharap*rn, Michelle Marks, Shanika De Silva, Daniel Hedequist

Boston Children’s Hospital, Boston, MA, USA

e-Poster 98 (Nominated for Best e-Poster)

Utilizing neural networks for ultrasound evaluation of developmental dysplasia of the hip

Hsuan Kai Kao, Wei-Chun Lee, Szu-Yao Wang, Wen-E Yang, Chia-Hsieh Chang

Chang Gung Memorial Hospital, Taoyuan, Taiwan

SPINE

e-Poster 99

Two-year follow-up from a prospective study on a posterior dynamic distraction device for adolescent idiopathic scoliosis

Kevin M. Neal, Ron El-Hawary, Gilbert Chan, Geoffrey F. Haft, Timothy S. Oswald, A. Noelle Larson, Ryan Fitzgerald, Alvin C. Jones, Baron S. Lonner, Todd A. Milbrandt, Christina K. Hardesty, John T. Anderson, Michael C. Albert, Nigel J. Price

Nemours Children’s Health, Jacksonville, FL, USA

e-Poster 100

A comparison of intrathecal morphine injection versus intravenous methadone for pain control for posterior spinal fusion in adolescent idiopathic scoliosis

Devan Kumar, Rohini Mahajan Vanodia, Surya Mundluru, Lindsay Michele Crawford, Shiraz A. Younas, Timothy C. Borden

University of Texas Health Science Center at Houston, Houston, TX, USA

e-Poster 101

A comparison of two central sacral vertical line methods and their effect on curve correction

Varun Ravi, Adam A. Jamnik, Alexander Turner, Emeka N. Andrews, Yves Kenfack, David C. Thornberg, Jaysson T. Brooks

Scottish Rite for Children, Dallas, TX, USA

e-Poster 102

Accuracy and safety of 3D-printed patient-specific pedicle screw insertion technique in complex spine deformity correction: analysis of 60 patients performed at a large academic center

Assem Sultan, Omolola Priscilla Fakunle, Mustafa Mahmood, Conner J. Paez, Ahmed K. Emara, Dimitri Joseph Mabarak, Thomas Kuivila, Ryan C. Goodwin

Cleveland Clinic Foundation, Cleveland, OH, USA

e-Poster 103

An efficient, steady, or dual-surgeon allows for the best outcomes?

Vishal Sarwahi, Katherine Eigo, Alex Kwong Juen Ngan, Sarah M. Trent, Sayyida Hasan, Brian Li, Yungtai Lo, Terry D. Amaral

Northwell Health, New Hyde Park, NY, USA

e-Poster 104

Analysis of 5525 consecutive pedicle screws placed utilizing robotically assisted surgical navigation: surgical safety and early complications

Roger F. Widmann, Jenna L. Wisch, Colson Zucker, Olivia Christina Tracey, Tyler Feddema, Florian Miller, Gabriel S. Linden, Mark A. Erickson, Jessica H. Heyer

Hospital for Special Surgery, New York, NY, USA

e-Poster 105

Comparison of perioperative complication rates in congenital scoliosis patients with tethered cord

Andrea Munoz, Leila Mehraban Alvandi, Edina Gjonbalaj, Allyn Morris, Pediatric Spine Study Group, Paul D. Sponseller, Richard Anderson, Jaime A. Gomez

Montefiore Medical Center, Bronx, NY, USA

e-Poster 106

Complexities of orthopedic epidemic: adolescent back pain

Heather M. Richard, Gerrit Franko, Kirsten Tulchin-Francis

Nationwide Children’s Hospital, Columbus, OH, USA

e-Poster 107

Development of pelvic incidence, sacral slope, and pelvic tilt and the effect of age, sex, and BMI: an automated 3D-CT study of 10,969 children and adolescents

Eduardo Novais, Mohammadreza Movahhedi, Munif Hatem, Mallika Singh, Shanika De Silva, Nazgol Tavabi, Grant Douglas Hogue, Young Jo Kim, Sarah D. Bixby, Ata M. Kiapour

Boston Children’s Hospital, Boston, MA, USA

e-Poster 108 (Nominated for Best e-Poster)

Differences in spine growth potential for sanders maturation stages 7A and 7B have implications for treatment of idiopathic scoliosis

Yusuke Hori, Burak Kaymaz, Luiz Carlos Almeida Da Silva, Kenneth Rogers, Petya Yorgova, Peter G. Gabos, Suken A. Shah

Nemours Children’s Hospital, Wilmington, DE, USA

e-Poster 109

Do neuromuscular early-onset scoliosis patients with rib-on-pelvis deformity have decreased reported pain after surgery?

Vineet Desai, Margaret Bowen, Jason Anari, John “Jack” M. Flynn, Jaysson T. Brooks, Brian D. Snyder, Brandon A. Ramo, Jason Howard, Ying Li, Lindsay Andras, Walter Lam Huu Truong, Ryan Fitzgerald, Ron El-Hawary, Benjamin D. Roye, Burt Yaszay, Kenny Kwan, Amy McIntosh, Susan Nelson, Patrick John Cahill, Pediatric Spine Study Group

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 110

Do parents and patients with early-onset scoliosis share the same perspective on health-related quality of life? A comparison of EOSQ-24 and SRS-22 scores

Rachel Gottlieb, John T. Smith, Firoz Miyanji, Juan Carlos Rodriguez, Ron El-Hawary, Ying Li, Pediatric Spine Study Group

University of Michigan, Ann Arbor, MI, USA

e-Poster 111 (Nominated for Best e-Poster)

Early tether rupture prior to 2 years compromises growth modulation by failing to impede convex growth

Ambika Paulson, V. Salil Upasani, Jennifer Hurry, Hui Nian, Christine L. Farnsworth, Peter O. Newton, Stefan Parent, Pediatric Spine Study Group, Ron El-Hawary, Craig R. Louer

Vanderbilt University Medical Center, Nashville, TN, USA

e-Poster 112

Effectiveness of a subcutaneous bupivacaine catheter for pain control and opioid reduction in pediatric spine fusion surgery: a retrospective cohort study

Joshua Acebo, Kenzo Cotton, Emma Wiest, Jordan M. Walters, Eric Siegel, Richard E. McCarthy, David Bumpass

Arkansas Children’s Hospital, Little Rock, AR, USA

e-Poster 113 (Nominated for Best e-Poster)

Have we improved anterior vertebral body tethering outcomes over time? an examination of survivorship trends

Joshua Carroll Tadlock, Peter O. Newton, Tracey P. Bastrom, Stefan Parent, Firoz Miyanji, Harms Study Group

Rady Children’s Hospital, San Diego, CA, USA

e-Poster 114

Hip pain after spinopelvic fixation with sacral alar iliac screws in pediatric neuromuscular scoliosis

Pochih Shen, Mark A. Erickson, Nancy Hadley Miller

Children’s Hospital Colorado, Denver, CO, USA

e-Poster 115

Impact of comorbidities on mortality in neuromuscular patients with early-onset scoliosis

Hiroko Matsumoto, Bhavana Gunda, Taylor-Marie Adams, Sydney Lee, Maria Fernanda Canizares, John T. Smith, Paul D. Sponseller, Mark A. Erickson, Brian D. Snyder, Pediatric Spine Study Group

Boston Children’s Hospital, Boston, MA, USA

e-Poster 116 (Nominated for Best e-Poster)

Intraoperative neuromonitoring events during spinal fusion for scoliosis: a case series

John F. Lovejoy, Mark Lewis, Shane Saifman, Jonathan Daniel Schwartzman, Alec Christian Stall

Nemours Children’s Health, Orlando, FL, USA

e-Poster 117 (Nominated for Best e-Poster)

Is a BrAIST for one, a BrAIST for all? evaluating the effect of the BrAIST trial on spinal fusion rates across race and insurance status

Anthony Catanzano, Tristan Chari, John Atwater, Emily Poehlein, Cindy Green

Duke University, Durham, NC, USA

e-Poster 118

Lowest instrumented vertebra selection in thoracic adolescent idiopathic scoliosis: lowest instrumented vertebra selection drawn for Cotrel–Dubousset original technique including sagittal disc mobility

Benjamin Salle, Benoit De Courtivron, Francois Bergerault, Marc-Florent Tassi, Thierry Odent

CHU Tours Hopital Clocheville, Tours, France

e-Poster 119 (Nominated for Best e-Poster)

Lowest instrumented vertebra in treatment of adolescent idiopathic scoliosis is not correlated with PROMIS scores

Katherine Sborov, Mansi Agarwal, De-An Zhang, Robert Hyun Cho, Cynthia Nguyen, Selina Poon

Shriners Children’s™ Southern California, Pasadena, CA, USA

e-Poster 120

Medical issues complicate 90-day return to the emergency department following spinal deformity surgery

Vishal Sarwahi, Sayyida Hasan, Keshin Visahan, Victor Koltenyuk, Katherine Eigo, Aravind Patil, Terry D. Amaral

Northwell Health, New Hyde Park, NY, USA

e-Poster 121 (Nominated for Best e-Poster)

Magnetic resonance imaging results in patients undergoing surgery for adolescent idiopathic scoliosis: neural axis abnormalities and neurosurgical interventions

Mark Lewis, Kevin M. Neal

Nemours Children’s Health, Jacksonville, FL, USA

e-Poster 122

Multi-disciplinary perioperative pathway for neuromuscular scoliosis patients

Bryce Pember, Lorena Floccari, Richard Steiner, Matt Holloway, Todd F. Ritzman

Akron Children’s Hospital, Akron, OH, USA

e-Poster 123

Novel surface topographic assessment of lung volume in pediatric spinal deformity patients

Jessica H. Heyer, Jenna L. Wisch, Kiranpreet Nagra, Ankush Thakur, Howard Hillstrom, Benjamin Groisser, Colson Zucker, Matthew Cunningham, Michael T. Hresko, Ram Haddas, John S. Blanco, Mary F. Di Maio, Roger F. Widmann, HSS Spinal Alignment Registry

Hospital for Special Surgery, New York, NY, USA

e-Poster 124

Pelvic asymmetry in myelomeningocele associated with scoliosis

Michael Benvenuti, Lawrence I. Karlin

Boston Children’s Hospital, Boston, MA, USA

e-Poster 125

Peri-operative outcomes of posterior dynamic deformity device compared to vertebral body tethering for adolescent idiopathic scoliosis

Julia Todderud, A. Noelle Larson, Geoffrey F. Haft, Ron El-Hawary, John T. Anderson, Ryan Fitzgerald, Timothy S. Oswald, Gilbert Chan, Baron S. Lonner, Michael C. Albert, Daniel G. ho*rnschemeyer, Todd A. Milbrandt

Mayo Clinic, Rochester, MN, USA

e-Poster 126

Plastic multilayered closure reduces surgical site infections in pediatric neuromuscular scoliosis surgery

Jason Amaral, McKenna C. Noe, Rebecca Schultz, Tristen Taylor, John T. Anderson, Richard M. Schwend, Brian G. Smith

Baylor College of Medicine, Houston, TX, USA

e-Poster 127

PROMIS and ODI tools: clinically useful predictors of abnormal magnetic resonance imagings in pediatric back pain?

Devan James Devkumar, Karina A. Zapata, Chan-Hee Jo, Brandon A. Ramo

Scottish Rite for Children, Dallas, TX, USA

e-Poster 128

Put a ring on it! wedding band connectors have fewer complications than tandem connectors in traditional growing rod constructs

Sydney Lee, Kelsey Mikayla Flowers Zachos, Paul D. Sponseller, Peter F. Sturm, Matthew E. Oetgen, John B. Emans, Grant Douglas Hogue, Pediatric Spine Study Group

Boston Children’s Hospital, Boston, MA, USA

e-Poster 129 Withdrawn

e-Poster 130

Rigo Cheneau brace for adolescent idiopathic scoliosis: higher in brace correction and lower rates of curve progression

Lisa Bonsignore-Opp, Ritt Givens, Rajiv Iyer, Hiroko Matsumoto, Nicole Bainton, Benjamin D. Roye, Michael G. Vitale

Columbia University, New York, NY, USA

e-Poster 131

Rigo versus Boston Brace for the treatment of adolescent idiopathic scoliosis

Qais Zai, Petar Golijanin, Romil Shah, Cortney Matthews, Kirsten Ross, Brian Edward Kaufman

Dell Medical School at the University of Texas at Austin, Austin, TX, USA

e-Poster 132

Risk of proximal junctional kyphosis after revision of growing rod constructs

Chidebelum Nnake, Alondra Concepción-González, Matan Malka, Simon Blanchard, Ron El-Hawary, Michael G. Vitale, Pediatric Spine Study Group, Benjamin D. Roye

Columbia University Irving Medical Center, New York, NY, USA

e-Poster 133

Safety and efficacy of a novel technique for posterior column osteotomy in patients with adolescent idiopathic scoliosis undergoing posterior spinal fusion

Alec Christian Stall, Ryan M. Ilgenfritz, Naveed Nabizadeh, Michael Read

Nemours Children’s Health, Orlando, FL, USA

e-Poster 134

Screening magnetic resonance imaging in congenital early-onset scoliosis: is it safe to delay advanced imaging to decrease early anesthesia?

Evan Mostafa, Leila Mehraban Alvandi, Edina Gjonbalaj, John B. Emans, Paul D. Sponseller, Purnendu Gupta, A. Noelle Larson, Pediatric Spine Study Group, Jaime A. Gomez

Montefiore Medical Center, Bronx, NY, USA

e-Poster 135

Similar results with less spinal cord exposure: comparison of in situ osteotomies with traditional Ponte osteotomies in adolescent idiopathic scoliosis

Ian Hollyer, Katherine Margaret Krenek, Kali Tileston, Meghan N. Imrie, Lawrence A. Rinsky, Kelly Heavner McFarlane, John Vorhies, RetroPonte

Stanford University, Palo Alto, CA, USA

e-Poster 136

The fate of the broken tether: how do curves treated with vertebral body tethering behave after tether breakage?

Tyler A. Tetreault, Tiffany Phan, Tishya A.L. Wren, Michael J. Heffernan, Michelle C. Welborn, John T. Smith, Ron El-Hawary, Kenneth M.C. Cheung, Kenneth David Illingworth, David L. Skaggs, Lindsay Andras, Pediatric Spine Study Group

Children’s Hospital Los Angeles, Los Angeles, CA, USA

e-Poster 137

The impact of operating room process versus team standardization on outcomes in pediatric spinal deformity surgery

Vishal Sarwahi, Katherine Eigo, Sarah M. Trent, Alex Kwong Juen Ngan, Aravind Patil, Brian Li, Yungtai Lo, Terry D. Amaral

Northwell Health, New Hyde Park, NY, USA

e-Poster 138

Thoracic deformity index correlates with poorer pre-operative pulmonary function testing in patients with adolescent idiopathic scoliosis of the thoracic spine

Charles Mechas, Trey William Moberly, Alison Dittmer, Vishwas R. Talwalkar, Ryan D. Muchow, Vincent Prusick

University of Kentucky/Shriners Children’s™ Lexington, Lexington, KY, USA

e-Poster 139

Vertebral body tethering versus posterior spinal fusion for Lenke 1 adolescent idiopathic scoliosis: a single surgeon comparison with 2- to 6-year follow-up

Baron S. Lonner, Ashley Wilczek, Rodnell Busigo Torres, Rami Rajjoub, Mateo Restrepo Mejia, Lily Eaker

Mount Sinai Hospital, New York, NY, USA

e-Poster 140

What factors impact flexibility after spinal fusion?

Vishal Sarwahi, Sayyida Hasan, Keshin Visahan, Brittney Moncrieffe, Katherine Eigo, Aravind Patil, Sarah M. Trent, Alex Kwong Juen Ngan, Terry D. Amaral

Northwell Health, New Hyde Park, NY, USA

SPORTS

e-Poster 141

A cadaveric study of the sagittal patellar insertion of the medial patellofemoral ligament in children: implications for reconstruction

Amin Alayleh, Ian Hollyer, Thomas M. Johnstone, Bryan Khoo, Chiamaka Nneka Obilo, Kelly Heavner McFarlane, David Baird, Calvin Chan, Kevin G. Shea

Stanford University, Palo Alto, CA, USA

e-Poster 142

Biomechanical comparison of four “hashtag” suture patterns for repair of lateral meniscus radial tears

Kelly Heavner McFarlane, David Baird, Thomas Michael Johnstone, Amin Alayleh, Chiamaka Nneka Obilo, Bryan Khoo, Christian Wright, Vanessa Taylor, Ian Hollyer, Calvin Chan, Marc Tompkins, Henry Bone Ellis, Theodore J. Ganley, Yi-Meng Yen, Seth Sherman, Kevin G. Shea

Stanford University, Palo Alto, CA, USA

e-Poster 143 (Nominated for Best e-Poster)

Different roads traveled: disparities in the preoperative timeline result in delays to pediatric anterior cruciate ligament reconstruction

Michelle Andreea Nutescu, Samuel I. Rosenberg, Elizabeth Merritt, Neeraj Patel

Ann & Robert H. Lurie Children’s Hospital of Chicago, Chicago, IL, USA

e-Poster 144

Discoid meniscus with anterior instability: incidence, presentation, diagnosis, treatment, and outcomes

Joseph N. Charla, Emily Ferreri, Leila Mehraban Alvandi, Edina Gjonbalaj, Jacob Schulz, Eric Fornari, Mauricio Drummond

Children’s Hospital at Montefiore, Bronx, NY, USA

e-Poster 145

Factors associated with return to sports in patients undergoing anterior cruciate ligament surgery: a 20-year analysis at a tertiary-care children’s hospital

Benton E. Heyworth, James Pruneski, Melissa A. Christino, Mininder S. Kocher, Dennis Kramer, Lyle J. Micheli, Matthew D. Milewski, Yi-Meng Yen, Nazgol Tavabi, Ata M. Kiapour

Boston Children’s Hospital, Boston, MA, USA

e-Poster 146

Hamstring autograft is associated with increased knee valgus moment after anterior cruciate ligament reconstruction: a biomechanical analysis of autograft selection after anterior cruciate ligament reconstruction

Sailesh V. Tummala, Neeraj Vij, Kaycee Glattke, Amber Brennan, Jenni Winters, Seyed Hadi Salehi, Anikar Chhabra, Heather Menzer, ACL Study Group

Phoenix Children’s Hospital, Phoenix, AZ, USA

e-Poster 147

High frequency of meniscal injuries found in adolescents with anterior cruciate ligament tears

John Logan Reynolds, Tim Westbrooks, Kyle Boden, Austin V. Stone, Mary Lloyd Ireland, Darren Johnson, Benjamin Wilson

University of Kentucky, Lexington, KY, USA

e-Poster 148

Osteochondritis dissecans of the talus: composite cancellous bone and morselized allograft cartilage grafting results in excellent patient-reported outcomes and return to play

Patrick Ojeaga, Nolan Daniel Hawkins, Terrul Ratcliff, Rishi Sinha, Benjamin Johnson, Charles Wyatt, Henry Bone Ellis, Philip Wilson

Scottish Rite for Children, Dallas, TX, USA

e-Poster 149

Predictive characteristics of meniscal tear locations with concomitant anterior cruciate ligament injury in adolescents

Savannah Rose Troyer, David R. Howell, Claire Giachino, Hannah Rossing, Amanda Kass, Neeraj Patel, Jay C. Albright, Curtis Daniel VandenBerg

University of Colorado, Denver, CO, USA

e-Poster 150

Rates of reoperation and readmission following arthroscopic pediatric and adolescent knee surgery: data from the SCORE patient registry, 2018–2022

Philip Wilson, Gregory Knell, Robert Yockey, James Joseph McGinley, Philip Austin Serbin, Garrett Sohn, Henry Bone Ellis, SCORE

Scottish Rite for Children, Frisco, TX, USA

e-Poster 151

Surgical management and long-term follow-up of congenital and obligatory patellar dislocation in children

Roy Gigi, Addy S. Brandstetter, Barry Danino, Inbar Lidor, Amit Benady, Dror Ovadia, Moshe Yaniv

Tel Aviv Sourasky Medical Center – Ichilov Hospital, Tel Aviv, Israel

e-Poster 152

Your patella dislocated: will it happen again? an assessment of magnetic resonance imaging criteria for recurrent patella dislocation after an initial event

Jason Brenner, Leila Mehraban Alvandi, Steven Maxwell Henick, Edina Gjonbalaj, Benjamin J. Levy, Jacob Schulz, Eric Fornari, Mauricio Drummond

Children’s Hospital at Montefiore, Bronx, NY, USA

TRAUMA

e-Poster 153

“Heat mapping” of pediatric and adolescent gun violence in an urban center: is targeted intervention one possible solution?

Emerson Rowe, Abbey Glover, Martin J. Herman

Drexel University College of Medicine, Philadelphia, PA, USA

e-Poster 154

A clinical and scientific paradigm shift: revisiting growth after pediatric radius fracture plating

Rachel Lenhart, Pille-Riin Värk, Keith D. Baldwin, Christine Goodbody, Jonathan G. Schoenecker, Apurva S. Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 155

A prospective cohort analysis of two non-operative treatment modalities for the management of pediatric type II supracondylar humerus fractures

Mary Sun, Emily Schaeffer, Vuong Nguyen, Kishore Mulpuri, Christopher W. Reilly

BC Children’s Hospital, Vancouver, BC, Canada

e-Poster 156

A single retrograde intramedullary nail technique for treatment of displaced proximal humeral fractures in adolescents: case series and review of the literature

Eri Samara, Nicolas Lutz

Children’s University Hospital of Lausanne, Lausanne, Switzerland

e-Poster 157

Acetabular “fleck” sign: outcomes of surgical repair

Daniel Gaines, Stephanie Chen, Kirsten Tulchin-Francis, Elizabeth Badowski, Craig Smith, Kevin E. Klingele

Nationwide Children’s Hospital, Columbus, OH, USA

e-Poster 158

Avoiding trouble with pediatric capitellar fractures: unusual fracture variants, trash lesions, and treatment pearls

Soroush Baghdadi, Daniel Yang, Pille-Riin Värk, Keith D. Baldwin, Eliza Buttrick, Apurva S. Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 159

Changes in femoral anteversion after intramedullary nail for pediatric femoral shaft fracture: a multicenter study

Jae Jung Min, Soon-Sun Kwon, Kibeom Youn, Daehyun Kim, Ki Hyuk Sung, Moon Seok Park

Seoul National University Bundang Hospital, Seongnam, Republic of South Korea

e-Poster 160

Closed reduction techniques lead to fewer complications than open reductions in treating minimally and moderately displaced pediatric lateral humeral condyle fractures: a multicenter study

Abhishek Tippabhatla, Beltran Torres-Izquierdo, Daniel Pereira, Rachel Goldstein, Julia Skye Sanders, Kevin M. Neal, Laura Bellaire, Jaime Rice Denning, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

e-Poster 161

Comminuted ulna fractures and nerve injuries: an investigation in Monteggia dislocations

Jason Amaral, Basel Touban, Rebecca Schultz, Jacob Scioscia, Pablo Coello, Aharon Zvi Gladstein, Scott D. McKay

Baylor College of Medicine, Houston, TX, USA

e-Poster 162

Diagnosis and treatment of lateral to medial diagonal injury of the elbow in children: concomitant medial epicondylar and radial neck fractures

Yunan Lu, Federico Canavese, Shunyou Chen

Fuzhou Second Hospital, Fuzhou, People’s Republic of China

e-Poster 163

Do post-operative immobilization protocols and physical therapy impact return of elbow motion following pinning of supracondylar humerus type-III fractures?

Akbar Nawaz Syed, Pooja Nilesh Balar, Margaret Bowen, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 164

Effect of serum vitamin D levels in pediatric fracture occurrence

David Liu, Susan T. Mahan, Taylor-Marie Adams, Hiroko Matsumoto, Melissa S. Putman, Brian D. Snyder

Boston Children’s Hospital, Boston, MA, USA

e-Poster 165

Effects of casting material on reduction maintenance

Emily Boschert, Catalina Baez, Alexis Clifford, Aaron Jennings, Stephanie Ihnow, Jessica McQuerry

University of Florida, Gainesville, FL, USA

e-Poster 166

Elastic stable intramedullary nail treatment of pediatric femoral shaft fractures: fracture stability does not predict malunion or major complications

Nandini Patel, Charles T. Mehlman, Jaime Rice Denning, Wendy Ramalingam

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

e-Poster 167

Elastic stable intramedullary nail treatment of pediatric tibial shaft fractures: patients 75 pounds and over have higher risk malunion

Justin A. Jebackumar, Charles T. Mehlman, Jaime Rice Denning, Wendy Ramalingam

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

e-Poster 168

Enhanced radiographic union score (RUST) of adolescent tibia shaft fractures treated with hexapod circular external fixation: a multicenter study of 38 consecutive cases

Ahmed Hagag, Ibrahim Feras Salama, Anirejuoritse Bafor, Kyle Jay Klahs, Dillon Stone, Amr Atef Abdelgawad, Christopher A. Iobst

El Paso Children Hospital and Texas Tech Health Science Center, El Paso, TX, USA

e-Poster 169

Financial implications associated with use of waterproof casting material in pediatric patients

Alexis Clifford, Aaron Jennings, Catalina Baez, Emily Boschert, Stephanie Ihnow, Jessica McQuerry

University of Florida, Gainesville, FL, USA

e-Poster 170 (Nominated for Best e-Poster)

Healthcare utilization following closed reduction and percutaneous pinning of supracondylar humerus fractures

Elizabeth Cinquegrani, Matthew Van Boxtel, Jessica Hanley

Medical College of Wisconsin, Milwaukee, WI, USA

e-Poster 171

Implant selection and complications in pediatric Monteggia fracture dislocations

Jason Amaral, Rebecca Schultz, Basel Touban, Pablo Coello, Nihar Pathare, Aharon Zvi Gladstein, Scott D. McKay

Baylor College of Medicine, Houston, TX, USA

e-Poster 172

Incidence and long-term follow-up of lateral condyle fractures

Mikaela Sullivan, Elizabeth Wellings, Prabin Thapa, A. Noelle Larson, William J. Shaughnessy, Anthony A. Stans, Todd A. Milbrandt

Mayo Clinic, Rochester, MN, USA

e-Poster 173

Interfacility transfer of pediatric supracondylar elbow fractures: transfer by ambulance shows no advantage in speed of transfer or prevention of complications

Spencer Richardson, Sarah T. Levey, Joash Rajesh Suryavanshi, Amrit Parihar, Curtis Vrabec, Robert Tysklind, Robert J. Bielski

Indiana University, Indianapolis, IN, USA

e-Poster 174

Intimate partner violence in teenagers: why should the pediatric orthopedic surgeon care?

Bharti Khurana, Rose Olson, Jeff Temple, Randall T. Loder

Riley Children’s Hospital, Indianapolis, IN, USA

e-Poster 175

Is tibial intramedullary nail placement safe when placed across open physes?

Grant McHorse, K. John Wagner, Matthew D. Ellington, Christopher D. Souder

Dell Medical School at the University of Texas at Austin, Austin, TX, USA

e-Poster 176

Lateral overgrowth in surgically treated pediatric lateral condyle fractures

Adele Bloodworth, Shrey Nihalani, Gerald McGwin, Kevin Williams, Michael J. Conklin

University of Alabama at Birmingham, Birmingham, AL, USA

e-Poster 177

Magnetic resonance imaging without sedation or anesthesia can guide treatment of minimally displaced pediatric lateral humeral condyle fractures

Rana Nabil Nouri, Jonas Sterup Bovin, Hilla Matilda Biermann, Kasper Gosvig, Morten Jon Andersen

Copenhagen University Hospital - Herlev and Gentofte, Copenhagen, Denmark

e-Poster 178

Nonunions of surgically treated pediatric humeral lateral condylar fractures: risk factors and outcomes

Abhishek Tippabhatla, Beltran Torres-Izquierdo, Laura Bellaire, Rachel Goldstein, Julia Skye Sanders, Kevin M. Neal, Jaime Rice Denning, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

e-Poster 179

Novel radiographic predictors of diaphyseal forearm fracture malrotation: a cadaveric analysis

Samuel Renfro, Alexander Dan-Fong Li, Kelly Hogan, Andrew Henebry, Mark Katsma, Vanna Rocchi

Naval Medical Center Portsmouth, Portsmouth, VA, USA

e-Poster 180 (Nominated for Best e-Poster)

Operative versus nonoperative treatment of displaced proximal humerus fractures in adolescents: results of a prospective multicenter study

Beltran Torres-Izquierdo, Abhishek Tippabhatla, Keith D. Baldwin, V. Salil Upasani, Julia Skye Sanders, Rachel Goldstein, Jaime Rice Denning, Claire Schaibley, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

e-Poster 181

Opioid prescription patterns 30 days after pediatric supracondylar humerus fracture closed reduction and percutaneous pinning

Jack Haglin, David Deckey, Tony Gaidici, Daniel Gaines, Judson W. Karlen, Jessica Davis Burns

Phoenix Children’s Hospital, Phoenix, AZ, USA

e-Poster 182

Orthopedic fixation of skeletally immature ankle fractures in children and adolescents using bio-integrative implants

Evan McNall, Mark E. Solomon, Joslin Lashay Seidel, Hannah Schneiders, David Lin, ORIF Ankles

The Pediatric Orthopedic Center, Cedar Knolls, NJ, USA

e-Poster 183

Pediatric patients who sustain gunshot wound–related fractures are at higher risk of developing addiction and psychiatric disorders

David Momtaz, Rishi Gonuguntla, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

e-Poster 184 (Nominated for Best e-Poster)

Pediatric talar neck fractures outcomes and complications: a 20-year review

Shrey Nihalani, Adele Bloodworth, Michael J. Conklin, Philip Ashley

University of Alabama at Birmingham, Birmingham, AL, USA

e-Poster 185

Please do not x-ray my healed fracture! utility of repeat radiographs during treatment of pediatric diaphyseal clavicle fractures

Robert William Gomez, David Jessen, Morgan Storino, Zachary John Lamb, Dustin A. Greenhill

St. Luke’s University Health Network, Bethlehem, PA, USA

e-Poster 186

Polymer-based biodegradable implants can be used safely instead of k-wires and screws in pediatric trauma: an experience of 495 children and 12 years

Marcell Benjamin Varga, Gergo Józsa, Tamás Kassai, Zsófia Krupa

Manninger Jenő Baleseti Központ, Budapest, Hungary

e-Poster 187

Radiographic predictors of displacement in transitional ankle fractures: can we avoid a computed tomography scan on all patients?

Luke Sang, Alex H. Youn, Katherine E. Bach, Steven M. Garcia, Ishaan Swarup

UCSF Benioff Children’s Hospital, Oakland, CA, USA

e-Poster 188

Rolling up the sleeve: patient characteristics and postoperative outcomes of surgically treated inferior pole patellar sleeve fractures

Vineet Desai, Christopher John DeFrancesco, Joseph Yellin, Brendan Williams

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

e-Poster 189 Withdrawn

e-Poster 190

The alarming trends in the epidemiology and risk factors of non-accidental fractures in children

Soroush Baghdadi, David Momtaz, Beltran Torres-Izquierdo, Daniel Pereira, Mehul Mittal, Rishi Gonuguntla, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

e-Poster 191

The effects of atypical fracture morphology on the need for open reduction in pediatric supracondylar humerus fractures

Bartu Sarisozen, Cenk Ermutlu, Yücel Bilgin, Saltuk Bugra Güler, Ishak Sayan

Bursa Uludag University, Bursa, Turkey

e-Poster 192 (Nominated for Best e-Poster)

There is no role for isolated closed reduction in displaced proximal humerus fractures in adolescents: results of a prospective multicenter study

Beltran Torres-Izquierdo, Abhishek Tippabhatla, Keith D. Baldwin, V. Salil Upasani, Julia Skye Sanders, Rachel Goldstein, Jaime Rice Denning, Claire Schaibley, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

e-Poster 193

Trampoline-related fractures in 1063 consecutive children and adolescents

Roope Parviainen, Topi Aaretti Laaksonen, Jaakko Sinikumpu, Matti Mikael Ahonen

New Children’s Hospital, HUS, Helsinki, Finland

e-Poster 194

Underdiagnosis of pediatric lateral ankle avulsion injuries: an ultrasound study

Jacob Jones, Cassidy Schultz, Bobby Van Pelt, Caroline Podvin, Jane Soyeun Chung, Shane Miller, Charles Wyatt, Benjamin Johnson, Henry Bone Ellis, Philip Wilson

Scottish Rite for Children, Dallas, TX, USA

e-Poster 195

Understanding the impact of family member presence during pediatric forearm fracture reductions in the emergency department

Elizabeth Wacker, Paige Gloster, Wendy Ramalingam

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

e-Poster 196 (Nominated for Best e-Poster)

Utility of follow-up X-ray in type I supracondylar humerus fracture

Shrey Nihalani, Adele Bloodworth, Katie Frith, Philip Ashley, Kevin Williams, Michael J. Conklin

University of Alabama at Birmingham, Birmingham, AL, USA

e-Poster 197

Who should see my child? differences between pediatric and non-pediatric orthopedic specialists during treatment of pediatric diaphyseal clavicle fractures

Robert William Gomez, Morgan Storino, David Jessen, Zachary John Lamb, Dustin A. Greenhill

St. Luke’s University Health Network, Bethlehem, PA, USA

OP-1

Radiological, clinical, and functional outcome of children with traumatic hip dislocation: review of 66 cases

Sara De Salvo, Shunyou Chen, Fabio Sammartino, Jeanne-Agathe Mujadiki Luesa, Yunan Lu, Wentao Wang, Liwei Shi, Lianyong Li, Vito Pavone, Federico Canavese, France-China-Italy Traumatic Hip Dislocation Study Group

CHU Lille, Lille, France

LOE-Prognostic-Level III

Purpose: Current understanding of the outcomes of traumatic hip dislocation (THD) in pediatric patients is still limited. This study aims to assess the radiological, clinical, and functional results of patients with THD, whether in isolation or in conjunction with acetabular (ACF) or proximal femur (PFF) fracture, and to identify potential risk factors for unfavorable outcomes.

Methods: This is a retrospective study of pediatric patients with THD consecutively enrolled at three different institutions between January 2016 and July 2023. Patients were categorized into three groups: isolated THD (Group A), THD with ACF (Group B), and THD with PFF (Group C). Standard radiographs were utilized to classify each THD and identify the presence of any other associated bone lesions. Clinical and functional outcomes were assessed via the Harris Hip score (HHS). Avascular necrosis (AVN) was determined according to the Ratliff criteria. The association between outcome and associated injuries, age at trauma (≤10 versus > 11 years), traumatic mechanism (low energy versus high energy), reduction type (open versus closed), and dislocation’s direction (posterior versus anterior) was evaluated.

Results: Sixty-six cases of unilateral THD (63 posterior) were analyzed, consisting of 42 males and 24 females, with an average age of 10.5 years (3–18 years). Out of these, 25 patients were aged ≤10 years (37.88%), of which 18 had low-energy trauma. Meanwhile, 41 patients were >11 years old (62.12%), of which 25 had high-energy trauma (p < 0.0001). It was observed that Group A patients were significantly younger than those in groups B and C (p < 0.0001). Group A had 5/31 patients with labral injury (16.1%), Group B had 2/22 patients with AC fractures misdiagnosed >3 weeks after injury (18%), and Group C had 3/13 patients with AVN (23%). Most patients exhibited a favorable mean HHS (92.17; SD: ±7.16), except for individuals with AVN and those with misdiagnosed AC fractures (p < 0.05).

Conclusions: The outcome of THD is worse in patients with AVN secondary to PF fracture, misdiagnosed AC fractures, high-energy trauma, and older age at the time of injury. A computed tomography (CT) scan is necessary to rule out AC fractures in isolated dislocations. If pain persists after reduction, a magnetic resonance imaging (MRI) is needed to uncover labral injury. Timely diagnosis and treatment of these lesions typically lead to a favorable outcome.

Significance: In more than 50% of THD cases, there are associated injuries that must be eliminated being significant risk factors for negative outcomes.

OP-2

Diaphyseal femur fractures in children under the age of 3—risk factors for non-accidental trauma: a CORTICES multi-center study

Manya Bali, Patricia E. Miller, Benjamin J. Shore, Scott B. Rosenfeld, CORTICES

Boston Children’s Hospital, Boston, MA, USA

LOE-Prognostic-Level III

Purpose: The American Academy of Orthopaedic Surgeons (AAOS) recommends that children (<36 months) who present with a diaphyseal femur fracture (DFF) undergo Non-Accidental Trauma (NAT) workup. Compliance with this recommendation has been reported to be poor and identification of risk factors associated with positive NAT diagnosis, elusive. The purpose of this study was to analyze a multicenter national database to calculate the frequency of NAT screening, NAT diagnosis, and risk factors associated with a positive NAT diagnosis in children (<36 months) presenting with a DFF.

Methods: A total of 1263 children (<36 months) with DFF presenting to one of 15 CORTICES hospitals were identified. Positive NAT was recorded when a child was removed from their caregivers by CPS. Percent compliance of NAT screening and proportion of patients who received a positive NAT diagnosis were calculated with 95% confidence interval (CI). Multivariable logistic regression analysis was used to determine factors associated with positive NAT.

Results: The median age was 23 months (0.2–36 months). Seventy-one percent were male. Fifty-six percent (704/1263) underwent NAT evaluation (95% CI, 52.9–58.5). Fifteen percent of all patients had a positive NAT diagnosis (185/1263; 95% CI = 12.8–16.7). Of the 704 patients who underwent NAT evaluation, 26% had a positive NAT diagnosis (95% CI = 23.1–29.7). Multivariable logistic regression analysis found children <15.4 months to be 5.5 times (odds ratio (OR) = 5.52; 95% CI = 4.14–7.37; p < 0.001) more likely of being diagnosed with NAT compared to older children. Patients who identified as non-White had two times the odds of a positive NAT diagnosis compared to patients identifying as White (OR = 2.04; 95% CI = 1.53–2.71; p = 0.01). For each 10-unit increase in Area Deprivation Index (ADI), the odds of a positive NAT diagnosis increased by 18% (OR = 1.18; 95% CI = 1.17–1.19; p = 0.007). Patients with conflicting mechanism of injury had 3.5 times the odds (OR = 3.49; 95% CI = 2.45–4.98; p < 0.001) of a positive NAT diagnosis.

Conclusions: Only 56% of patients were evaluated for NAT; however, 26% of those evaluated were positive for NAT. Younger age, race, socioeconomic factors (defined here by ADI), and unknown mechanism of injury are risk factors to consider when assessing for NAT in children (<36 months) with DFF.

Significance: This is the largest report on the risk of NAT associated with children <36 months presenting with DFF. It is the first use multicenter/multi-region data to confirm previously reported risk factors. It is also the first report to link socioeconomic factors (ADI) to NAT in this population. Improved national compliance with NAT screening is necessary to improve the care we provide to our children.

OP-3

Increased odds of non-accidental traumatic fractures in pediatric patients with intellectual disability disorder: a stratified analysis

Rishi Gonuguntla, David Momtaz, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh

Washington University in St. Louis, St. Louis, MO, USA

LOE-Prognostic-Level III

Purpose: Pediatric patients with an intellectual disability disorder (IDD) are known to be at a higher risk of experiencing child abuse. In this study, we aim to determine the odds of a pediatric patient experiencing a non-accidental traumatic fracture (NATF) and stratify this by degree of intellectual disability when compared to accidental traumatic fractures (ATFs).

Methods: A large, nationally representative sample of 15,802,711 children was identified, with 16,441 of those patients sustaining NATF and 15,786,270 sustaining an ATF between 1 January 2003 and 31 December 2022. Of these patients, 260 of the NATF patients had some degree of IDD, and 3450 of the ATF patients had some degree of IDD. Patients were then stratified by degree of IDD. Retrospective cohort analysis was performed to determine odds ratios of patients in each category to sustain an NATF compared to an ATF.

Results: When comparing patients with profound intellectual disability to those without intellectual disability, patients had a 184.28 times greater odds of sustaining an NATF (p < 0.0001), patients with severe intellectual disability had a 145.523 times greater odds of sustaining an NATF (p < 0.0001), patients with moderate intellectual disability had a 36.34 times greater odds of sustaining an NATF (p < 0.0001), and patients with a mild intellectual disability had a 35.32 times greater odds of sustaining an NATF (p < 0.0001) (Figure 1).

Conclusions: Patients with increasingly severe intellectual disability had increasing odds to sustain an NATF relative to patients without intellectual disability. It is critical that physicians are aware of this relationship to identify patients who may be at increased risk of experiencing abuse.

Significance: The stark escalation in odds of NATF with increasing severity of intellectual disability underscores a dire need for enhanced physician awareness, improved preventive measures, and stringent child protection protocols.

EPOS/POSNA Abstract Book (2)

OP-4

Ischial tuberosity avulsion fractures: treatment and return to sport in athletes with displaced fragments

Jayson Saleet, Eduardo Novais, Yi-Meng Yen, Mininder S. Kocher, Lyle J. Micheli, Benton E. Heyworth

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level III

Purpose: Ischial tuberosity avulsion fractures are relatively rare injuries that typically occur in young athletes during activity. Some patients may experience significant morbidity, often through chronic pain and changes in sports participation. The influence of fragment displacement on optimal treatment and proper return to sport protocol has not been well investigated. This study sought to evaluate the relationship between displacement and both choice of treatment and time to return to sport.

Methods: Retrospective analysis of ischial tuberosity avulsion fractures in pediatric patients between 2010 and 2021 at Boston Children’s Hospital was completed. Information regarding demographics, treatment, and recovery were extracted from patient charts. Plain radiographs and magnetic resonance imaging (MRI) were analyzed to measure fragment displacement at the ischial apophysis. Treatment protocol, return to sport (RTS) time, and complications were analyzed.

Results: Eighty-eight patients with an ischial tuberosity avulsion fracture were identified. Sixty-four (73%) were treated non-operatively, 8 (9%) were treated acute operatively (within 6 weeks), and 16 (18%) were treated chronic operatively (>6 weeks). Imaging for measurement of fragment displacement was available for 86 (98%) patients. The median displacement was 0.2 cm for the non-operative group, 2.2 cm for the acute operative group, and 1.5 cm for the chronic operative group. Of the 86 patients with available imaging, 67 (78%) had an RTS time. The median RTS was 3.6 months in the non-operative group, 5.5 months in the acute operative group, and 13.3 months in the chronic operative group.

Conclusions: In this retrospective cohort study, nearly all fractures with displacement ≥1.0 cm were surgically treated, either acutely or at a delayed time point because of failure of non-operative treatment. All patients who underwent acute operation had displacement >1.0 cm, while 87% of those undergoing delayed operation had displacements >1.0 cm. The vast majority of those treated non-operatively had displacement <1 cm, with only three patients in the series having successful return to sport despite displacement >1 cm. Overall, non-operatively treated patients returned to sport approximately 1 month earlier than those undergoing acute operation and several months prior to those with delayed surgical intervention. These data suggest that patients with displacement <1.0 cm may be successfully treated non-operatively while greater displacement most commonly underwent surgical to ultimately optimize outcome and return to sport.

Significance: This study suggests that there may be an approximate threshold measure of displacement at which ischial tuberosity avulsion fractures may be considered for operative treatment to result in the most successful outcomes.

EPOS/POSNA Abstract Book (3)

OP-5

Pre-existing femoro-acetabular impingement is associated with pelvic avulsion fractures in adolescents: a matched cohort study

Miles Batty, Samantha L. Ferraro, Munif Hatem, Patricia E. Miller, Benton E. Heyworth, Sarah D. Bixby, Eduardo Novais

Boston Children’s Hospital, Boston, MA, USA

LOE-Not Applicable-Level III

Purpose: Apophyseal pelvic avulsion fractures occur almost exclusively in the adolescent athlete population. A possible relationship between femoro-acetabular impingement (FAI) and pelvic avulsion fractures has been discussed in the literature, but no prior studies have investigated the hip morphology of patients with pelvic avulsion fractures. The purpose of this study is to use computed tomography (CT) imaging to compare morphologic femoral and acetabular measurements of adolescents who sustained a pelvic avulsion fracture to those of gender- and age-matched controls. We hypothesize that a higher incidence of radiographic FAI will be found in patients with pelvic avulsion fractures than in the matched control patients.

Methods: Cases of pelvic avulsion fractures were retrospectively reviewed from the electronic medical records at a tertiary care pediatric center. Patients with CT imaging of the hip near the time of injury were included for analysis. The avulsion fracture cohort was matched in a 1:2 ratio to non-fractured hips with CT imaging based on age and sex. Cranial acetabular version, central acetabular version, lateral center edge angle, and alpha angles—anterior, anterior-superior, superior, posterior-superior, posterior—were measured for all subjects. Radiographic measurements were compared between the avulsion cohort and matched controls using independent sample Wilcoxon rank-sum tests. A logistic regression model estimated the effect of the presence of avulsion fracture on the likelihood of CAM impingement (any alpha angle >55°).

Results: Thirty-four hips with avulsion fractures were matched to 68 hips without avulsion fractures for analysis. Avulsion fracture subjects had 2.5 times the odds of impingement, compared to controls (odds ratio (OR) = 2.5; p = 0.04). The anterior-superior alpha angle was 5° higher for the avulsion cohort compared to controls (median, 58° versus 53°; p = 0.03). Additional findings include a 2° lower superior alpha angle (median, 40° versus 42°; p = 0.03) and 3° higher central acetabular version (median, 17° versus 14°; p = 0.03) for the avulsion group compared to controls.

Conclusions: Our findings demonstrate that patients with an apophyseal pelvic avulsion fracture are significantly more likely to show radiographic evidence of FAI when compared to matched controls. These data may represent a morphologic predisposition to avulsion fractures among adolescents with pre-existing FAI.

Significance: This is the first study to identify pre-existing morphologic features of the hip that are associated with adolescent pelvic avulsion fractures. In addition, this adds to the list of injuries that have been shown in the literature to be associated with FAI.

OP-6

An emerging healthcare crisis: trends in pediatric firearm injuries over time—analysis of over 1100 cases

Claire Sentilles, Elizabeth Lane Whitman, Keith Jayson Orland, Abu Mohd. Naser, Jonathan Rowland, Jeffrey R. Sawyer, Benjamin West Sheffer, David D. Spence, William C. Warner, Derek M. Kelly

Campbell Clinic, Germantown, TN, USA

LOE-Not Applicable-Level III

Purpose: Behind motor vehicle accidents, gunshot injuries are the leading cause of injury-related death in the pediatric population in the United States. The goal of this study was to analyze trends among children with firearm injuries to better understand if certain age groups, mechanisms of injury, and type of firearms were driving the increasing rates of pediatric gun-related trauma.

Methods: This study includes pediatric gunshot wound patients who presented to a single free-standing level 1 pediatric hospital or died at the scene from 2010 to 2021. All the hospital data were collected prospectively as part of a level 1 trauma system database. All the death data were collected from the local coroner’s office. Patients were grouped according to age (0–1 years, 1–4 years, 5–9 years, 10–14 years, 15+ years), mechanism of injury (suicide, assault, accident, unknown), and weapon type (handgun, air gun, BB gun, shotgun, hunting rifle, unknown, other).

Results: From 2010 to 2021, there were 1126 pediatric gunshot injuries in the geographic region studied. The incidence of firearm trauma in pediatric patients has increased rapidly over the time studied. Rise in injury rates occurred most strikingly in the older adolescent age groups 3 and 4 (Figure 1a), in the category of assault (Figure 1b), and among handguns (Figure 1c). Younger age groups, suicides, accidents, and injury by hunting rifle remained relatively stable over time.

Conclusions: Firearm injuries are the second leading cause of injury-related death in the pediatric population in the United States, and they are increasing in frequency year-to-year at an alarming rate. These findings demonstrate that overall rates of firearm injuries in the pediatric and adolescent populations have increased over the period of interest with most of the increase occurring in older children from assault with handguns. These data can hopefully help inform civic leaders, law enforcement officials, and legislators to design strategies to combat these areas of concern.

Significance: Analysis of specific groups, types of firearms, and mechanism of injuries will hopefully allow for risk stratification and future interventions. The findings of this study will hopefully provide insight on how best to initiate change and where to focus prevention strategies.

EPOS/POSNA Abstract Book (4)

OP-7

Loss of reduction in pediatric distal radius fractures: risk factors from a prospective multicenter registry

Apurva S. Shah, Zoe Elizabeth Belardo, Mark Leland Miller, Michael Willey, Susan T. Mahan, Divya Talwar, Rebecca Aguiar, Sana Bouajaj, Aspen Miller, Joshua Marino, Donald S. Bae, Pediatric Distal Radius Fracture Registry

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Therapeutic-Level II

Purpose: The purpose of this study was to report risk factors for loss of reduction of pediatric distal radius fractures from a large prospective multicenter cohort. We hypothesized that fractures with increased translation and angulation at the time of injury would be more likely to lose reduction.

Methods: Children aged 4–18 years old undergoing closed reduction for a displaced distal radius fracture and enrolled in the Pediatric Distal Radius Fracture (PDRF) Registry at four academic children’s hospitals were included. Children with open fractures, torus fractures, incomplete radiographs, or less than 4 weeks of follow-up were excluded. Radiographic loss of reduction (LOR) was defined as a change in angulation ≥10 degrees or an increase in translation greater than 50% of the radial width in any plane. Demographic, clinical, and radiographic variables were analyzed; bivariate analysis and multivariate logistic regressions were performed.

Results: In total, 616 children (69% male) were eligible with a mean age of 10.4 ± 3.4 years. Most subjects sustained bicortical distal radius fractures (68%), followed by Salter-Harris II physeal fractures (26%). The rate of radiographic LOR was 44% (271/616). LOR was more likely in patients <11 years old (54% versus 34%), in metaphyseal bicortical fractures compared to physeal fractures (53% versus 24%), when initial fracture translation exceeded 100%, and in patients with concomitant ulnar fracture (48% versus 27%) (all p < 0.001; Table 1). On multivariate analysis, metaphyseal bicortical radial fractures (odds ratio (OR) = 2.57), ≥51% translation on injury films (OR = 3.68), and non-anatomic closed reductions (OR = 3.00) significantly increased the odds of LOR. Ultimately, 47/616 children (8%) underwent secondary procedures, including repeat closed reduction or operative treatment. Children with self-identified White race (p < 0.001), increased pre-reduction translation (p = 0.002), and pre-reduction angulation (p = 0.013) were more likely to undergo a secondary procedure (Table 1). On multivariate analysis, non-anatomic closed reductions increased odds of secondary procedures (OR = 3.13), while self-identified Black race decreased these odds (OR = 0.16).

Conclusions: Bicortical metaphyseal fractures, ≥51% radial translation on pre-reduction films, and concomitant metaphyseal ulna fracture independently increase the odds of LOR for pediatric distal radius fractures. Patient body mass index (BMI) does not appear to influence LOR. Future investigations are warranted to study the relationships between LOR, secondary procedures, and patient race.

Significance: Orthopedic providers are advised that radiographic loss of reduction of ≥10 degrees is not uncommon for pediatric distal radius fractures. Bicortical fractures with ≥51% shaft width translation and concomitant ulna fracture should be closely monitored in clinic for LOR.

EPOS/POSNA Abstract Book (5)

OP-8

Modified elastic stable intramedullary nailing, a new approach for distal metaphyso-diaphyseal junction of forearm in children

Elie Georges Saliba, Pauline Savidan, Clement Munoz, Yan Lefèvre

Hopital Des Enfants CHU de Bordeaux, Bordeaux, France

LOE-Therapeutic-Level II

Purpose: Elastic stable intramedullary nailing (ESIN) is the treatment of choice for diaphyseal forearm fractures in children. However, when the fracture is located at the distal metaphyso-diaphyseal junction (DMDJ), the radial nail has only limited support on the distal fragment. This study aims to evaluate a modified ESIN method to treat these fractures.

Methods: The technique is initially carried out identically to a classic ESIN. Once its ascent is complete, the radial nail is moved back 4 cm and angled at 90° in its extra-osseous portion. The nail is then pushed back so that the entire angulated part penetrates the distal radius, increasing the pressure on the distal medial cortex. This has the effect of stabilizing the fracture in a perfectly aligned position. Between 2010 and 2015, 27 patients were included. Surgical treatment was accepted for fractures with an angulation greater than 20° and instability after reduction.

Results: Modified ESIN achieved a good and stable reduction of the fracture, with no displacement until late follow-up at 6 months.

Conclusions: This study confirms the feasibility and effectiveness of the modified ESIN technique as a treatment for these fractures.

Significance: Modified ESIN offers a new and reliable approach for DMDJ.

EPOS/POSNA Abstract Book (6)

OP-9

Take it or leave it: prevalence and complications from hardware removal following pediatric fracture fixation

Vineet Desai, Scott J. Mahon, Lucas Hauth, Amanda Pang, Apurva S. Shah, Jason Anari

The Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Therapeutic-Level IV

Purpose: Hardware removal (HR) is one of the most common surgical procedures in pediatric orthopedics. Surgeons advocate for HR for a variety of reasons, including to limit peri-implant fracture risk, native anatomy for adult reconstruction surgery, and to mitigate implant-related pain/irritation. To our knowledge, no recent study has investigated the characteristics and complications of HR in pediatric orthopedics. The goal of this study is to report the prevalence and complications of HRs across all pediatric fractures.

Methods: A retrospective case series was conducted of all HRs from 2014 to 2022 for patients who suffered a fracture requiring surgical intervention at a single urban tertiary care children’s hospital. Cases were identified using CPT codes/billing records. Spinal hardware and elective deformity correction hardware were excluded. Patient demographic and clinical data were recorded. For patients with multiple HRs, each case was recorded independently.

Results: Five hundred and fourteen HR cases for 478 patients met the study criteria. The median post-operative follow-up time was 1.58 weeks (interquartile range (IQR): 0.56–5.35). In total, 346 (67.3%) of the cohort were male. The mean age at HR was 12.05 (SD: 3.91), and the median BMI was 18.33 (IQR: 15.4–21.8). Pain (36.5%), surgeon preference/planned removal (36.1%), and parent/patient preference (14.6%) were the most common indications for HR. 85.4% of patients who underwent HR for pain experienced pain relief post-operatively. 50.4% cases were upper extremity while 49.6% were lower extremity. Flexible intramedullary nails (39.8%), single screws (39.5%), and compression plates with screws (15.2%) were the most common types of hardware removed. Fifty-seven (11.0%) of HRs had a complication. Seven (1.4%) cases had a surgical site infection. Seven (1.4%) cases had new, persistent pain after HR. Six (1.2%) cases had re-fracture (five forearm/wrist, one femur/knee). Of the forearm/wrist re-fracture cases, two occurred at prior fracture site, and three occurred adjacent to flexible intramedullary nail location. Six (1.2%) cases had incomplete HR (two syndesmosis screws, one distal tibia screw, one T-condylar screw, one supracondylar screw, one ulna flexible intramedullary nail). Four (0.8%) patients had hardware breakage while four (0.8%) had nerve palsy/injury (one each for radial, median, ulnar, and plantar nerves). Two (0.4%) patients suffered from a seroma/hematoma and one (0.2%) required re-operation.

Conclusions: HR following fracture fixation in pediatric orthopedics is associated with an overall complication rate of 11.0%.

Significance: Removal of hardware following semi-elective pediatric fracture surgery is not benign, and the 11% complication rate should be a part of the informed consent process.

EPOS/POSNA Abstract Book (7)

OP-10

Use of the bioabsorbable Activa IM-Nail™ in pediatric diaphyseal forearm fractures: a prospective cohort study with at least 1-year follow-up*

David Goettsche, Morten Jon Andersen

Copenhagen University Hospital—Herlev and Gentofte, Copenhagen Denmark

LOE-Therapeutic-Level IV

Purpose: Pediatric diaphyseal forearm fractures (PDFF) are very common injuries. Fractures needing surgery are most often treated with metal elastic stable intramedullary nails (ESIN). Metal nail removal is widely advocated; however, it is a burden on the child, the family, and healthcare economy. Bioabsorbable intramedullary nails (BIN) made from poly lactic-co-glycolic acid (PLGA) have been developed for some of the same indications as metal ESIN. The aim of this study was to evaluate the feasibility and safety of BIN (Activa IM-Nail™, Bioretec, Tampere, Finland) for PDFF.

Methods: From 1 May 2021 to 30 September 2022, children with unstable PDFF requiring surgery were sought to be prospectively and consecutively recruited. Surgical indications were complete fracture and displacement >50% of bone width or angulation >10° in any plane or irreducible or unstable after closed reduction. If consented, patients were operated with the Activa IM-Nail™ followed by 4 weeks of cast. Primary outcome was radiographic healing at 3 months assessed by the Radiographic Union Score (RUS). Secondary outcomes were pain, wound appearance, neurovascular status, bilateral elbow, forearm range of motion (ROM), fracture angulation and displacement, and any adverse device effects (ADE).

Results: In total, 27 children were eligible for inclusion and 9 children were excluded (2 declined participation, 6 fractures were reduced and casted, 1 had metal ESIN due to narrow intramedullary canal). Eighteen children were operated with BIN, 8 girls and 10 boys, mean age 10 years (4–14 years). Operating time was a mean of 66 (24–115) minutes. RUS was at least 8 at 3 months after surgery, 10 at 6 months, and 12 at 1 year. Three months after surgery, all patients had pain free and normal ROM. There were no serious adverse device effects (SADEs). Two children developed minor postoperative fracture angulation that did not require manipulation. One child sustained a non-displaced radius fracture 5 months after surgery and was treated in a cast. Another child sustained a displaced radius fracture more than 12 months after surgery and was treated with metal ESIN. One child with an open fracture had a pain free non-union and is awaiting further treatment.

Conclusions: The use of BIN showed results similar to metal ESIN. Three months after surgery, all, but one child, had solid healing and all children had pain free and normal ROM.

Significance: The use of BIN for PDFF is feasible, seems very safe, and eliminates the need for further surgery to remove implants.

*Indicates a presentation in which the Food and Drug Administration (FDA) has not cleared the drug and/or medical device for the use described (i.e. the drug or medical device is being discussed for an “off label” use.)

EPOS/POSNA Abstract Book (8)

OP-11

Biodegradable magnesium implants—a game changer in pediatric trauma care

Romy Marek, Tavishi Singh, Nicole Gabriele Sommer, Annelie-Martina Weinberg

Medical University of Graz, Graz, Austria

LOE-Not Applicable-Not Applicable

Purpose: What is needed to adequately treat pediatric fractures? A healthy and degradable implant material without harmful elements to overcome implant-related issues such as hypersensitivities or accumulation of metals in tissues. Another major advantage of degradable materials is the obviation of hardware removal after fracture healing. Hence, implantation through the active physis without affecting longitudinal bone growth, by using resorbable magnesium (Mg)-based implants, could broaden the spectrum of pediatric fracture treatment. Hence, the aim of the study was to investigate the local and systemic response of trans-epiphyseally implanted Mg-based ZX00 screws (Mg synthesized with <0.5 wt% Zn <0.5% Ca; l = 40 mm; d = 3.5 mm) on the active physis in a sheep model.

Methods: Three-month-old female, juvenile sheep (n = 8) underwent monocortical implantation with ZX00 through the epiphysis of the right tibia, whereas the left tibia was either implanted with a titanium (Ti) screw or was left untreated to serve as a control. In order to monitor ZX00 degradation and physis defects, in vivo clinical computed tomography (cCT) was performed at 3, 6, 12, 24, 52, 104, and 156 weeks post-surgery. All animals were sacrificed 180 weeks post-surgery. Tibiae and soft tissues were excised for further analysis. To quantitatively calculate the limb length difference (LLD) and physeal defect area, ex vivo high-resolution micro-computed tomography (µCT; 20 µm per voxel) was performed. Undecalcified tibiae with implants were embedded in Technovit for hard qualitative histology. To examine biocompatibility, organs were collected for soft tissue histology.

Results: First, we observed ZX00 screw breakage between 12 and 24 weeks post-surgery, resulting in ZX00 movement away from the physis, which additionally showed remarkable healing capacity, resulting in the absence of defect and axial deviation at 2 years. However, at 104 and 156 weeks post-surgery, Ti legs were significantly shorter (p < 0.05) when compared to ZX00 and Ctrl legs. In regard to biocompatibility, bone tissue did not show any signs of foreign body reactions or encapsulation. Moreover, qualitative assessment of histologically stained soft tissues did not reveal any harmful effect due to implantation and degradation.

Conclusions: These findings indicate the advantages of Mg-based implants for pediatric internal fracture fixation.

Significance: ZX00 implants are promising due to their biocompatibility and biodegradability, thereby minimizing complications, such as growth discrepancies, foreign body reactions, or encapsulations, making them superior for pediatric interventions.

OP-12

Biodegradable intramedullary nailing of severely displaced distal pediatric metaphyseal radius fractures

Marcell Benjamin Varga, Gergo Józsa, Zsófia Krupa, Tamás Kassai

Manninger Jenő Baleseti Központ, Budapest, Hungary

LOE-Therapeutic-Level II

Purpose: Severely displaced and shortened distal pediatric forearm fractures may require closed reduction. Many authors recommend osteosynthesis if the fracture remains unstable. The gold standard method is percutaneous pinning with Kirschner wires. K-wire-related complications like migration of the pins, superficial infections, and skin irritation are relatively frequent. We present the results of a prospective multicenter study comparing the K-wire technique and a new bioresorbable intramedullary nailing procedure.

Methods: We compared the results of K-wire osteosynthesis (KW groups) and biodegradable nailing (BR groups) of three Level I pediatric trauma centers. We compared the incidence of minor and major complications (superficial skin infection, tendon injury, nerve injury, secondary displacement, deep infection, skin irritation), differences in operative and radiation time, and unplanned medical check-up visits. Inclusion criteria were the clinical diagnosis of an unstable distal radial/forearm metaphyseal fracture with complete displacement, the presence of open growth plates, the child’s age under 14 years, and a minimal follow-up of 1 year.

Results: A total of 160 patients met the criteria indicated above (82 in the BR group, 78 in the KW group). No significant differences in age or right- or left-hand involvement were observed in either group. There was no significant difference between operative time. Radiation time was slightly reduced in the BR group. The number of minor complications was significantly reduced in the BR group. Secondary intervention (implant removal) was not necessary at all in the BR group, while in the KW group the K-wire had to be removed from all children. The number of unplanned medical examinations in the first 6 weeks was significantly lower in the BR group. After the 1-year follow-up, there was no difference in function between the two groups. Growth disturbance was not observed in either group after 1 year.

Conclusions: The biodegradable nailing technique eliminates the need for new implant removal interventions and reduces minor complications and the number of repeated, unplanned medical control examinations.

Significance: The paper is about a new alternative to a very common intervention. In addition to the health benefits, the absence of further intervention can also increase cost-effectiveness.

OP-13

Can scoliosis-specific exercises be performed with wearing brace in treating adolescent idiopathic scoliosis: an alternative use of scoliosis-specific exercises without sacrificing bracing hours

Charlene Fan, Michael To, Jason Cheung, Kenneth M.C. Cheung

The University of Hong Kong—Shenzhen Hospital, Shenzhen, People’s Republic of China

LOE-Therapeutic-Level I

Purpose: Bracing is the standardized care in treating progressive adolescent idiopathic scoliosis (AIS). Scoliosis-specific exercises (SSE), as an add-on to bracing treatment, show the promising effects in preventing curve progression. However, the general SSE is performed while patients take off the brace, which sacrifices the bracing hour that is a vital influencing factor of bracing success. Objective is to compare the difference between the SSE with wearing brace (SSE with brace-on), SSE without wearing brace (SSE with brace-off), and brace alone in preventing curve progression of AIS.

Methods: This was an assessor- and patient-blinded, randomized control trial with 4-year follow-up. One hundred and twenty patients undertaking Cheneau bracing treatment participated and randomly allocated into three groups: SSE with brace-on (group 1), SSE with brace-off (group 2), and brace-alone (group 3). SSE protocol was standardized with seven exercises with and without wearing the brace, 1.5 h/day for 5 days a week for patients in groups 1 and 2. Initial curve magnitude (Cobb angle at baseline before bracing treatment), in-brace correction, and the follow-up outcomes (Cobb angle without brace at every 6 months till skeletal maturity) were assessed by two surgeons blinded to this study. Exercise compliance and bracing compliance were monitored by tele questionnaire bi-weekly. Scoliosis Research Society 22-item questionnaire (SRS-22) was studied in addition to the changes of Cobb angle. Intention-to-treat (ITT) and per-protocol (PP) analyses were performed with mixed model analysis of variance (ANOVA).

Results: Patients showed no differences of initial curve magnitude, curve pattern, in-brace correction, and demographic characteristics between groups at baseline. Eighteen patients dropped out of this study; thus, outcomes of 102 patients were analyzed. The average bracing hour was highest in group 3 (group 1: 18 ± 2.2 h/d; group 2: 17 ± 3.8 h/d; group 3: 19 ± 0.6 h/d, p = 0.02). ITT analysis showed that the Cobb angle of the major curve, after brace weaned, was comparable between group 1 and group 2 (29° ± 5.4° versus 30° ± 3.6°, p > 0.05), yet was higher in group 3 (36° ± 7.8°, p < 0.01). PP analysis revealed that the highest reduction of Cobb angle was observed in group 2 (group 1: 27° ± 4.2°; group 2: 25° ± 5.3°; group 3: 33° ± 7.2°, p < 0.01), but the differences between group 1 and group 2 were within measurement error.

Conclusions: Bracing with SSE was better than bracing alone in treating progressive AIS. SSE performed with wearing brace was comparable to SSE performed without wearing brace in preventing curve progression.

Significance: Bracing with SSE shows promising effects in treating progressive AIS.

OP-14

Surgeon contoured versus pre-contoured patient-specific rods in adolescent idiopathic scoliosis: assessing global sagittal alignment

Sahir Jabbouri, Peter Joo, Wyatt David, Seongho Jeong, Jay Moran, Anshu Jonnalagadda, Dominick A. Tuason

Yale School of Medicine, New Haven, CT, USA

LOE-Therapeutic-Level III

Purpose: Surgery for adolescent idiopathic scoliosis (AIS) typically involves posterior spinal fusion (PSF) using rods contoured by the surgeon, which may be time-consuming and may not reliably restore optimal coronal and sagittal alignment. With the use of artificial intelligence (AI) and preoperative planning software to develop pre-contoured patient-specific rods, restoration of more optimal spinal alignment may be achieved. However, the literature lacks studies with a comparative group investigating outcomes of pre-contoured rods in AIS surgery.

Methods: This is a retrospective review of prospectively collected data of two consecutive groups of AIS patients who underwent PSF with surgeon contoured or patient-specific rods. Demographics, Lenke classification, fused levels, osteotomies, estimated blood loss (EBL), surgical time, and last follow-up Scoliosis Research Society (SRS)-22 scores were obtained via chart review. Radiographic measurements including coronal Cobb angle, T5-T12 thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch, and T1 pelvic angle (TPA) were obtained pre-operatively, postoperatively, and at last follow-up. Patients were excluded if follow-up was less than 6 months. Adaptive spine intelligence software was utilized to predict post-operative sagittal alignment which was compared with observed measurements. Student’s and paired t-tests were performed to determine significant mean differences for continuous variables and chi-square for categorical variables.

Results: Thirty-six patients in the surgeon contoured cohort (average last follow-up = 11.3 months) and 22 in the pre-contoured cohort (average last follow-up = 9.7 months) were included. No significant differences were noted with regard to demographics, Lenke classification, preoperative radiographic measurements, number of fused levels and osteotomies, EBL, surgical time, and overall total SRS-22 scores at last follow-up. TK was between 20 and 40 degrees in 95.5% of patients with pre-contoured rods versus 61.1% of patients with surgeon contoured rods at last follow-up (p = 0.004). PI-LL mismatch was within 10 degrees postoperatively in 72.7% of patients in the pre-contoured cohort versus 33.3% of patients in the surgeon contoured cohort (p = 0.004). Other radiographic measurements were similar. Average differences between AI predicted and observed values for the PC group were 3.7 for TK (p = 0.005), 8.7 for LL (p < 0.001), −7.6 for PI-LL mismatch (p = 0.002), and −2.6 for TPA (p = 0.112).

Conclusions: AI and pre-contoured rods help achieve global sagittal balance with excellent accuracy and notably improved kyphosis restoration and PI-LL mismatch than surgeon contoured rods in AIS patients.

Significance: Patient-specific pre-contoured rods help achieve more optimal global sagittal balance than surgeon contoured rods in AIS.

EPOS/POSNA Abstract Book (9)

OP-15

Pulmonary function at minimum 10 years after segmental pedicle screw instrumentation for thoracic adolescent idiopathic scoliosis

Linda Helenius, Matti Mikael Ahonen, Johanna Syvänen, Ilkka J. Helenius

Helsinki University Hospital, Helsinki, Finland

LOE-Therapeutic-Level II

Purpose: Adolescent idiopathic scoliosis (AIS) with thoracic curves is associated with reduced pulmonary function preoperatively. It remains unclear how much pulmonary improvement can be obtained using pedicle screw instrumentation at long-term follow-up.

Methods: Out of 64 consecutively surgically treated patients with thoracic AIS (Lenke 1-4, 6) using pedicle screw instrumentation, 50 (mean age at surgery 14.7 ± 1.9 years, 44 females) participated in a prospective 10-year follow-up study (mean FU, 12.2 years). Preoperative major curve averaged 57° (SD, 8.5°) with a remaining curve of 15° (SD, 6.3°) at 10-year follow-up. They were evaluated using clinical examination, spinal radiographs, and spirometry preoperatively and at 10-year follow-up. The preoperative percentage predicted values were adjusted for the height loss caused by the scoliosis according to curve size.

Results: Preoperatively, 49% (20/41) had forced vital capacity (FVC) or forced expiratory volume in one second (FEV1) below 80% of the predicted normal values representing pulmonary function impairment. FVC improved from preoperative 3.29 L (SD, 0.78 L) to 3.87 L (0.79 L) at 10-year follow-up (p < 0.001). This improvement averaged 510 mL (SD, 560 mL) in patients having both preoperative and 10-year follow-up measurements available. The percentage predicted values for FVC showed an improvement from 83% preoperatively to 86% at 10-year follow-up (p = 0.048). At 10-year follow-up, 38% (19/50) of the patients had FVC or FEV1 below 80% of the predicted values.

Conclusions: Lung volumes improved by a mean of 510 mL from preoperative to 10-year follow-up in patients undergoing pedicle screw instrumentation for thoracic AIS. Despite improvement of absolute values, one-third of the patients fulfilled the criteria for pulmonary function impairment at 10-year follow-up.

Significance: Preoperatively, 49% of the AIS patients with thoracic curves showed impairment in pulmonary function. After surgical correction of the scoliosis and a 10-year follow-up, 38% still fulfill the criteria for restrictive lung disease.

EPOS/POSNA Abstract Book (10)

OP-16

Osteotomies at the time of graduation surgery: how much do we get from them?

Tyler A. Tetreault, Tiffany Phan, Tishya A.L. Wren, Michael J. Heffernan, John B. Emans, Lawrence I. Karlin, Amer F. Samdani, Michael G. Vitale, Ilkka J. Helenius, Lindsay Andras, Pediatric Spine Study Group

Children’s Hospital Los Angeles, Los Angeles, CA, USA

LOE-Therapeutic-Level III

Purpose: Following growing instrumentation for early-onset scoliosis (EOS), patients often undergo PCO at the time of conversion to definitive fusion. Their efficacy may be limited following prior instrumentation. Our purpose was to determine whether PCO at the time of conversion to definitive fusion in EOS graduates impacts outcomes.

Methods: Patients from a multicenter database undergoing growing rod instrumentation conversion to definitive fusion were grouped by those that did or did not have PCO. Patients with inadequate radiographs, <2 years of follow-up, or three-column osteotomies at the time of fusion were excluded.

Results: A total of 839 EOS patients who underwent conversion to definitive fusion met the inclusion criteria. In total, 176 (21%) patients had PCOs and 663 (79%) did not. The age at index surgery was younger (6.6 versus 7.4 years, p = 0.0009) and the mean duration of growing instrumentation was greater (6.1 versus 5.5 years, p = 0.009) in the PCO group. Prior to fusion, curve magnitude was similar between the groups (PCO = 61.9 degrees, no PCO = 59.3 degrees, p = 0.18). For the PCO group, on average, 4.4 osteotomies (range: 1–12) were performed. EBL (PCO = 821 cc versus no PCO = 752 cc, p < 0.01) and surgical time (PCO = 403 min versus no PCO = 348 min, p < 0.01) were greater in the PCO group. Postoperatively, mean major curve magnitude and curve correction were similar between the two groups (mean correction PCO = 16.5, no PCO = 14.4 degrees, p = 0.19). However, accounting for preoperative curve magnitude, there was a relationship between number of PCOs and curve correction (p = 0.04). Mean correction was 14.2 degrees with 1–4 osteotomies, 19.0 degrees with 5–8 osteotomies, and 23.9 degrees with 9–12 osteotomies. Overall, mean correction per osteotomy was 4.5 degrees. There was no relationship between degrees of correction per osteotomy and duration of instrumentation prior to conversion (p = 0.12). Postoperative complications at 2 years were similar between groups (PCO = 25% versus no PCO = 27%, p = 0.63).

Conclusions: EOS graduates achieved minimal correction at the time of conversion regardless of whether PCOs were performed. PCOs were associated with increased EBL and operative time, but similar complication rate. More PCOs resulted in more correction, albeit <10 degrees/osteotomy anticipated in a previously uninstrumented spine.

Significance: PCOs at the time of conversion to fusion in growing rod graduates resulted in less than half of the correction reported in previously uninstrumented spines.

OP-17

Is bracing after completion of Mehta casting worthwhile?

Tiffany Thompson, Carlos Monroig-Rivera, Mike (M) O’Sullivan, Charles E. Johnston

Scottish Rite for Children, Dallas, TX, USA

LOE-Therapeutic-Not Applicable

Purpose: Following Mehta cast treatment for idiopathic early-onset scoliosis (IEOS), there is no consensus on the value of continued orthotic management, specifically regarding preventing progression. We wished to compare outcomes for patients treated with a brace following cast discontinuation compared to those who were simply observed.

Methods: From a single institution database of IEOS patients treated by casting, we identified 73 patients treated initially by Mehta casts. At completion of the casting program, patients were either observed or prescribed a thoracolumbar sacral orthosis (TLSO) to continue non-operative treatment, at the discretion of the treating physician. We recorded patient demographics, cast details and length of treatment, and curve magnitudes at time points pre-cast, at cast discontinuance, and at last follow-up or until another form of treatment was initiated. We hypothesized that patients doing braces post-casting would achieve/maintain better curve control long term. Bracing was defined “successful” if no other treatment was required.

Results: Seventy-three patients with mean age of 22.2 months (7–62 months) at cast initiation were studied. Five patients underwent surgery after cast discontinuance. Twelve patients with initial mean curve of 36° (17°–70°) were corrected to 16.1° (1°–41°) after final cast and then observed. Fifty-six patients with mean curve of 46° (21°–89°) at initiation were corrected to 28° (1°–79°) at cast discontinuance and then prescribed a TLSO which was worn for a mean of 5.8 years (0–15 years). At last follow-up, 44 braced cases were considered “success” (79%) with mean curve of 19.4°, while 12 braced cases failed with curves measuring 48°, and further treatment (11 surgery, 1 re-cast) needed. Braces were discontinued in 25 patients with 16 remaining stable (no progression, mean curve 13.5°) and 9 progressing 15°, while 14/19 continuing bracing remained stable. One of 12 observed patients compared to 11/56 braced patients required surgery.

Conclusions: Bracing following cast treatment for IEOS was nearly 80% successful in avoiding further treatment even though curves at cast discontinuance were larger (28 versus 16) compared to observed cases.

Significance: When cast treatment does not achieve correction <20°, continuing treatment with a brace appears to have benefit in avoiding surgery.

OP-18

Limited fusion for congenital scoliosis: is it truly one and done?

Brandon Yoshida, Tyler A. Tetreault, Luke Christian Drake, Tiffany Phan, Jacquelyn Nicole Valenzuela-Moss, Tishya A. L. Wren, Lindsay Andras, Michael J. Heffernan

Children’s Hospital Los Angeles, Los Angeles, CA, USA

LOE-Therapeutic-Level III

Purpose: Limited spinal fusion is a common surgical strategy in the treatment of congenital scoliosis. Due to the heterogeneity of deformity and treatment strategies, long-term outcomes, including the need for additional surgery, are poorly understood. The purpose of the study was to understand the rate and risk factors for reoperation following limited fusion for congenital scoliosis.

Methods: A single-center retrospective review of congenital scoliosis patients who were initially treated with a limited instrumented fusion was conducted. Curve progression, short and long-term complications, and need for additional spinal surgery were assessed. Risk factors for additional surgery were compared between patients who underwent additional surgery and patients who did not require additional surgery.

Results: Thirty-six patients underwent limited instrumented fusion at an average age of 5 years (SD: 2.5 years). The mean number of levels fused was 3.5 (SD: 1.3). Index surgery location included cervical (6%), thoracic (64%), thoracolumbar (50%), lumbar (42%), and lumbosacral (11%). Seven (19.4%) of the patients had two areas of fusion (separated by unfused segments) treated at the index procedure. Average follow-up was 7.6 years (range: 2.2–14.1, SD: 3.4). Average curve magnitude improved from 50° to 26°, with a mean improvement of 18° (range: 11.6°–23.9°, SD: 18°, p < 0.0001). Nineteen patients (53%) required reoperation at a mean of 5.2 years. The mean number of additional surgeries was 3.6 (SD: 3.4). Preoperative curve magnitude was greater in patients who had reoperation compared to patients who did not require reoperation (62 ± 4.9 versus 38 ± 4.7, p = 0.002). Age at index surgery, medical comorbidities, if all congenital anomalies were addressed during index procedure, number of levels fused, location of the index procedure, and postoperative curve magnitude did not differ between groups (Table 1).

Conclusions: Limited fusion for congenital scoliosis resulted in a 53% reoperation rate at a mean of 5.2 years. Preoperative curve magnitude was associated with reoperation, while age, location, number of levels fused, and addressing all congenital anomalies at the index procedure did not differ between groups. These results suggest that surgeons should consider intervention at smaller curve magnitudes in patients with congenital scoliosis and counsel families that a one and done procedure is less likely with larger curves.

Significance: The results of this study suggest that limited fusion should be considered prior to significant curve progression in patients with congenital scoliosis to minimize the need for additional surgery.

EPOS/POSNA Abstract Book (11)

OP-19

Greater implant density does not improve pelvic obliquity and major curve correction in neuromuscular scoliosis

Patrick Thornley, Arlene R. Maheu, Kenneth Rogers, Paul D. Sponseller, Peter O. Newton, A. Noelle Larson, Joshua Pahys, Peter G. Gabos, M. Wade Shrader, Tracey P. Bastrom, Suken A. Shah, Harms Study Group

Nemours Children’s Health, Wilmington, DE, USA

LOE-Therapeutic-Level II

Purpose: Neuromuscular scoliosis (NMS) is the second most prevalent pediatric scoliosis etiology. The NMS population present unique challenges with larger curves and associated pelvic obliquity (PO), osteopenia, and greater comorbidities. The influence of implant density (ID) has undergone much investigation in the adolescent idiopathic scoliosis literature. These investigations have shown no significant difference in correction between low and high ID cohorts. It is however unknown how ID affects initial and long-term correction in NMS. We hypothesized that greater ID in posterior instrumented fusions (PIF) to the pelvis in NMS patients will achieve better coronal and sagittal correction with long-term durability.

Methods: A retrospective review of a prospectively collected multicenter NMS registry database was performed. All NMS patients undergoing upper thoracic to pelvis PIF with a minimum follow-up of 2 years were included. ID was defined as the number of screws per level fused. Patients were divided into three groups: low density (LD; ≤1.3 screws/level), medium density (MD; ≥1.3 and ≤1.6 screws/level), and high density (HD; ≥1.6 screws/level). Demographic and radiographic data were collected to perform independent sample t-tests and cluster analysis for correlation.

Results: A total of 235 patients (56 LD, 84 MD, 95 HD) were included. Baseline demographic characteristics were similar between cohorts including CPChild scores. There were mild preoperative major Cobb angle differences with no difference in PO (Table). Perioperative data was comparable between groups, with significantly increased operative times with higher ID (p < 0.001) (Table). Two-year postoperative coronal plane and PO corrections demonstrated no between-group difference in correction regardless of ID (Table). Sagittal plane measurements demonstrated no statistically significant difference between groups at all time points. Similarly, no functional outcome differences as measured by CPChild were present at any time point in either group (Table).

Conclusions: Lower ID in NMS demonstrates comparable major curve correction and PO correction to higher ID constructs at 2 years postoperatively with reduced operative time and equivalent functional outcomes.

Significance: Efforts to maximize balanced corrections achieve improved sitting balance, while minimizing operative time, complications, and cost are imperative in NMS management. Lower ID should be considered in neuromuscular scoliosis correction as both an effective surgical strategy and a potential source of significant cost reduction.

EPOS/POSNA Abstract Book (12)

OP-20

The effect of traction and spinal cord morphology on intraoperative neuromonitoring alerts

Evan Fene, Lydia Klinkerman, Charles E. Johnston, Jaysson T. Brooks, Megan Johnson

Scottish Rite for Children, Dallas, TX, USA

LOE-Prognostic-Level II

Purpose: Patients with type 3 spinal cords are at greater risk for intraoperative neuromonitoring (IONM) alerts when undergoing thoracic scoliosis correction. The use of intraoperative traction during deformity correction is also associated with an increased risk of IONM alerts. The purpose of this study is to examine the interplay between spinal cord morphology and intraoperative traction.

Methods: An institutional review board (IRB)-approved retrospective review of patients with major thoracic curves ≥70° who underwent spinal fusion from 2016 to 2022 at a single institution were reviewed. Patients without a preoperative magnetic resonance imaging (MRI) were excluded, yielding 102 patients for review. Spinal cord morphology was determined by consensus of four observers using the criteria by Sielatycki et al.

Results: Seventy-five (73.5%) patients were female, with an average age of 13.7 ± 2 years at surgery. Mean thoracic Cobb was 85° ± 13°. The average number of levels fused was 12 ± 1.5, implant density 1.5 ± 0.3, estimated blood loss (EBL) 895 ± 645 mL, and total surgical time 314 ± 112 min. Eighty-seven patients had posterior spinal fusion (PSF), while 15 had an anterior spinal fusion (ASF)/PSF. Intraoperatively, traction was used in 15 patients. Sixteen patients had type 1 cords, 71 type 2, and 15 type 3. Seventeen patients had an IONM alert and surgery was aborted in three patients due to persistent loss of IONM. Patients with type 3 cords were more likely to have an IONM alert than those with type 2 cords (46.7% versus 14.1%, odds ratio (OR) = 5.3, p = 0.004). One hundred percent of patients with type 3 cords placed in traction intraoperatively had an IONM alerts versus 20% without traction (p = 0.007). Multivariate regression found cord type (OR = 6.3, p = 0.02) and intraoperative traction (OR = 8.9, p = 0.02) to be significant risk factors for an IONM alert.

Conclusions: Type 2 and 3 spinal cords are found in 84% of patients with curves ≥70°. An IONM alert is six times more likely in patients with type 3 cord. Patients with a type 2 or type 3 cord are nine times more likely to have an IONM alert when traction is used intraoperatively and 100% of patients with a type 3 cord and intraoperative traction in this cohort experienced an IONM alert.

Significance: The use of intraoperative traction should be carefully considered in patients with a thoracic curve ≥70°, especially if a preoperative MRI demonstrates type 3 cord morphology.

OP-21

What kind of kyphosis? Stratifying thoracolumbar kyphosis in achondroplasia

Luiz Carlos Almeida Da Silva, Yusuke Hori, Colleen P. Ditro, Kenneth Rogers, J. Richard Bowen, William G. Mackenzie, Stuart Mackenzie

Nemours Children’s Hospital—Delaware, Wilmington, DE, USA

LOE-Therapeutic-Level IV

Purpose: When treating thoracolumbar kyphosis (TLK) in children with achondroplasia, predicting outcomes, correction, and surgical complications is essential. There is limited literature clearly describing the treatment and risk profiles among different types of TLK. This study aimed to classify deformities of the thoracolumbar junction, describe effective operative treatment, and compare surgical complications.

Methods: A single-center retrospective review at a quaternary referral center was performed from 2004 to 2021. Inclusion criteria consisted of achondroplasia diagnosis, TLK, symptomatic spinal stenosis, surgical treatment, and at least 1 year of follow-up. Patient demographics, clinical notes, and radiographs were analyzed. Post-operative complications were classified by Clavien-Dindo System (CDS). Intra-observer reliability was measured with Cohen’s kappa coefficient, and interobserver reliability with Fleiss’ kappa coefficient.

Results: Forty patients with achondroplasia and TLK requiring surgical spinal decompression and fusion were treated at an average age of 16 ± 5 years, with a mean follow-up of 5 ± 4 years. We identified four classes of patients: Class 1 involves gradual multi-level TLK with diffuse stenosis; Class 2 involves severe focal TLK associated with apical vertebral body wedging and localized stenosis, with a flattened or lordotic thoracic spine above; Class 3 involves severe post-laminectomy kyphosis; and Class 4 is a heterogeneous group with additional diagnoses related to TLK. The intra-observer kappa index of this classification was 0.90 (p < 0.001), and the inter-observer was 0.83 (p < 0.001). The Class 1 patients were treated with posterior spinal decompression and fusion (PSDF), while all others required a combination of PSDF, anterior spinal fusion, and posterior spinal osteotomies. Kyphosis correction rate averaged 81%, with 52.5% (21/40) rate of intraoperative complication. Class 1 patients had shorter surgical times and lowered estimated blood losses (Table 1). Classes 3 and 4 presented more major complications when compared to classes 1 and 2 (p = 0.45).

Conclusions: Treatment of TLK and symptomatic spinal stenosis in patients with achondroplasia can involve complex correction techniques and has a high rate of complication. Surgical options and risk can be stratified based on this reliable TLK classification system. With improved communication and preoperative planning, patients with achondroplasia and TLK can be successfully managed with excellent correction and managed risk.

Significance: This novel classification of TLK in achondroplasia has high inter-observer reliability and can help surgeons better educate and treat these challenging patients.

EPOS/POSNA Abstract Book (13)

OP-22

Distribution of curve flexibility in idiopathic scoliosis—a descriptive study

Simon Blanchard, Matan Malka, Ritt Givens, Michael G. Vitale, Benjamin D. Roye

New York-Presbyterian Morgan Stanley Children’s Hospital, New York, NY, USA

LOE-Prognostic-Level II

Purpose: Curve flexibility is an important variable for adolescent idiopathic scoliosis (AIS) outcomes. This study sought to determine the distribution of flexibility in a multicenter AIS cohort and investigate associated characteristics. It was hypothesized that flexibility would be normally distributed and would correlate with patient characteristics such as body mass index (BMI), curve pattern, and skeletal maturity.

Methods: Surgical AIS patients enrolled in a Harms Study Group (HSG) center were included. Flexibility was measured using lateral bending radiographs. The distribution was graphed using SPSS, and the relationship between flexibility and other parameters was assessed using t and chi-square tests. Pearson’s R was used for regression analysis.

Results: A total of 4574 patients (mean age: 14.5 ± 2.2 years, 80.5% female) met the inclusion criteria. Mean flexibility was 72.0% ± 11.6%. Both primary thoracic (Lenke 1 + 2, N = 2895) and primary lumbar curves (Lenke 5 + 6, N = 1030) followed a normal distribution. Mean thoracic curve flexibility was significantly higher than primary lumbar curve flexibility (71.4% versus 68.98%, p < 0.001). Flexibility was inversely correlated with both higher age (p = 0.002) and increased skeletal maturity (p = 0.003). Patients who have a healthy weight had more flexible curves than those who were overweight (p = 0.019). Interestingly, and unanticipated, better Scoliosis Research Society (SRS)-22 and SRS-24 scores were associated with lower flexibility (p < 0.03, p < 0.01). Not associated with curve flexibility were sex (p = 0.124), weight (p = 0.536), and height (p = 0.121). Surprisingly, thoracic curves were more flexible than lumbar curves (p < 0.001). Increased BMI was associated with decreased flexibility in thoracic curves (p < 0.001), but not with lumbar curves (p = 0.963). In addition, for thoracic curves, those with a lumbar A modifier were significantly more flexible than B (p < 0.001) and C (p < 0.001) types. For sagittal parameters, normo-kyphotic and hypo-kyphotic curves were more flexible than hyperkyphotic curves (p = 0.001).

Conclusions: Flexibility follows a normal distribution in AIS patients, as shown in the attached figure. Older, more skeletally mature patients had less flexibility. Interestingly, thoracic curves were more flexible than lumbar curves, and only thoracic flexibility varied with BMI. In addition, higher SRS scores were associated with less flexible curves.

Significance: This study describes a normal distribution of flexibility in a large population of surgical AIS patients. It also confirms previously described relationships between flexibility and various patient characteristics (age, maturity, BMI) with a significantly larger sample size than previous studies, as well as describing several new factors that correlate with curve flexibility.

EPOS/POSNA Abstract Book (14)

OP-23

When is growth greatest? Spine and total body growth in idiopathic scoliosis through Sanders maturation stages 2, 3A, 3B, and 4

Yusuke Hori, Bryan Menapace, Burak Kaymaz, Luiz Carlos Almeida Da Silva, Norihiro Isogai, Sadettin Ciftci, Kenneth Rogers, Petya Yorgova, Andrea Mary Elsby, Peter G. Gabos, Suken A. Shah

Nemours Children’s Hospital, Wilmington, DE, USA

LOE-Prognostic-Level III

Purpose: The ability to accurately predict growth is crucial in treating the growing spine. The Sanders Maturation Stage (SMS) 2–4 represents periods of rapid growth and are key stages for growth modulation surgery. A detailed assessment of spine growth during these stages is imperative and is lacking. This study aimed to evaluate the spine and total body height growth through SMS 2, 3A, 3B, and 4 and to assess scoliosis progression during this period.

Methods: In this single-center retrospective case-control study, consecutive patients with idiopathic scoliosis staged SMS 2–4 were analyzed from January 2013 to December 2022. T1-S1 spine height, total body height, and curve magnitude were measured at each visit. Spine and total body height velocity and curve progression rate were assessed between the initial and first follow-up visit (6–12 months). For those observed until skeletal maturity (Risser 4+ or 5), height gain and curve progression were evaluated. Considering height loss due to scoliosis, spine and total body height were corrected for curve magnitude using validated formulas. For statistical comparisons between the groups, the Kruskal–Wallis test was used, followed by Bonferroni post hoc analysis.

Results: The study included 525 patients (68% girls, mean age: 12.4 ± 1.4) and 2082 radiographs. Spine height velocity peaked during SMS 3A (2.6 ± 0.8 mm/month), being approximately 1.3 times that of SMS 2 (2.0 ± 0.9 mm/month), 1.5 times that of SMS 3B (1.7 ± 0.6 mm/month), and 1.7 times that of SMS4 (1.5 ± 0.7 mm/month) (Figure 1a). SMS 2 and SMS 3A had comparable total body height velocities (6.3 ± 2.2 mm/month; 6.4 ± 1.7 mm/month, respectively), both surpassing SMS 3B (4.8 ± 2.0 mm/month) and SMS 4 (3.5 ± 1.6 mm/month) (Figure 1b). Curve progression rates were consistent across the subtypes. Among those observed until skeletal maturity, SMS 2 had the highest spine and total body height gains, with declines noted as SMS advanced. Curve progression was greatest in SMS 2 (16° ± 14°), followed by SMS 3A (11° ± 12°), with SMS 3B and SMS 4 being similar (7° ± 9°; 6° ± 9°, respectively) (Figure 2).

Conclusions: This investigation revealed the spine grows fastest during SMS 3A and suggests that leg growth peaks at SMS 2. SMS 2 demonstrated the highest potential for both spine and total body height growth, as well as curve progression. These insights are crucial for determining intervention timing in scoliosis treatment, including decisions on bracing, surgery, and selecting between fusion or growth modulation.

Significance: This study identifies the pivotal SMS where spine and leg growth peak, facilitating more precise timing of treatment in idiopathic scoliosis and potentially guiding more successful outcomes.

EPOS/POSNA Abstract Book (15)

OP-24

The true cost of late referral in adolescent idiopathic scoliosis: a 5-year follow-up study

Emma Nadler, Jennifer Dermott, Dorothy Kim, David E. Lebel

Hospital for Sick Children, Toronto, ON, Canada

LOE-Economic-Level III

Purpose: Bracing moderate curvatures in skeletally immature idiopathic scoliosis patients is known to minimize the risk of curve progression to surgical range. Unfortunately, late referrals are common with more patients presenting as surgical versus ideal brace candidates. This study analyzes the total treatment cost differential between adolescent idiopathic scoliosis (AIS) patients who at initial consultation are ideal brace candidates versus late referrals.

Methods: This is a retrospective review and cost analysis of AIS patients seen for initial consultation in 2014 who were either a late referral or an ideal brace candidate. Late referrals were defined as 50+° curvatures or over 40° and ≤Risser 2. Ideal brace candidates were defined as 25°–40° curves, ≤Risser 2. Patient medical records were reviewed to determine progression in brace candidates to surgical range, up to 5 years after initial visit or time. Total costs assumed all curves 50+° would at some point have surgery. In addition to the cost of a brace or a surgical procedure, total treatment costs considered typical number of clinic visits (including associated travel, parking, meals, and loss of income costs for family) and spine X-rays obtained.

Results: Within this cohort, 63 patients met ideal brace indications (17%) compared to 103 patients considered late referral (28%) (Scenario 1). The average total cost per patient for brace treatment was calculated at $13,459 versus $68,009 for surgical treatment. Within the 5-year study period, 10 ideal brace candidates progressed to 50+° curvatures and 5 were lost to follow-up. In 2014, the theoretical total cost for ideal brace candidates was $1,868,052 versus $700,492 for late referrals (Scenario 1). If the late referrals seen that year were instead seen as ideal brace candidates, the total cost of treatment, including surgical costs for patients expected to progress despite brace treatment, would be $4,954,554, a cost savings of $3,918,373.

Conclusions: The total treatment cost of a late AIS referral is 56% more than the treatment cost of an ideal brace candidate. Early diagnosis and treatment are significantly more cost-effective.

Significance: These findings underscore the financial consequences of late AIS diagnosis, emphasizing the need for early detection to reduce the cost burden. It is expected that the cost differential is underestimated as longer than recommended wait times, if applicable, and the inherent re-operation rate are not considered.

EPOS/POSNA Abstract Book (16)

OP-25

Battle of the braces: a comparison of brace efficacy in patients with adolescent idiopathic scoliosis treated with Providence, Boston-style, and Rigo-Cheneau braces

Leigh Davis, Amy Bridges, Julie Hantak, Hilary Harris, Sofie-Ellen Stroeva, Nikolay Braykov, Afrin Jahan, Nicholas D. Fletcher

Children’s Healthcare of Atlanta, Atlanta, GA, USA

LOE-Therapeutic-Level IV

Purpose: A variety of brace options exist for the management of adolescent idiopathic scoliosis (AIS). While institutional or surgeon’s preferences abound, there is sparse literature comparing brace efficacy.

Methods: A retrospective review of patients aged 10–18 with AIS of 20°–45° who were Risser 0–2 at initiation of treatment treated at a single center using a single orthotics team was performed. Patients were included if they had either completed brace treatment AND had a minimum of 6-month out of brace follow-up OR had undergone surgery. Brace success was defined as curve progression <6 degrees without the need for surgery. Patients were treated with a Providence nighttime brace (PNB), Boston-style TLSO (BB), or Rigo-Cheneau (RC) custom brace. Brace wear was determined by the treating physician.

Results: Patients treated with 32 PNB, 37 BB, and 30 RC braces met all inclusion criteria. Overall, 44 patients (44%) progressed >6° and 18 patients (18 %) progressed to surgery. Eighty-eight percent were female, with an average age at brace initiation of 12.0 years. Sixty-two percent of females were premenarchal at the onset of bracing, 66% were Risser 0, and 34% Risser 1 or 2. Thoracic, thoracolumbar, and lumbar curves averaged 27° ± 7°, 28° ± 6°, and 26° ± 6° at initiation. Thoracic curve correction was 46% ± 34% compared to thoracolumbar curves 73% ± 36%. PB were worn at nighttime only (8–10 h) while BB and RC were worn for part of the day and night. Twenty-seven percent of patients treated with a BB progressed to surgery compared to 13% of RC and 13% of PNB patients (p = 0.21). Among Risser 0 patients, 37% of BB patients progressed to surgery compared to 11% of RC (p = 0.07) and 10% of PNB patients (p = 0.03). Similar trends toward less efficacy in patients with BB were seen using curve magnitude increase >6°; however, these did not meet statistical significance. Multivariate regression analysis found that skeletally immature (R0) patients treated with a BB had a 5.6-fold higher risk of surgery than RC or PNB (p = 0.04) and a 2.8-fold higher risk of curve progression (p = 0.09). This difference was not seen in Risser 1 or 2 patients.

Conclusions: Skeletally immature patients (Risser 0) treated with a Boston brace were nearly six times more likely to require surgery compared to those treated with a Rigo-Chenault or Providence brace. Patients who were Risser 1 or 2 were successfully treated in any of the three braces.

Significance: Rigo-Chenault and Providence bracing were more successful than Boston braces for skeletally immature patients with AIS.

EPOS/POSNA Abstract Book (17)

OP-26

Improvement in axial rotation with bracing reduces risk of curve progression in patients with adolescent idiopathic scoliosis

Michael Fields, Christina Carin Rymond, Matan Malka, Ritt Givens, Matthew E. Simhon, Hiroko Matsumoto, Gerard F. Marciano, Afrain Z. Boby, Benjamin D. Roye, Michael G. Vitale

Children’s Hospital of New York, New York, NY, USA

LOE-Therapeutic-Level II

Purpose: While in-brace coronal plane correction is commonly used as a proxy for brace efficacy, emerging evidence supports the importance of three-dimensional (3D) in-brace correction for adolescent idiopathic scoliosis (AIS) patients. This study investigated the relationship between axial plane parameters and treatment failure in patients at a single center undergoing brace treatment for AIS. We hypothesize that AIS patients with large in-brace axial vertebral rotation (AVR) and/or poor improvement in AVR with bracing would have increased risk of treatment failure.

Methods: AIS patients (Sanders 1–5) undergoing Rigo-Chêneau bracing at a single institution were included. AVR was determined by utilizing pre-brace and in-brace (3D) spinal reconstructions based on biplanar low-dose EOS® radiographs. The primary outcome was treatment failure defined as coronal curve progression >5°. Minimum follow-up was 2 years.

Results: Seventy-five patients (61/75, 81% female) were included in the final cohort. Mean age at bracing initiation was 12.8 ± 1.3 years and patients had a pre-brace major curve of 31.0°°± 6.5°. Twenty-five (33%; six males, 19 females) patients experienced curve progression >5°, and 18/25 required surgical intervention. The treatment failure group had larger in-brace absolute AVR than the success group (5.8°± 4.1° versus 9.9°± 7.6°, p = 0.003), but also larger initial coronal curve measures. The magnitude of in-brace AVR did not appear to be associated with treatment failure after adjusting for pre-brace major curve (hazard ratio (HR): 0.99, 95% confidence interval (CI): 0.94–1.05, p = 0.833). After adjusting for pre-brace major coronal curve, patients with improvement of AVR with bracing had an 85% risk reduction in treatment failure versus those without improvement (HR: 0.15, 95% CI: 0.02–1.13, p = 0.066). At final follow-up, 42/50 (84%) patients who did not progress had a Sanders ≥7.

Conclusions: While absolute in-brace rotation was not an independent predictor of curve progression (due to its correlation with curve magnitude), improved AVR with bracing was a significant predictor of curve progression.

Significance: This study is the first step toward investigating the interplay between 3D parameters, skeletal maturity, compliance, and brace efficacy, setting the stage for a future prospective multi-center study with adequate design and power.

EPOS/POSNA Abstract Book (18)

OP-27

PROMIS-based assessment of brace compliance

Carlos Monroig-Rivera, David C. Thornberg, Chan-Hee Jo, Megan Johnson

Scottish Rite for Children, Dallas, TX, USA

LOE-Not Applicable-Level III

Purpose: Bracing is the primary non-surgical treatment for patients with idiopathic scoliosis (IS). While the TLSO brace remains the gold standard of treatment, Rigo-Cheneau (RC) and Providence (PROV) nighttime braces are being used more often due to a perceived increased level of comfort/ease of wear. The goal of this study was to examine compliance rates and patient-reported outcomes (PROs) for each type of brace.

Methods: Retrospective review of patients treated in a brace for IS at a single institution from 2021 to 2023. Patients with compliance data, pre-treatment PROMIS scores, and post-treatment PROMIS scores were included. Those with prior treatment (casting, bracing) or non-idiopathic etiologies were excluded.

Results: One hundred and twenty-seven patients were identified, of whom 95 (78%) were female. Eighty patients were treated with a TLSO and 47 with a PROV. The average compliance rate was 83% and was higher for PROV (84%) than for TLSO (70%, p = 0.03). Patients who were noncompliant with bracing (<80%) had worse PROMIS anxiety scores than those who were compliant (41 versus 37, p = 0.005) at brace prescription, 6 months after brace initiation (41 versus 36, p = 0.006), 1 year after brace initiation (40 versus 35, p = 0.04), and at their latest follow-up (39 versus 36, p = 0.03). Twenty-two of the 80 TLSO patients were treated with a RC. There was no difference in PROMIS scores between the TLSO and RC groups. There was a difference between compliance rates for PROV, TLSO, and RC patients (83.5% versus 75% versus 55% respectively, p = 0.006). Four patients in the cohort went on to surgery. All four were in the TLSO group and two were noncompliant with bracing. Patients who failed bracing had worse PROMIS anxiety scores than those who were still in their brace at latest follow-up (49.5 versus 38.2, p = 0.02).

Conclusions: Patients treated with nighttime only bracing have better compliance rates, but similar PROMIS scores compared to those treated with TLSO braces. Patients who are noncompliant with brace wear have worse PROMIS anxiety scores at all time points during bracing, including brace prescription. RC braces do not seem to offer any benefit over traditional TLSO braces in terms of PROMIS scores or brace compliance.

Significance: IS patients with abnormal PROMIS anxiety scores are more likely to be non-compliant with bracing. Identification of patients with anxiety prior to the start of bracing may allow for the opportunity to intervene to increase compliance and may also serve as a prognostic indicator for the success of bracing.

OP-28

Can surgery be proposed to adolescent idiopathic scoliosis patients with structural lumbar curves associated with non-reducible iliolumbar angle?

Laurentiu-Cosmin Focsa, Louise Ponchelet, Mikael Finoco, Anne-Laure Simon, Brice Ilharreborde

Pediatric Orthopedic Department, CHU Robert Debré, Paris, France

LOE-Therapeutic-Level III

Purpose: The iliolumbar angle (ILA, measured between L4 superior endplate and bi-iliac crest line) is an important parameter in Lenke 5 and 6 curves. Assessing its flexibility preoperatively is key to define the surgical strategy and determine the distal level of fusion (LIV). Ending on L4 is always preferable for motion preservation, but an imperfect correction can also lead to distal disk degeneration or coronal imbalance. Reduction rates have recently improved in adolescent idiopathic scoliosis (AIS), due to a greater flexibility than adults and modern instrumentation. The objective of this study was therefore to assess the postoperative outcomes of AIS patients with structural lumbar curves, associated with non-reducible ILA.

Methods: All consecutive AIS patients with Lenke 5 or 6 curves, treated by a posterior fusion ending on L4 between January 2017 and January 2022, were included. A minimum follow-up of 18 months was required. Non-reducible ILA (NR group) was defined as >10° on standing radiographs AND a reducibility <50% on bending films. A control group of reducible ILA (R group) was also analyzed. After independent radiological analysis, postoperative results were classified as follows: excellent if postoperative ILA was <5°, acceptable between 5° and 10° with maintained coronal balance (T1-CSVL < 2 cm), and poor if >10° or if coronal imbalance >2 cm. Scoliosis Research Society (SRS) scores at follow-up were also compared.

Results: A total of 122 patients were enrolled, with 36 patients (30%) included in the NR group. Preoperative ILA was significantly greater in the NR group (20° ± 4° versus 15° ± 6°, p < 0.001). Mean lumbar Cobb angles were significantly reduced postoperatively in both groups, with no significant difference between NR and R groups (p = 0.2). ILA was significantly reduced in both groups after surgery (from 20° ± 4° to 5.7° ± 3° in NR group, p < 0.05, and from 15° ± 6° to 5.1° ± 3° in R group, p < 0.05). No significant difference was found between groups regarding postoperative ILA (p = 0.2). In the NR group, excellent, acceptable, and poor outcomes were achieved in, respectively, 52%, 32%, and 16% of the cases, without significant impact on SRS scores. R group had fewer poor outcomes at follow-up (5%), but the difference did not reach significance. No correlation was found between ILA correction and the demographic or preoperative radiological measures.

Conclusions: Surgery is efficient to restore L4 frontal tilt in AIS patients with main lumbar curves, and a fusion to L4 can still be proposed even if ILA appears non-reducible on preoperative radiographs.

Significance: Level of evidence—III—retrospective cohort study.

OP-29

Utility of routine postoperative laboratory testing after posterior spinal fusion for adolescent idiopathic scoliosis

David Liu, Alexander Farid, Gabriel S. Linden, Danielle Cook, Craig Munro Birch, Michael T. Hresko, Daniel Hedequist, Grant Douglas Hogue

Boston Children’s Hospital, Boston, MA, USA

LOE-Diagnostic-Level II

Purpose: Perioperative blood loss in surgical treatment of adolescent idiopathic scoliosis (AIS) is a major risk. However, with advancements to blood management strategies (intraoperative cell salvage; tranexamic acid), risk of perioperative transfusion has diminished. Despite low rates of symptomatic acute anemia, routine laboratory testing on post-operative day 1 (POD1) and beyond are still commonplace.

Methods: We performed a retrospective cohort study of consecutive patients aged 11–19 with AIS who underwent posterior spinal fusion at a single institution. Univariable logistic regression was utilized to determine whether factors were associated with hematocrit ≤22% on POD1 or a postoperative transfusion. Firth’s penalized logistic regression was used for any separation in the data. Youden’s index was utilized to determine the optimal point on the receiver-operating characteristic (ROC) curve that maximizes both sensitivity and specificity.

Results: Among 527 patients included in this study, only eight had POD1 hematocrit ≤22%; none underwent transfusion. These patients had lower last intraoperative hematocrit levels compared to patients with POD1 hematocrit >22% (24.1% versus 31.5%, p < 0.001), and there was no difference in preoperative hematocrit levels in this group (38.2% versus 39.8%, p = 0.11). Four patients underwent postoperative transfusion. Both preoperative hematocrit levels (34.0% versus 39.9%, p = 0.001) and last intraoperative hematocrit levels (25.1% versus 31.4%, p = 0.002) were lower compared to patients who did not undergo transfusion (Table 1). Intraoperative hematocrit <26.2%, operative time of more than 35.8 minutes per level fused, or cell salvage <241 cc were significant risk factors for postoperative transfusion (relative risk of 105.6; 28.6; and 9.8, respectively) (Table 2). No other risk factors were associated with postoperative transfusion.

Conclusions: Postoperative transfusion after posterior spinal fusion for pediatric AIS is exceedingly rare. POD1 labs should be considered when last intraoperative hematocrit <26%, operative time per level fused >35 minutes, or cell salvage amount >241 cc. Otherwise, unless symptomatic, patients do not benefit from additional laboratory screening on POD1 and beyond.

Significance: Our results suggest that routine postoperative laboratory testing is unnecessary in patients undergoing surgery for AIS, particularly in the setting of advancements like TXA and cell salvage that have effectively limited the risk of blood loss during these procedures. Given the potential negative psychological effects of repeated blood draws on children, in addition to the risks typically associated with venipuncture, reducing the number of postoperative tests can improve the safety and the overall healthcare experience for both the child and their family.

EPOS/POSNA Abstract Book (19)

OP-30

A comparison of opioid-sparing versus opioid-containing postoperative pain management for idiopathic scoliosis

Michael Schallmo, Kayla Hietpas, Michael Paloski

Carolinas Medical Center/OrthoCarolina, Charlotte, NC, USA

LOE-Therapeutic-Level III

Purpose: Several standardized pain management protocols have been reported following instrumented posterior spinal fusion (PSF) for idiopathic scoliosis, aimed at hastening recovery while lowering opioid consumption. However, entirely opioid-free (OF) protocols have yet to be thoroughly evaluated in the pediatric population. The purpose of this study was to compare an OF pain management pathway with a traditional opioid-containing (OC) pathway in pediatric idiopathic scoliosis patients.

Methods: A database of patients who underwent instrumented PSF by a fellowship-trained pediatric orthopedic surgeon was reviewed retrospectively. Patients 10–20 years of age at the time of surgery who had a diagnosis of idiopathic scoliosis and underwent primary instrumented PSF were included. Patients were assigned to one of two groups, based on date of surgery: OF pathway (surgery between June 2019 and July 2020) or OC pathway (surgery between June 2018 and June 2019). Total morphine milligram equivalents (MME) were recorded, beginning once patients reached the inpatient unit postoperatively.

Results: A total of 93 patients (OF = 37, OC = 56) were included. Groups were similar with respect to age and body mass index (Table 1). Patients in the OF group had significantly more levels fused compared with patients in the OC group (11 versus 9.5, respectively; p = 0.0363), though both groups had a similar median length of stay (LOS; 2 days, p = 0.9613). For patients in the OF group, 19/37 (51.4%) required “rescue” doses of opioid medications during admission; 11/37 (29.7%) were prescribed opioids at discharge, compared with 55/56 (98.2%) in the OC group (p < 0.0001).

Conclusions: An OF pathway following instrumented PSF for idiopathic scoliosis results in equivalent LOS and fewer opioids prescribed at discharge compared with an OC pathway.

Significance: To our knowledge, this is the first study to show that OF pain management is possible in this population.

EPOS/POSNA Abstract Book (20)

OP-31

An accelerated postoperative protocol for discharging posterior spinal fusions home in less than 2 days: comparison of two matched cohorts

Chase Bauer, Jeffrey Kessler

Kaiser Permanente, Los Angeles, CA, USA

LOE-Therapeutic-Level III

Purpose: Decadron has recently been shown to help significantly with pain control and decreased length of stay (LOS) in children with scoliosis undergoing posterior spinal instrumentation and fusion (PSIF). We have recently introduced a protocol utilizing postop decadron in addition to accelerated early physical therapy for both our idiopathic (IS) and neuromuscular (NM) scoliosis patients undergoing PSIF. The goal of the present study was to compare LOS in our most recent consecutive cohort of patients (WD) versus a previous patient cohort which did not have accelerated PT or decadron (ND). Secondary outcomes compared included morphine milligram equivalents (MME) and MME/kg in the first 24 h postop, pain score, and infection rate.

Methods: A retrospective chart review of consecutive IS and NM patients with PSIF was performed. Patient demographics along with all intraoperative data and postoperative pain scores and opioid/PCA usage was recorded. Univariate (UV) and multivariable logistic regression analysis (MVLRA) was done to compare the cohorts with 95% confidence intervals (CIs).

Results: Forty consecutive patients in the WD cohort were compared to a prior ND cohort composed of 68 consecutive patients. Cohorts were matched in all patient demographics, body mass index (BMI), levels fused, blood loss, and curve magnitude. Both UV and MVLRA showed no significant difference in maximum or median pain score or MME/kg. The WD cohort averaged 1.06 less days LOS (1.73 versus 2.79, p = 0.0007), and MVLRA also demonstrated that the WD protocol led to a 1 day decreased odds ratio (OR) of LOS (CI = −1.57 to −0.44, p = 0.006). MVLRA also showed 96% decreased OR of using a PCA (OR = 0.04, CI = 0.01–0.13, p < 0.0001), with only 37.5% of patients in the WD group requiring a PCA versus 89.7% in the ND group. The infection rate was 0% and 5%, respectively, in the ND and WD group; both UV and MVLRA showed no significant difference in infection rate between these groups.

Conclusions: This accelerated postoperative spine protocol led to a 38% decrease in LOS, with a 96% decreased OR of needing a PCA despite the MME/kg use not being significantly different. Pain scores were not significantly decreased in the WD group, likely due to these patients being more rapidly mobilized and thus more active during the first 24 h postop.

Significance: This study demonstrates that, for the first time, hospital discharge on postoperative day 1 may be possible, with 70% of all NM and IS patients being discharged on postoperative day 1 over the past 10 months.

OP-32

Can surgery improve painful adolescent idiopathic scoliosis patients?

Arthur Poiri, Louise Ponchelet, Anne-Laure Simon, Florence Julien-Marsollier, Mikael Finoco, Brice Ilharreborde

Pediatric Orthopedic Department, Robert Debré University Hospital, Paris, France

LOE-Therapeutic-Level III

Purpose: Posterior fusion is the gold standard surgical procedure to correct progressive adolescent idiopathic scoliosis (AIS). Optimizing perioperative management is key to improve postoperative outcomes and to avoid the non-negligible risk of chronic pain reported after surgery. Preoperative back pain has been associated with poorer functional scores in adults, but the influence of this parameter remains unclear in the AIS population. The aim of this study was therefore to evaluate the incidence of pain in AIS surgical candidates and report the postoperative outcomes of patients with significant preoperative pain.

Methods: All consecutive AIS patients who underwent posterior fusion between 2015 and 2022 were included, with a minimum 1-year follow-up. Demographic data, VAS, and Scoliosis Research Society (SRS)-22 scores were analyzed. Back pain group (BP) was defined as a preoperative VAS >3, while the back pain free group (BPF) had a VAS ≤3. Radiological measurements were performed before and after surgery by an independent observer. Scores and radiological measures were compared between groups before and after surgery.

Results: A total of 319 patients were enrolled, with 120 patients included in the BP group (pain incidence 37.6%). Mean follow-up was 31 ± 18 months. No difference was found between groups regarding mean preoperative main Cobb and correction rates (p = 0.39 and p = 0.25, respectively). Preoperative VAS averaged 5.7 ± 1.4 in the BP group and 0.38 ± 0.9 in BPF (p ≤ 0.01). No correlation was found between pain and any demographic or radiological parameter. After surgery, VAS was significantly reduced in the BP group (p ≤ 0.01), and 68% of the patients reported non-significant pain at latest follow-up. Mean SRS total scores significantly improved in BP patients (from 3.48 ± 0.41 to 3.89 ± 0.65, p ≤ 0.01). SRS satisfaction domains were significantly greater in patients initially painful (from 3.11 ± 0.66 to 4.33 ± 0.78, p ≤ 0.01). BP and BPF patients had no significant difference in postoperative VAS, SRS total, and all domains’ scores after surgery.

Conclusions: Back pain is a frequent and underestimated symptom in AIS surgical candidates, not correlated with deformity magnitude. It can be significantly improved after surgery, so its presence should not delay or contraindicate surgery. A comprehensive approach of the associated psychosocial factors remains necessary in painful patients, but outcomes and satisfaction are not negatively impacted.

Significance: Level of evidence—III—retrospective cohort study.

OP-33

The postoperative decline in health-related quality of life for adolescents with idiopathic scoliosis undergoing spinal fusion

Adam A. Jamnik, Emily E. Lachmann, Anne-Marie D. Datcu, David C. Thornberg, Chan-Hee Jo, Karl E. Rathjen, Megan Johnson, Brandon A. Ramo

Scottish Rite for Children, Dallas, TX, USA

LOE-Not Applicable-Not Applicable

Purpose: The daily lives of adolescents have changed dramatically since the initial creation of the Scoliosis Research Society (SRS) questionnaire, with more time spent on social media and engaging in sedentary behaviors. We have previously demonstrated a decline in SRS scores over the last 2 decades for adolescent idiopathic scoliosis (AIS) patients prior to surgery. Meanwhile, one would reasonably conclude that improvement of techniques in surgical scoliosis management should improve postop outcomes over this same time. The purpose of this study is to evaluate how 2-year postoperative SRS scores for surgical AIS patients have changed over 2 decades.

Methods: Retrospective review of consecutively enrolled AIS patients undergoing definitive fusion (DF) at a single institution between 2002 and 2022. Patients were included if they completed an SRS questionnaire between 21 and 49 months postoperatively, classified as 2-year follow-up. A multivariate linear regression was performed with the outcome as the 2-year SRS domain and total scores and the variable of interest as the year the survey was completed. Variables included to minimize confounding were the corresponding preoperative SRS domain score, gender, race, body mass index (BMI), and age at surgery.

Results: A total of 788 patients met the inclusion criteria. Patients were 83.8% female, had a mean age at DF of 14.3 ± 2.0 years, and a mean preoperative major Cobb angle of 61.7° ± 11.1°. Of the potential confounding variables included, preoperative SRS score, body mass index (BMI), gender, and race contributed significantly to the model. Later (more recent) SRS completion years were associated with worse health-related quality of life (HRQoL) in the Mental Health domain (N = 782, coefficient = −0.009, p = 0.0432) and the Activity domain (N = 782, coefficient = −0.007, p = 0.0340) (Figure 1). The relationship between SRS completion year and SRS scores was not significant for Pain (N = 785, coefficient = −0.003, p = 0.4680), Appearance (N = 784, coefficient = 0.005, p = 0.2645), or Satisfaction (N = 689, coefficient = −0.003, p = 0.4939).

Conclusions: Patients with AIS who underwent DF in more recent years are reporting worse postoperative HRQoL for both Activity and Mental Health. Extrinsic causes likely play a role. Whereas we previously showed declining preoperative SRS Pain and Appearance scores over time, the effects of surgery may mitigate this, as the 2-year postoperative scores have not worsened over time.

Significance: Healthcare providers should be cognizant of these downward trends and should consider using adjunct treatments to support postoperative patients with AIS, such as physical and psychological therapy. Similarly, when comparing postoperative patient-reported outcomes of scoliosis patients from different time periods, clinicians and researchers should be cautious of the confounding role that external, societal factors may play in adolescents’ lives.

EPOS/POSNA Abstract Book (21)

OP-34

The CoCo (Core Outcome ClubfOot) study: recurrence, with poorer clinical and quality of life outcomes, affects 37% of patients—an international multicenter observational study

Yael Gelfer, Sean Cavanagh, Anna Bridgens, Maryse Bouchard, Elizabeth Ashby, Deborah Eastwood

St George’s Hospital, London, UK

LOE-Therapeutic-Level II

Purpose: The Ponseti method is the global gold standard treatment for clubfoot. However, recurrence rates, treatment of recurrence, and the frequency of further interventions vary widely. All increase with duration of follow-up. There is a lack of high-quality research investigating clinical and quality of life (QoL) outcomes in children with clubfoot and how they correlate with deformity recurrence. The aim of this study was to assess clinical and QoL outcomes in children with clubfoot treated by the Ponseti method using a standardized Core Outcome Set (COS) and compare these in children with and without relapse and in those requiring further treatment.

Methods: Eleven international clubfoot centers participated in this institutional review board (IRB)–approved observational study. Data were collected from consecutive clinic patients from 1 June 2022 to 30 June 2023, with a minimum 5-year follow-up. A standardized proforma was used for data collection including demographics, information regarding primary presentation and treatment, and details of subsequent relapse and further treatment. The clubfoot COS incorporating 31 parameters of clinical and QoL outcomes was used. Data were pooled across hospital centers for analysis. A regression model was used to assess relationships between baseline variables and outcome measures and between the clinical and QoL outcomes.

Results: A total of 293 patients (432 feet), median age 89 months (range, 72–113), were included. The relapse rate was 37%, with more than one relapse in 13%. Treatment for relapse considered a standard part of the Ponseti journey (recasting, repeat tenotomy, and tibialis anterior tendon transfer (TATT)) was documented in 35% of cases. Soft tissue release and osteotomies were documented in 5.4% and 2.4% of cases, respectively. Predictors of relapse included higher age at follow-up, higher initial Pirani score, and poor evertor muscle activity. Relapse and further treatment were associated with poorer outcomes. The total score and the physical component of the Oxford Foot and Ankle Score were higher and the clinical examination better in children who did not experience relapse. Thirty-seven percent of the children were unable to squat. This was related to reduced ankle dorsiflexion.

Conclusions: Patients who were treated according to the Ponseti method experienced 37% relapse. Patients with no relapse had superior core outcomes.

Significance: This is the first multi-center study using a standardized COS following Ponseti clubfoot treatment. It distinguishes patients with and without relapse in terms of clinical outcomes and QoL. This tool can serve to compare treatment methods and outcomes, can facilitate information sharing, and sets expectations with families.

OP-35

Comparison of clinical outcomes, parental anxiety, and surgeon satisfaction during outpatient clinic versus operating room setting for Achilles tenotomy during Ponseti method of clubfoot correction—a randomized controlled trial

Karthick Sengoda Gounder Rangasamy, Premkumar Rajakumar, Nirmal Raj Gopinathan

Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India

LOE-Prognostic-Level II

Purpose: Achilles tenotomy (AT) during idiopathic clubfoot correction can be performed either in an outpatient clinic (OPC) or operating room (OR) setting. However, there is no clear consensus regarding where to perform AT to produce better outcomes without major complications. To the best of our knowledge, no randomized controlled trial (RCT) was conducted to compare these two settings. Research question: Is AT done in OR under general anesthesia (GA) better than in OPC under local anesthesia (LA)?

Methods: Through block randomization, 40 idiopathic clubfoot cases were allotted equally to the OPC and OR groups. After satisfactory correction of midfoot cavus, forefoot adduction, and hindfoot varus using Ponseti casting, percutaneous scalpel AT was performed for correcting ankle equinus either in OPC or OR. Parental anxiety through the STAI questionnaire, self-designed surgeon satisfaction questionnaire, and ankle dorsiflexion at the final follow-up were assessed.

Results: The mean age in the OPC and OR groups were 4.18 and 5.03 months, respectively. The mean number of casts was comparable between groups. The mean duration of the procedure was 19.80 and 53.50 minutes in the OPC and OR groups, respectively (p < 0.001). The mean infant–mother separation time was 59.75 minutes in the OR group. Intra-op bleeding was seen in three (15%) patients in the OPC group and one (5%) patient in the OR group; statistically insignificant (p = 0.605) between groups. Parental anxiety during the initial presentation at the clinic and pre- and post-operative periods were comparable in both groups. The mean total surgeon satisfaction score favors OR (25.10) as their preferred setting in comparison to OPC (23.05) (p = 0.009). The mean ankle dorsiflexion on 1-year follow-up in the OPC and OR groups was 17.80° and 17.95°, respectively.

Conclusions: AT done in OPC under LA is a safe, cost-effective procedure with less infant–mother separation time and decreased overall procedural duration. Also, this setting has comparable clinical outcomes and similar parental anxiety during the pre- and post-procedural period to that done under GA in the OR.

Significance: AT during the Ponseti correction method in idiopathic clubfoot can be done safely, cost-effectively, and with less infant–mother separation time in OPCs. OR setting shows no significant additional advantage for doing AT in idiopathic clubfoot except for surgeon satisfaction.

OP-36

Effect of the abduction bracing on the contralateral foot in patients with unilateral clubfoot deformity: a longitudinal study

Kelly Jeans, Victoria Blackwood, Anthony Riccio

Scottish Rite for Children, Dallas, TX, USA

LOE-Therapeutic-Level II

Purpose: Although numerous studies have assessed function of idiopathic clubfeet (CF) treated by the Ponseti method, few studies have assessed alterations in the normal foot of patients with unilateral CF imparted by Ponseti bracing. The purpose of this study was to identify pedobarographic differences in the unaffected foot of unilateral CF patients treated with the Ponseti abduction brace, and if those differences persist over time.

Methods: Patients with unilateral idiopathic clubfoot treated during infancy by either the Ponseti method (CF group) or the French Physical Therapy Method (PT group) were prospectively followed until 16 years of age. Those in the CF group used abduction braces 23 h a day for a minimum of 3 months followed by nighttime brace wear until a minimum of 2 years of age. Those in the PT group used a custom unilateral orthosis on only the affected foot during the maintenance phase of treatment. Pedobarographic assessment of the unaffected foot was collected longitudinally at 2, 5, 10, and 16 years of age. Non-parametric Mann–Whitney U tests were used to compare plantar contact area (CA%), mean force (MF%), and contact time (CT%) between groups.

Results: Forty-four patients (19 in the CF group and 25 in the PT group) underwent pedobarographic assessment at all time intervals. The CF group demonstrated significantly higher MF% and CT% as a percentage of the rollover process in the medial and lateral midfoot at 2 years of age. These differences, however, resolved by age 5, with no difference noted in plantar pressures between groups at age 16 (Table 1).

Conclusions: Abduction bracing of normal feet in patients with unilateral CF deformity results in measurable increases in midfoot plantar pressure and contact time during the brace phase of treatment indicating that bracing does impart an increased pes planus posture of the unaffected foot. These changes, however, appear to resolve following cessation of brace use.

Significance: Although abduction bracing of the unaffected foot in children with unilateral CF deformity following Ponseti casting does result in increased midfoot pressures, these changes are transient and are expected to resolve after brace discontinuation. This information should be reassuring to parents of unilateral CF patients concerned about the effect of abduction bracing on the normal foot.

EPOS/POSNA Abstract Book (22)

OP-37

Clubfoot relapse rates in idiopathic clubfoot using the Ponseti method: 65 years of data from a single institution

Jose A. Morcuende, Arianna Dalamaggas, Malynda Wynn

University of Iowa, Iowa City, IA, USA

LOE-Therapeutic-Level IV

Purpose: Clubfoot is the most common musculoskeletal birth defect in the United States, and it is widely agreed upon that conservative management using the Ponseti method of casting is the most effective treatment, consisting of correction by manipulation and casting, Achilles tenotomy, and prevention of relapse by bracing. However, relapses can still occur and may result in significant long-term morbidity for patients if not managed appropriately. No current literature discusses long-term rate of relapses with most studies limited by smaller cohorts, short follow-up, and deviations from the original method making clinical conclusions difficult. The purpose of this study is to determine relapse rate of patients with congenital idiopathic clubfoot spanning 65 years of practice.

Methods: This is a retrospective cohort study of patients treated for clubfoot at a tertiary center between 1948 and 2013. A Kaplan–Meier survivorship curve for relapse rate was used to evaluate relapse rate in patients with and without prior treatment, as well as for those adherent and non-adherents with brace treatment. Multivariate Cox models were used to assess which factors were significantly associated with relapse rate.

Results: Of the 1580 feet in the population, we found that non-compliance with bracing during the maintenance phase is the largest risk factor for relapse. The relapse rate without prior treatment was 8.9% and with prior treatment, 18.9%. Non-adherence without prior treatment increased the relapse rate to 93.6%, and with prior treatment, 95.7%. Patient age, gender, family history, unilateral versus bilateral clubfoot, prior treatment, and indication for tenotomy were not significantly associated with relapse rate. However, a higher number of casts required for correction (>7) and brace non-adherence were significant associated with relapse rate (p < 0.0001).

Conclusions: This study supports that proper technique and brace adherence lead to lower rates of relapse and further demonstrates that after the age of 5 years, relapse occurs as low as 5%. Other studies provide highly variable relapse rates with shorter follow-up. This study provides information on risk for relapses, with the greatest risk factor being number of casts needed for correction and brace adherence over 65 years of practice.

Significance: Many factors are described in the current literature to be associated with clubfoot relapse; however, this study with 65 years of data shows that number of casts for correction and brace adherence are most significant factors for preventing relapse, with decreasing likelihood after the age of 5.

OP-38

Comparative analysis of three anterior tibialis tendon transfer techniques in idiopathic clubfoot

Gregory Firth, Javier Masquijo, Alexandre Arkader, Victoria Allende Nores, Manoj Ramachandran

Royal London Hospital, London, UK

LOE-Therapeutic-Level III

Purpose: Recurrence in clubfoot after the Ponseti technique is a well-recognized phenomenon. The use of the anterior tibial tendon transfer (ATTT) is a well-documented technique for addressing dynamic supination following treatment. Despite its widespread use, there is a lack of comparative studies evaluating different fixation techniques for ATTT. Consequently, we conducted a multicenter study to assess and compare the outcomes of three techniques.

Methods: Three centers from three different continents collaborated in this comparative analysis. Children with dynamic supination after initial Ponseti treatment who underwent ATTT between 2008 and 2023 were included. Exclusion criteria were neuromuscular disease, associated syndromes, partial tendon transfer, and follow-up <6 months. A pull-through technique with suture over a button (Group A) was used in 52 patients (72 feet), a pull-through technique using an interference screw fixation (Group B) was used in 23 patients (26 feet), and a novel suture anchor technique (Group C) was used in 55 patients (65 feet). A retrospective review included demographics, surgical procedures, and outcomes (active contraction of the ATTT, recurrence, and postoperative complications). The comparison between the three groups was made with analysis of variance (ANOVA) and Kruskal–Wallis tests. p-values of <0.05 were considered statistically significant.

Results: A total of 130 children (163 feet), were included. There were no statistically significant differences in age, sex, side, and isolated ATTT versus ATTT + additional surgery (soft tissue or bony) between groups. At final follow-up (mean, 42.0 months), 28 patients (38 feet) experienced some form of relapse of any aspect of the clubfoot: Group A, 27.8% (20/72 feet), Group B, 27.6% (8/29 feet) and Group C, 15.4% (10/65 feet), p = 0.41. There were five postoperative complications directly related to the ATTT, comprising four cases in Group A (5.6%) and one in Group B (1.5%), p = 0.88. Of these complications, only one case from Group A included pull out of the transferred tendon. There were no cases of overcorrection.

Conclusions: All three fixation techniques effectively secure the tibialis anterior tendon transfer in the pediatric population. The suture anchor technique may present a slightly lower recurrence and complication rate. Future large-scale studies are needed to validate these findings and provide further insights into optimal ATTT techniques.

Significance: The suture anchor and screw techniques have demonstrated their utility in addressing recurrent dynamic supination. In situations where the tendon length may be insufficient or the bone dimensions are inadequate for a pull-through approach, the suture anchor technique stands as a safe and effective alternative.

OP-39

Rebound of the radiological effect of anterior distal tibia epiphysiodesis in relapsed Ponseti-treated clubfoot patients after implant removal

Arnold T. Besselaar, Maria Christine Van Der Steen, Isabelle Van Tilburg

Máxima Medisch Centrum, Veldhoven, The Netherlands

LOE-Therapeutic-Level IV

Purpose: Despite good initial results, 1.9% and 67% of the clubfoot patients treated with the Ponseti method might experience a relapse. In case repeated Ponseti treatment yields insufficient results, additional treatment might be necessary. Anterior distal tibial hemi-epiphysiodesis (ADTE) with eight plates has been proposed as treatment for recurrent equinus deformity. So far clinical results were inconsistent and mainly focused on correction during treatment. In the current project, we also evaluate outcome at least 1 year after 8-plate removal as a resumption on the project earlier presented at EPOS.

Methods: We included idiopathic clubfoot patients aged between 4 and 12 years, who are initially treated with the Ponseti method and treated with hemi-epiphysiodesis between 2015 and 2022. Patients were assessed preoperatively at indication for 8-plate removal and if available at least 1 year after 8-plate removal. A senior orthopedic surgeon specialized in clubfoot treatment determined passive ankle dorsiflexion. Furthermore, on standardized lateral radiographs, the anterior distal tibial angle (ADTA) was measured.

Results: The median treatment duration of 45 feet (31 patients, 42% female) was 22.7 (range: 9.4–37.0) months. Both ankle dorsiflexion and ADTA improved during hemi-epiphysiodesis. From 23 of these feet also a radiological assessment at least 1-year follow-up after removal of hardware was available. The ADTA showed significant increase (p < 0.001) after 8-plate removal, by modeling back to preoperative values. In the subgroup with 1-year follow-up available, no change in dorsiflexion was found. One patient undergoing bilateral hemi-epiphysiodesis experienced a wound infection and screw migration.

Conclusions: ADTE with eight plates is an effective method to achieve slope correction. However, after 8-plate removal, regression of ADTA occurs. Physicians, parents, and patients should be informed about this mechanism which might result in different timing of the treatment and possibly the need for renewed hemi-epiphysiodesis. To what extent the degree of relapse is related to age and therefore potential for residual growth is still unclear. More clarity on this would provide insight into the timing of epiphysiodesis as relapse treatment for clubfeet patients with a recurrent equinus deformity.

Significance: As far as we are aware, this is the first study showing a rebound effect of the ADTA after implant removal of an anterior distal tibial hemi-epiphysiodesis as a treatment for recurrent equinus deformity in Ponseti-treated clubfoot patients.

OP-40

Is there a benefit to rigid fixation in calcaneal lengthening osteotomy in painful pediatric idiopathic flatfoot deformity? Comparing results of Kirschner wire versus plate fixation

Abhishek Tippabhatla, Beltran Torres-Izquierdo, Daniel Pereira, Zachary Meyer, Pooya Hosseinzadeh

Washington University School of Medicine, Saint Louis, MO, USA

LOE-Therapeutic-Level III

Purpose: Flexible flatfoot (FF) is a common pediatric condition that is mostly asymptomatic, and surgical intervention is only considered when painful FF is refractory to conservative treatment. Calcaneal lengthening osteotomy (CLO) is one of the most used procedures to address painful FF. Traditionally, Kirschner wires were used for fixation, but there has been a recent increase in the use of plates. We compared the clinical and radiographic outcomes of these two fixation methods.

Methods: This single-center retrospective study included children aged 8–18 years with symptomatic FF that received CLO using K-wire or plate fixation. Primary outcomes include weight-bearing radiographic measurements and complications following surgery. Secondary outcomes included patient-reported outcomes. Statistical significance was held at 0.05.

Results: Among 102 feet (65 patients), 42 feet (41.2%) underwent K-wire and 60 feet (58.8%) underwent plate fixation. No differences in casting duration (p = 0.525) and time to radiographic healing (p = 0.17) were noted. Total complications were higher in the plate cohort (12 versus 2, p = 0.04) due to a higher rate of reoperations (16.7%) for hardware-related pain (10 versus 0; odds ratio (OR) = 17.74, 95% confidence interval (CI) = 1.01–310.54, p < 0.05), and infection rates were similar. Both interventions significantly improved (p ≤ 0.001) anteroposterior (AP) talo-first metatarsal and calcaneal pitch angles. Irrespective of intervention, CLO significantly improved pain at 6 months and mobility scores at 12 months. Neither modality demonstrated superior pain or mobility scores at final follow-up.

Conclusions: Both K-wire and plate fixations lead to similar radiographic and functional outcomes after CLO in painful, pediatric flatfeet. Compared to K-wire fixation, plates cause a 17.7-fold increased risk of reoperations for painful hardware, with 16.7% of plated cases requiring reoperation.

Significance: Noting this, along with the higher costs associated with using plates, our study advocates for K-wire fixation for children undergoing CLO.

EPOS/POSNA Abstract Book (23)

OP-41

Nonunion rate of Evans osteotomy without fixation in pediatric flatfoot

Smitha Mathew, Brian Gallagher, Megan Miles, Gregory Paul Guyton

MedStar Union Memorial Hospital, Baltimore, MD, USA

LOE-Therapeutic-Level IV

Purpose: The Evans osteotomy is a lateral column lengthening procedure of the calcaneus that is commonly used to correct flatfoot deformities. Currently, there is no consensus on whether fixation is needed when performing this osteotomy. Furthermore, the use of large sized grafts for the Evans osteotomy has been associated with degeneration of the calcaneocuboid joint. The aim of this study was to determine the union rate of an unfixed Evans osteotomy with the use of a relatively small allograft wedge performed in pediatric patients undergoing flexible flatfoot reconstruction.

Methods: We retrospectively reviewed 39 pediatric patients with idiopathic symptomatic flatfoot deformity who underwent 46 unfixed Evans osteotomies with allogenic bone graft for flatfoot reconstruction between March 2013 and September 2017, with a mean follow-up of 49 (range, 9.9–243.9) weeks. Hospital record, preoperative and follow-up radiographs, and complications were reviewed.

Results: Of the 46 feet, 42 (91.3%) underwent a double calcaneal osteotomy with an associated medial displacement calcaneal osteotomy (MDCO). Mean graft wedge size was 7.2 mm (SD = 1.6 mm). The mean time to union was 10.3 (range, 6.7–13.9; SD = 1.5) weeks (Table 1). There were no nonunions. One patient (one foot) had persistent sinus tarsi pain requiring arthroscopic debridement of fibrosis and graft prominence. Significant improvement was observed in all radiographic parameters at final follow-up, including calcaneal pitch, talonavicular uncoverage, anteroposterior and lateral talo-first metatarsal angle, and lateral column length (p < 0.05) (Table 2). Postoperative calcaneocuboid subluxation occurred in 70% of feet, with no correlation with wedge size (r = 0.01, p = 0.53). Mean change in calcaneocuboid subluxation at final follow-up was 1.07 mm (SD = 2.18), with postoperative calcaneocuboid subluxation diminishing over time (Table 3). There was also no correlation between wedge size and change in lateral column length (r = 0.01, p = 0.45).

Conclusions: An unfixed Evans osteotomy for symptomatic flatfoot deformity resulted in a significant improvement in the radiographic alignment of the foot with no nonunion at final follow-up. Although calcaneocuboid subluxation was found in 70% of feet, it was small in magnitude and diminished with time. Mean graft size in our cohort was smaller than that reported by other studies.

Significance: No fixation of the Evans osteotomy was required to achieve a 100% union rate with minimal calcaneocuboid subluxation in this pediatric population. Performing adjunctive procedures may allow for less than 10 mm of lengthening with this procedure.

EPOS/POSNA Abstract Book (24)

OP-42

Improving detection of underlying neurologic etiology for pediatric cavovarus foot deformity: we can do better

Mike O’Sullivan, Michelle Christie, Rusty Lynn Hartman, Jacob Zide, Anthony Riccio

Scottish Rite for Children, Dallas, TX, USA

LOE-Diagnostic-Level IV

Purpose: While evaluation of an underlying neurologic disorder in children with cavovarus foot deformity (CVD) is of great importance, no standardized method of neurologic assessment exists. Moreover, the yield of commonly used diagnostic measures remains unstudied. This study aims to compare the diagnostic yield of traditional methods of neurologic assessment for patients with CVD of unknown etiology to a more advanced diagnostic algorithm (ADA).

Methods: An institutional review board (IRB)-approved retrospective review of patients presenting to a single pediatric tertiary care center for bilateral or unilateral CVD was performed over a 19-year period. Patients with a known etiology for their deformity or pre-existing neurologic or syndromic diagnoses were excluded. Neurologic evaluation of all remaining patients was conducted by a pediatric neurologist using one of two diagnostic algorithms. The traditional diagnostic algorithm (TDA) consisted of clinical examination, magnetic resonance imaging (MRI) of the brain and spinal cord, and/or electromyography (EMG)/nerve conduction velocity (NCV). The ADA included all components of the TDA in addition to genetic testing, and/or muscle/nerve biopsy and/or repeat EMG/NCV testing when initial workup remained negative. These diagnostic algorithms were compared regarding determination of an underlying etiology for CVD.

Results: A total of 108 patients (average age 9.7 years) were included. Ninety-six patients were assessed via the TDA which detected an underlying neurologic diagnosis in 56 (58%) patients. Of these, 15 had central neurologic disease, 35 had peripheral neuropathies, and 6 had combined central and peripheral neuropathology. Of the 40 patients in whom no diagnosis was made using the TDA, 21 were further assessed using the ADA which revealed a diagnosis in 15 (71%) patients, thereby increasing the diagnostic yield to 71/77 patients (92%) when the ADA was incorporated and 71/96 (74%) overall. Moreover, 23 of 41 patients (56%) diagnosed with an unspecified polyneuropathy by TDA received a more specific diagnosis when TDA was combined with ADA. Definitive diagnosis was achieved solely by genetic testing without utilization of the TDA in 12 patients, 75% of whom had variants of Charcot-Marie-Tooth disease.

Conclusions: Neurologic etiology remains undetected in 42% of children with CVD using solely neuroaxis imaging and electrodiagnostic testing. Determination of an underlying neurologic cause for deformity can be increased by over 30% through the incorporation of genetic testing and other components of the ADA.

Significance: When used in lieu of or in addition to traditional diagnostic tools for neuropathology, the addition of genetic testing and, as needed, tissue biopsy or repeat EMG/NCV markedly increases the ability to detect or further specify a neurologic etiology for CVD.

OP-43

Efficacy of Ponseti casting in arthrogryposis

Theresa A. Hennessey, Ferran Romero, Amanda Purcell, Angielyn San Juan, Bruce MacWilliams

Shiners Children’s Salt Lake City, Salt Lake City, UT, USA

LOE-Therapeutic-Level III

Purpose: Clubfeet associated with a diagnosis of arthrogryposis multiplex congenita (AMC) are more difficult to treat than idiopathic classifications. The amount of initial treatment, additional treatment, and relative success of casting protocols, however, are not well known, particularly with moderate to long-term follow-up.

Methods: A total of 624 consecutive patients undergoing Ponseti casting for clubfoot between 2000 and 2022 were retrospectively reviewed and grouped by diagnosis with inclusion criteria being treatment initiated within the first 6 months of age, a diagnosis of arthrogryposis or an exclusionary diagnosis of idiopathic club foot (ICF), and a minimum of 5-year follow-up. Groups were propensity matched on gender, laterality, and age at initial cast. Casting data, recurrence incidence, posterior medial release (PMR) surgery, salvage procedures, and additional surgeries such as repeat TALs and other tenotomies were compared between groups. Differences reported here met statistical significance by Student t-test or Fisher’s exact test unless otherwise indicated.

Results: Twenty-three individuals with AMC and 185 with ICF met the inclusion criteria. All AMC subjects were bilateral. Propensity matching determined a subset of 23 ICF subjects for statistical comparison. No differences in time or casts applied were found in initial casting treatment. Children with AMC were 30% more likely to have at least one recurrence (87% versus 50%, odds ratio = 5.0), recurred at a younger age (1.4 versus 3.0 years), and required more casts for the first recurrence (4.0 versus 2.3). Ten AMC children (43%) went on to PMR surgery compared to one ICF (4%), an odds ratio of 17. Five AMC individuals further went on to a salvage procedure, primarily talectomy. Rates of additional surgeries were not different between groups (61% AMC versus 48% ICF).

Conclusions: Some important differences reflecting the challenges of treating club foot in the arthrogryposis population were determined in this study. Most significantly, children with AMC were 5 times more likely to have recurrence and 17 times more likely to require PMR. Still, more than half of the AMC group were successfully treated without PMR or salvage operations and did not require more frequent additional surgeries to augment casting.

Significance: Understanding the treatment course and outcomes of Ponseti treatment for clubfoot can help inform the expectations of both the provider and the patient and family. We compare these findings in children with arthrogryposis to the more commonly managed idiopathic clubfoot group to add perspective for this population.

OP-44

Is the proximal lateral epiphysiodesis of the first metatarsal effective in the correction of hallux valgus in the pediatric population?

Emanuel Seiça, Teresa Clode Araújo, Afonso Cardoso, Susana Norte, Monika Thüsing, Manuel Cassiano Neves

Hospital CUF Descobertas, Lisbon, Portugal

LOE-Diagnostic-Level III

Purpose: Juvenile hallux valgus (JHV) is a forefoot deformity of the skeletally immature population with an increase in the hallux valgus and intermetatarsal angle, impacting the quality of adult life. Correction of angular deformities by epiphysiodesis was first described by Blount and become popular with “guided growth surgery.” Our objective study was to analyze the effect of guided growth of the first metatarsal in the correction of these parameters at the end of growth.

Methods: We retrospectively reviewed 64 feet with JHV with a severe family history, submitted to proximal lateral epiphysiodesis of the first metatarsal (2012–2022). Radiological measurements were performed on weight-bearing X-rays. Seven parameters were measured. The American-Orthopedic-Foot-and-Ankle-Society-Hallux-Scale (AOFAS) was applied pre/post-operatively. All patients were operated by the same technique (percutaneous drilling/curettage of the lateral quart of the proximal growth plate of the first metatarsal). One-way analysis of variance (ANOVA), Mann–Whitney U test, and chi-square test were used in statistical analysis.

Results: The mean follow-up was 2.6 years. There were no major complications. HVA improved in 48/64 feet (75%). The average HVA change was 4.2° (SD = 4.3°). IMA improved in 50/64 feet (78%). The average IMA change was 1.6° (SD = 1.9°). Both IMA and HVA improved in 47/64 feet (73.4%). Correction to reference values for HVA occurred in 38/64 feet (60%) and for IMA occurred in 37 feet (58%). These patients had a lower pre-operative HVA (20.8° versus 25.3°), IMA (11.0° versus 14.0°), PMAA (2.0° versus 3.1°), and DMAA (3.7° versus 9.1°). The AOFAS improved in 62/64 feet (97%). The average change in AOFAS was 23.6 (SD = 10.09). The average PMAA change was 1.4 valgus (SD = 2.6). There was no considerable effect in DMAA. No evidence of bone growth arrest was documented.

Conclusions: Hemiepiphysiodesis is a valid management option, with an overall good outcome in 60% of patients. However, if we consider the mild/moderate cases, this number rises to 84%, being effective in halting disease progression and improvement in patient’s symptoms and aesthetic concerns.

Significance: Few studies reported on the results of hemiepiphysiodesis in correction of JHV, however with mixed results. This is the first study that tries to identify predictive X-ray parameters for good results.

OP-45

The creation and validation of an ankle bone age atlas and data predicting remaining ankle growth

Andrew Pennock, James David Bomar, Jason Pedowitz, Stephen Carveth

Rady Children’s Hospital, San Diego, CA, USA

LOE-Prognostic-Level IV

Purpose: Premature physeal closure is frequently encountered in the management of pediatric distal tibia physeal fractures. An accurate bone age assessment is invaluable in optimizing decision making with respect to prognosis and treatment. The purpose of the current study was twofold: (1) to create and validate an ankle bone age (BA) atlas spanning the pediatric and adolescent years and (2) to utilize this atlas in conjunction with distal tibia/fibular growth data as measured on serial radiographs to develop a predictive growth model for the lower extremity.

Methods: Radiographs were surveyed to identify distinguishable and reproducible features of the tibia, fibula, hindfoot, and midfoot. In a similar manner to the creation of the Greulich and Pyle atlas, a “standard” for each age/sex was selected to create an ankle BA atlas. A separate cohort of 90 patients was selected to validate the atlas. A sub-cohort of 41 patients with left-hand radiographs within 3 months of ankle imaging was used to compare the two BA approaches. Furthermore, Harris growth lines were evaluated using 304 serial images of the distal tibia to determine remaining growth.

Results: The distal tibia/fibula ossification centers provided the best age assessment for early childhood (male age: 1–6 years; female age: 1–5 years). The ossification/fusion of the calcaneal apophysis provided the best age assessment in the preadolescent stage (male age: 6–14 years; female age: 5–12 years). The closure of the distal tibia/fibula physes best determined skeletal maturity (male age: 14–16; female age: 12–14 years). The ankle atlas had excellent inter- and intra-observer reliability (intraclass correlation coefficient (ICC) = 0.993, p < 0.001 and 0.998, p < 0.001), respectively. We found excellent correlation between the patient’s chronologic age and ankle BA (r = 0.984; p < 0.001). Ankle BA assessment and G&P were correlated (rs = 0.822, p < 0.001). We found that males with a BA of ≥15 years and females with a BA of ≥13 years had ≤2 mm of residual growth of the distal tibia/fibula physes (Table 1).

Conclusions: BA can be determined using ankle films ordered to assess/treat ankle injuries. This tool, along with our growth remaining table, may have important clinical implications when managing ankle trauma patients with premature physeal closure.

Significance: This atlas can be utilized to help guide the surgeon as to the potential need and timing of surgical intervention after skeletal trauma associated with a premature physeal closure.

EPOS/POSNA Abstract Book (25)

OP-46

Hip progression after triradiate cartilage closure in ambulatory cerebral palsy: who needs continued surveillance?

Amelia M. Lindgren, Ali Asma, Kenneth Rogers, Freeman Miller, M. Wade Shrader, Jason Howard

Nemours Children’s Hospital, Delaware, Wilmington, DE, USA

LOE-Prognostic-Level III

Purpose: Hip surveillance in cerebral palsy (CP) is an accepted practice with consensus-based guidelines adopted worldwide. For the skeletally immature, with open triradiate cartilage (TRC), recommendations for radiographic surveillance stemmed from population-based studies. For non-ambulatory CP, progression of hip displacement (HD) after skeletal maturity has recently been reported, with risk factors including a migration percentage (MP) >35% and pelvic obliquity at TRC closure. Less is known, however, for ambulatory CP. The objective was to determine the prevalence and risk factors associated with progressive HD after TRC closure, a proxy for skeletal maturity, for persons with ambulatory CP.

Methods: Retrospective cohort study. Patients with ambulatory CP (Gross Motor Function Classification System (GMFCS) I-III), hypertonic motor type, regular hip surveillance (3+ X-rays after age 10 years, 1 prior to TRC closure, 1+ after age 16 years), and 2-year follow-up post TRC closure were included. The primary outcome was MP. Secondary outcomes included previous preventive/reconstructive surgery, topographic pattern, gender, scoliosis (>40° or spinal fusion after TRC closure), epilepsy, ventriculoperitoneal shunt, and the presence of G-tube. An “unsuccessful hip” was defined by MP ≥30%, MP progression by ≥10%, and/or requiring reconstructive surgery after TRC closure. Statistical analyses included chi-square and multivariate Cox regression analyses. Kaplan–Meier survivorship was also determined. Receiver-operating characteristic (ROC) curve analysis was used to identify the MP threshold for progression to an unsuccessful hip after TRC closure.

Results: Seventy-six patients (39.5% female) met the inclusion criteria, with mean follow-up 4.7 ± 2.1 years after TRC closure. The age at TRC closure for females/males was 13.5(± 1.7)/14.2(± 1.7) years (p = 0.12). Sixteen (21.1%) patients had an unsuccessful hip outcome at final follow-up. By chi-square analysis, diplegia (p = 0.002) and the presence of epilepsy (p = 0.04) were risk factors for an unsuccessful hip. By multivariate analysis, only “first MP at TRC closure” (p < 0.001) was a significant risk factor for progression to an unsuccessful hip. The mean survival time for progression to an unsuccessful hip was higher for females (p < 0.02). A first MP at TRC closure of ≥28% was associated with an unsuccessful hip at final follow-up (ROC analysis, area under the curve (AUC): 0.845, p < 0.02).

Conclusions: The risk of MP progression after skeletal maturity was still relatively high (21%), similar to non-ambulatory CP. Annual hip surveillance X-rays after TRC closure should continue for GMFCS levels I–III with an MP ≥28% after TRC closure, especially for bilateral CP, males, and for those with epilepsy.

Significance: The prevalence and risk factors for progressive HD after skeletal maturity can be used to inform hip surveillance programs for ambulatory CP.

EPOS/POSNA Abstract Book (26)

OP-47

How well does physical examination predict radiographic hip displacement in children with cerebral palsy?

Unni G. Narayanan, N. Susan Stott, Darcy Fehlings, H. Graham, Kishore Mulpuri, Benjamin J. Shore, M. Wade Shrader, Moon Seok Park, Tim Theologis, Marek Jozwiak, Jon R. Davids, Eva M. Ponten, Gunnar Hagglund, Bjarne Moeller-Madsen, Uri Givon, Deborah Eastwood, Tom F. Novacheck, Cerebral Palsy Hip Outcomes Project (CHOP)

The Hospital for Sick Children, Toronto, ON, Canada

LOE-Diagnostic-Level I

Purpose: Hip surveillance programs for cerebral palsy (CP) recommend standardized radiographs to identify hip displacement because physical examination is believed to be an unreliable predictor of hip displacement. The purpose of this study is to evaluate whether physical examination of hip range of motion can rule out or predict a clinically significant hip displacement (migration percentage > 30%).

Methods: The CP Hip Outcomes Project (CHOP) is a long-term prospective cohort study of patients (2–18 years old) enrolled from 28 sites in 10 countries evaluating the comparative effectiveness of different management strategies for hip displacement in non-ambulant children with CP (Gross Motor Function Classification System (GMFCS) IV and V). A total of 622 children enrolled prospectively in CHOP were evaluated at baseline for range of motion (ROM: R1 and R2) of hip abduction with hips and knees flexed; hip abduction with hips and knees extended; hip flexion contracture; and popliteal angles. ROM assessments were correlated with the respective MPs of each hip measured from the standardized AP radiograph of the pelvis, using linear regression, with analysis conducted for each side. Receiver operating curves were created for each specific ROM with area under the curve (AUC) reported to quantify the power of each test to predict MP ≥30%.

Results: Mean (range) age of the cohort was 6.9 (2–18) years. Mean MP was 58% (0%–100%) on each side. There was a non-linear relationship between hip abduction (R1 and R2) and MP. Ranges of motion > 30° had little correlation with the MP. When abduction was less than 25°, there was a stronger negative correlation between ROM and increasing MP (see Figure). However, the predictive value of the ROM was poor with an AUC of only 54%–59%, respectively, for R1 and R2 of hip abduction both with knees flexed or extended (see Figure). The knee popliteal angle fared worse with AUC of just over 50%.

Conclusions: This study confirms empirically in a large prospectively collected data set that the physical examination based on the ROM of the hip is a poor predictor of hip displacement, justifying the rationale of radiographs for hip surveillance programs in CP.

Significance: Evaluation of the range of motion during hip surveillance might still have clinical utility to inform indications for, and decision making about, specific interventions such as spasticity management or muscle contracture releases based on the type and magnitude of these contractures, but should not be used to predict hip displacement in CP.

EPOS/POSNA Abstract Book (27)

OP-48

Femoral head shaft angle changes based on severity of neurologic impairment in children with cerebral palsy and spinal muscle atrophy

Luiz Carlos Almeida Da Silva, Yusuke Hori, Burak Kaymaz, Kenneth Rogers, Arianna Trionfo, Jason Howard, J. Richard Bowen, M. Wade Shrader, Freeman Miller

Nemours Alfred I. Dupont Children’s Hospital, Wilmington, DE, USA

LOE-Not Applicable-Level III

Purpose: Guided growth of the proximal femur (PFGG) is a treatment option for coxa valga deformity in children with cerebral palsy (CP). Understanding proximal femoral geometric features by functional level is important to provide a rationale for the use of guided growth as a potential intervention for hip displacement. This study evaluates the neck shaft angle (NSA) and the head shaft angle (HSA) in children with different levels of neurological disability.

Methods: Medical records and pelvic radiographs of children aged 1–12 with a diagnosis of spastic CP, spinal muscular atrophy (SMA) I-II, or typical development from 2006 to 2021 were reviewed to evaluate the NSA and HSA. Patients were divided into five groups: Gross Motor Function Classification System (GMFCS) I-II, GMFCS III, GMFCS IV-V, SMA 1-2, and typical development. A linear mixed model (LMM) was utilized to evaluate NSA and HSA within the groups during the growth.

Results: In total, 196 consecutive children with multiple visits were included. The distribution and measurement of children were: GMFCS I–II 8 children (33 hip evaluations, NSA 143.7 ± 7.4, HSA 160.0 ± 7.1), GMFCS III 22 children (130 hip evaluations, NSA 153.1 ± 4.3, HSA 163.4 ± 4.2), GMFCS IV–V 30 children (137 hip evaluations, NSA 156.4 ± 5.6, HSA 167.9 ± 6.8), SMA 1–2 32 children (83 hip evaluations, NSA 161.9 ± 9.7, HSA 173.4 ± 7.4), and typical development 104 children (222 hip evaluations, NSA 138.6 ± 7.0, HSA 156.4 ± 5.9). Mean age of all children was 4.8 ± 4.5 years (range: 0.4–12.78 years). Typical development group had NSA lower than SMA 1–2, GMFCS III, and GMFCS IV–V groups. GMFCS I–II group had lower HSA than GMFCS IV–V. Typical development group had NSA lower than SMA 1–2, GMFCS III, and GMFCS IV–V groups (Figure). GMFCS I–II had lower NSA than GMFCS III and GMFCS IV–V. LMM shows that there are significant statistical differences when comparing NSA and HSA among the groups.

Conclusions: As children grow, NSA and HSA tend to decrease in typical development and GMFCS I–II groups. However, in low-tone groups (SMA 1–2) and high-tone groups (GMFCS IV–V), NSA and HSA tend to increase with age. In both low-tone and high-tone groups, coxa valga is observed. Using PFGG may help change the course of HSA and NSA in both low- and high-tone groups.

Significance: PFGG relies on anatomical parameters to correct the coxa valga deformity. Understanding NSA and HSA for different levels of neurological impairment may assist with diagnostic tools, aid in treatment planning, and help monitor the progress of interventions.

EPOS/POSNA Abstract Book (28)

OP-49

Proximal femur guided growth for spastic hip displacement in cerebral palsy children—long-term follow-up

Wei-Chun Lee, Szu-Yao Wang, Hsuan Kai Kao, Wen-E Yang, Chia-Hsieh Chang

Chang Gung Memorial Hospital, Taipei

LOE-Therapeutic-Level IV

Purpose: Proximal femur guided growth by an eccentric transphyseal screw has been used to treat spastic hip displacement in cerebral palsy children. However, there was no long-term follow-up outcome for this inventive treatment. The purpose of this study was to report postoperative long-term results.

Methods: This case series study included consecutive patients who received soft-tissue release and guided growth at the proximal femur from 2005 to 2014 with more than 5-year follow-up. Surgical indications were children with spastic cerebral palsy aged 4–12 years, gross motor function classification system level III, IV, or V, and hip displacement noted on X-ray image. Parameters include Reimer’s migration percentage (MP) which was compared between preoperative and postoperative 1 year, 2 years, 5 years, and last follow-up pelvis X-ray image.

Results: Sixteen children with 30 spastic hip displacements received guided growth surgery and soft tissue release in the study period. The mean operation age was 7.4 years, and the mean follow-up duration was 9.4 years. The mean pre-operative MP of the 30 hips was 46.5%. The mean MP in the post-operative 1, 2, 5 years and last follow-up was 37.8%, 36.4%, 26.1%, and 26.6%. The changes of MP were statistically significant between preoperative and postoperative 5-year and last follow-up. After guided growth, only two patients received proximal femur varus osteotomy to treat residual spastic hip displacement.

Conclusions: Although not as acute and definite as varus osteotomy, the correction effect by the guided growth on proximal femur was encouraging in our study. Less surgical dissection and hospital stay, less complication, and faster recovery of motion make the guided growth surgery a treatment option for cerebral palsy children with spastic hip displacement.

Significance: This study reported the long-term follow-up results of guided growth in the capital femoral physis for spastic hip displacement in cerebral palsy children.

OP-50

Does the addition of proximal femoral epiphysiodesis in neuromuscular hips improve caput valgum?

M. Bryant Transtrum, Katelyn S. Rourk, Julia Todderud, Christina Regan, Anthony A. Stans, William J. Shaughnessy, A. Noelle Larson, Todd A. Milbrandt, Emmanouil (Manos) Grigoriou

Mayo Clinic, Rochester, MN, USA

LOE-Therapeutic-Level III

Purpose: Children with cerebral palsy (CP) are at an increased risk of developing progressive neuromuscular hip subluxation and potential dislocation due to altered muscle forces across the hip joint. Progressive neuromuscular hip displacement can lead to altered spino-pelvic mechanics and eventual hip pain and arthritis, imposing challenges for both patients and caregivers. This current study aims to evaluate the potential additive protective role of proximal femoral epiphysiodesis (PFE) after varus derotation femoral osteotomy (VDRO) in preventing recurrent coxa valga in CP patients with progressive neuromuscular hip disease.

Methods: We conducted a retrospective study of pediatric patients with CP who underwent a combined staged treatment approach involving VDRO at index surgery and PFE at the time of hardware removal at a tertiary pediatric orthopedic hospital between 2007 and 2022. We evaluated radiographic hip progression at four distinct time points: initial presentation, post-VDRO, post-PFE, and latest follow-up. Radiographic progression of the included hips was evaluated by measuring the acetabular index (AI), lateral center-edge angle (LCEA), neck-shaft angle (NSA), physeal tilt (PT), head-shaft angle (HAS), and migration percentage (MP) at all time points.

Results: Twenty-one hips in 12 patients were included with a mean follow-up of 6.5 years (2.1–10.5, ± 2.5). The average age at VDRO was 6.2 (3.6–12.7, ± 2.3) and PFE was 7.2 (4.2–12.7, ± 2.0). Significant radiographic improvements in all measurements were observed following VDRO. Similar improvements were not observed after PFE at latest follow-up of 6.5 years (2.1–10.5, ± 2.5) (see Table 1).

Conclusions: Our findings suggest that while VDRO is effective in improving radiographic measurements in CP patients with neuromuscular hip dysplasia, the addition of PFE does not provide further radiographic benefits at an average follow-up of 6.5 years (2.1–10.5, ± 2.5 years). Large-scale prospective studies are needed to further delineate the role of PFE and help us refine our treatment strategies for this patient population and their families.

Significance: Previous studies have investigated the benefits of both procedures individually, but there is limited knowledge regarding the additive effects of PFE following VDRO. We sought to address this gap in the literature, and we found that while VDRO led to significantly improved radiological outcomes for every measurement, PFE yielded no additional significant improvements at latest follow-up. These results can help guide caregiver counseling and can aid providers in surgical planning.

EPOS/POSNA Abstract Book (29)

OP-51

Medialization at the osteotomy site may reduce relapse after varus de-rotational osteotomy (VDRO) of the proximal femur in cerebral palsy

Frederico Vallim, Eduardo Duarte Pinto Godoy, Juliana Lyra, Joao Antonio Matheus Guimaraes, Marcello Henrique Nogueira-Barbosa, H. Graham

Hospital Estadual da Criança, Rio de Janeiro, Brazil

LOE-Therapeutic-Level II

Purpose: Non-ambulatory children with cerebral palsy have a high prevalence of hip dislocation, which may cause pain, seating, and perineal hygiene difficulty, contributing to scoliosis and pelvic obliquity. Surgical treatment includes procedures like proximal femoral reorientation by varus de-rotational osteotomy (VDRO). However, recurrent hip instability can be as high as 77% between index surgery and skeletal maturity. We evaluated the association between femoral diaphyseal medialization at the VDRO site and the recurrence of hip displacement. We hypothesized that medialization modifies the resultant forces around the hip, reducing the femoral remodeling that leads to recurrent instability.

Methods: We retrospectively evaluated the medical and radiographic records of 138 patients (276 hips) with cerebral palsy (CP), GMFCS IV or V, and followed until skeletal maturity (average 11.3 years). All patients had been registered on the Statewide CP Register (SCPR) and managed by bilateral femoral VDRO as index surgery, between 1998 and 2012. Radiographic measurement of medialization was performed using the medialization index (MeI) described by Davids et al. (2013), preoperatively, at 6 weeks, at 12 months post-surgery, and at skeletal maturity. Failure or relapse of instability was defined as the need for revision surgery before skeletal maturity or final migration percentage (MP) > 40%. The influence of MeI was determined by Poisson regression with multiple variances. Inter and intra-observer reliability of MeI was assessed by 4 different observers in 72 hip radiographs using Cohen’s D test. Finally, medialization was bench tested in synthetic models to evaluate its stability, with system rigidity and deformation compared by analysis of variance (ANOVA) and logistic regression.

Results: Groups with and without relapse were comparable pre-operatively regarding femoral morphological parameters and acetabular index. Baseline MP was higher in the relapse group (p < 0.001). MeI at 6 weeks post-surgery differed significantly between groups, being lower in the relapse group (p = 0.004, risk ratio (RR) = 0.07; confidence interval (CI) = 0.01–0.42), considering confounding factors, including pre-operative MP. MeI showed good inter and intra-observer reliability with D inferior to 0.5 in all tests. Finally, the medialization of the diaphysis did not cause system failure clinically or instability in mechanical testing.

Conclusions: Patients with more femoral diaphysis medialization had reduced recurrence of hip instability in long-term follow-up. MeI proved to be radiographically reliable, and medialization did not increase mechanical instability.

Significance: Osteotomy medialization at VDRO site can be controlled by implant selection and surgical technique. This study suggests that medialization may reduce recurrence of hip instability in non-ambulatory CP patients, after VDRO.

EPOS/POSNA Abstract Book (30)

OP-52

Combined pelvic osteotomy and proximal femur guided growth for serious hip subluxation in cerebral palsy children

Kuan-wen Wu, Hsiang Chieh Hsieh, Chia-Che Lee, Ting-ming Wang, Ken N. Kuo

National Taiwan University Hospital, Taipei

LOE-Therapeutic-Level III

Purpose: Guided growth of proximal femur has been shown to be feasible to stabilize the hip subluxation in cerebral palsy (CP) children. However, in those with higher migration percentage (MP), guided growth alone might not suffice. This study addresses whether additional pelvic osteotomy can provide early hip stability and prevent further subluxation in CP children with serious hip displacement.

Methods: We retrospectively studied data on CP children who underwent combined guided growth and pelvic osteotomy from 2016 to 2020 at a single institution. The indications for surgery were MP >40% and head-shaft angle (HSA) >155° with acetabular dysplasia (acetabular index (AI) > 22°). There were 26 consecutive CP children (12 boys and 14 girls; 42 hips) who underwent index procedures with a minimum of 2-year follow-up. The mean age at surgery was 6.3 years. Radiographic parameters including the HSA, AI, center-edge angle (CEA), Hilgenreiner’s epiphyseal angle (HEA), and Reimer’s MP were assessed before surgery and at 6 months, 1 year, 2 years, and final visit after surgery.

Results: All radiographic measurements had statistical improvement in terms of the mean reduction of HSA by 9° ± 8° (p < 0.001), the AI by 9° ± 6° (p < 0.001), and the MP by 28% (p < 0.001) at final visit. The HSA continued to steady decline after surgery, with lower HSA in patients with more follow-up times (p < 0.001), older age at surgery (p = 0.007), and milder GMFCS level (p < 0.001). However, the AI and MP had an immediate reduction at 6-month follow-up and continue to slow decline until the latest visit. We also found that the 19 of 42 hips required a longer screw change due to physis grew off the screw tip. The four of 42 of hips who had a latest MP > 50% were considered poor outcome. They were GMFCS IV and V and three hips had a severe baseline MP ≥80%.

Conclusions: The combined guided growth and pelvic osteotomy provide hip stability with immediate improvement of AI and MP, while guided growth takes time to correct coxa valgus. It is an effective strategy in CP children with avoidance of multiple osteotomies.

Significance: The study may be the first one to demonstrate the encouraging results of combined procedures in CP children with serious subluxation. Further study is necessary to determine the optimal timing of intervention and develop an algorithm for unstable CP hips.

EPOS/POSNA Abstract Book (31)

OP-53

Medium-term results after femoral head resection and subtrochanteric valgus osteotomy in children and adolescents with cerebral palsy

Ralf D. Stuecker, Madeleine Marowsky, Oliver Jungesblut, André Strahl, Martin Rupprecht

Childrens Hospital Hamburg-Altona, Hamburg, Germany

LOE-Therapeutic-Level IV

Purpose: Various salvage surgical procedures for painful hip dislocation in adolescent patients with cerebral palsy (CP) exist. In our institution, the McHale procedure is the standard of care for painful chronically dislocated hips with or without deformity of the femoral head in non-ambulatory patients with CP. This study focuses on mid-term results after surgical treatment.

Methods: Surgical reports and patient charts were analyzed retrospectively. All X-rays were evaluated and migration of the proximal femur and heterotopic ossification (HTO) according to Brooker were recorded. In addition, we conducted a telephone interview with the caretakers with special reference to pain pre- and postoperatively and after implant removal, sitting tolerance, range of motion, mobility, quality of life, and personal hygiene.

Results: Fifty-two patients (65 hips) with a mean age of 13.5 ± 3.6 years (range: 4–20 years) were included. Mean surgery time was 178.4 ± 63.4 min (range: 45–380 min) and mean follow-up was 45.17 ± 30.6 months (range: 12–204 months). A significant difference between pre- and post-operative pain levels was found, p < 0.001. Personal hygiene (p = 0.02) and quality of life (p = 0.013) improved significantly. Eighty-five percent of the caregivers would have the surgery performed on their child again and 81% of the caregivers would recommend the surgery to others. The removal of implants leads to a significant improvement in pain (p = 0.011). A total of 22 complications in 65 McHale procedures (33.9 %) were related to the procedures.

Conclusions: A significant reduction in pain and a significant improvement in hygiene as well as quality of life can be achieved with the McHale procedure in painful chronically dislocated hips in patients with cerebral palsy. Overall, the procedure is predominantly experienced as helpful by the caregivers and recommended to others. The removal of the implants improves pain significantly, but complications may occur in one third of the patients.

Significance: Medium-term follow-up data after McHale procedures are very encouraging. However, further studies to assess long-term outcomes after such procedures are needed.

OP-54

The association between hip displacement, scoliosis, and pelvic obliquity in 106 non-ambulatory patients with cerebral palsy: a longitudinal, population-based study

Terje Terjesen, Svend Vinje, Thomas Kibsgård

Oslo University Hospital, Rikshospitalet, Oslo, Norway

LOE-Not Applicable-Level II

Purpose: The relationship between hip displacement (HD), pelvic obliquity (PO), and scoliosis in non-ambulatory children with cerebral palsy (CP) has not been clearly elucidated. The aims of this longitudinal, population-based study were to examine the prevalence and temporal sequence of these deformities and to evaluate how probable it is that severe unilateral HD could be the cause of scoliosis.

Methods: The study comprised 106 non-ambulatory children (37 girls and 69 boys) with bilateral CP, born between 2002 and 2006, at Gross Motor Function Classification System (GMFCS) level IV or V, and enrolled in a surveillance program. Pelvic radiographs for measurements of migration percentage (MP) and PO were taken once a year from the diagnosis of HD. Spinal radiographs were taken in patients with clinical scoliosis. Only clinically significant deformities, defined as scoliosis with Cobb angle ≥40°, HD with MP ≥40%, and supine position PO ≥5°, were included in the analyses.

Results: Scoliosis occurred in 60 patients (57%) at a mean age of 11.8 years (5.3–16.3 years). Sixty-five patients (61%) developed HD at a mean age of 4.8 years (range, 0.7–12.5 years). Thirty-three children (31%) had PO in the supine position ≥5° at the latest follow-up; the mean PO was 10.4° (5°–30°). Nineteen patients had no deformities, 35 had 1 deformity, 33 had 2 deformities, and 19 patients had 3 deformities. The temporal sequence showed that HD was diagnosed before scoliosis in all except 2 of the 43 patients with both deformities. Thirteen of 17 patients (74%) with severe unilateral HD (MP ≥ 60%) had scoliosis convexity to the opposite side of the displaced hip.

Conclusions: The combination of clinically significant scoliosis and HD occurred in 41% of non-ambulatory children, and HD was diagnosed first in most of these patients. In children with severe, unilateral HD and PO, HD was probably a contributing cause of scoliosis.

Significance: The surveillance of scoliosis in children with CP needs improvement to detect the deformity earlier. In children at GMFCS levels IV/V, a routine spine radiograph should be taken at an age of 5–6 years. If scoliosis occurs in young children, a spinal orthosis could be tried temporarily, providing improved sitting balance, head/neck control, and hand function until the child gets old enough for surgical correction.

OP-55

The evaluation of total hip replacement in management of spastic painful hip dislocation in cerebral palsy

Andrzej Sionek, Bartosz Babik, Jaroslaw Czubak

Department of Orthopedic, Pediatric Orthopedic and Traumatology, Gruca Teaching Hospital CMKP, Warsaw-Otwock, Masovia, Poland

LOE-Therapeutic-Level III

Purpose: Spasticity used to be considered as a contraindication for total hip replacement (THR). Due to the development of implants as well as surgical skills, THR became an option of treatment of painful dislocation of the hip joint in patients with spastic plegia. The aim of this study was an evaluation of mid-term results of THR in spastic cerebral palsy (CP) adolescent patients with painful hip with hip joint subluxation or dislocation.

Methods: In 2014–2022, 18 patients (19 hips) with CP between the ages of 16 and 20 years underwent THR in our department. The mean follow-up was 4 years (range, 1–9 years). Results were examined with Gross Motor Function Scale, VAS scale in accordance with Ashworth scale, types of implants used (dual mobility cup and not dual mobility cup), and radiological factors (Crowe scale). Complications were noted.

Results: In case of 10 patients, there was improvement in Gross Motor Function Classification System (GMFCS) scale average from 1 to 2 points after surgery. In all patients, improvement was observed in VAS scale average 8 points (from 10 to 7) According to Crowe scale, reposition of preoperative dislocation to primary acetabulum was achieved in all cases. Complications occurred in four cases: dislocation of two THR with dual mobility cup and two THR with non-dual mobility cup requiring revision surgery with good final result. No statistical significance was noted according to the type of cup (Mann–Whitney U test).

Conclusions: Increased risk factors of complications are severe spasticity. We believe that CP patients with painful hip should be treated using THR. We did not observe any differences between the type of implant.

Significance: These findings may serve as a basis for prediction of outcomes of THR treatment in this group of patients.

OP-56

Inter-rater reliability of a photo-based modified foot posture index (MFPI) in identifying severity of foot deformity in children with cerebral palsy

Beltran Torres-Izquierdo, Jason Howard, Sean Tabaie, Mara S. Karamitopoulos, Benjamin J. Shore, Monica Payares-Lizano, Robert Lane Wimberly, M. Wade Shrader, Kristan A. Pierz, Andrew Gregory Georgiadis, Jason Rhodes, Jon R. Davids, Rachel Mednick Thompson, Pooya Hosseinzadeh

Washington University School of Medicine, Saint Louis, MO, USA

LOE-Not Applicable-Level V

Purpose: Children with cerebral palsy (CP) have high rates of foot deformity. Accurate assessment of these deformities is crucial for therapeutic planning and outcome evaluation. This study aims to evaluate the reliability of a novel photo-based Modified Foot Posture Index (MFPI) in the neuromuscular patient population.

Methods: In this multicenter study, 12 orthopedic surgeons from 12 institutions evaluated standardized photographs of feet from 20 children with CP and scored their deformities using the MFPI. Raters scored photographs based on five parameters: for the hindfoot, curvature above and below the malleoli and calcaneal inversion/eversion were assessed and scored; for the forefoot, talonavicular congruence, medial arch height, and forefoot abduction/adduction were similarly evaluated and scored. Summary of MFPI scores range from −10 to +10, where a positive number connotes a tendency toward planovalgus while a negative number connotes a tendency toward cavovarus. Inter-rater reliability was determined using a two-way mixed model of the intraclass correlation coefficient (ICC) set to absolute agreement.

Results: According to the MFPI, feet examined spanned the spectrum of potential pathology, including no deformity, mild, and moderate deformities. The inter-rater reliability for various components of the MFPI was evaluated, and the findings are summarized in Table 1. All scored variables showed high inter-rater reliability with ICC ranging from 0.965 to 0.984. Rear foot total score had a mean of 0.97, an ICC of 0.979, and a confidence interval (CI) of 0.968–0.988 (p < 0.001). The forefoot total score was 2.12 with an ICC of 0.984 and a CI of 0.976–0.991 (p < 0.001). Finally, the overall total for the MFPI was mean 3.67 with an ICC of 0.982 and a CI of 0.972–0.990 (p < 0.001).

Conclusions: The photo-based MFPI demonstrates high inter-reliability in assessing foot deformities in children with CP, with specific high reliability in both rear foot and forefoot assessments. Its non-invasive nature and ease of use make it a promising tool for both clinical and research settings, especially in prospective studies evaluating the outcomes of foot reconstruction.

Significance: In addition to radiographic and patient-reported outcomes, MFPI should be adopted as part of standard outcomes scores in studies regarding the treatment of CP-associated foot deformities.

EPOS/POSNA Abstract Book (32)

OP-57

Impact of femoral derotation osteotomy and equinus varus foot correction on transverse plane asymmetry in patients with hemiplegic cerebral palsy

Mauro Cesar Morais Filho, Marcelo Hideki Fujino, Catia Miyuki Kawamura, Jose Augusto Fernandes Lopes, Fernanda Piumbini Azevedo

AACD, São Paulo, Brazil

LOE-Therapeutic-Level III

Purpose: Our objective was to evaluate the impact of external femoral derotation osteotomy (FDO) and equinus varus foot surgical correction (EVFSC) on transverse plane asymmetry in patients with spastic hemiplegic cerebral palsy (SHCP).

Methods: Patients with SHCP, with two or more gait analyses and with pelvic asymmetry at baseline were included. A total of 453 participants were identified; however, those with mixed tone (n = 45), other pathologies combined with hemiplegia (n = 11), previous orthopedic surgeries (n = 248), pre-operative gait analysis performed more than 2 years before surgery (n = 12), and those who underwent other surgical procedures (n = 47) were excluded. The remaining 90 patients were divided into 4 groups according to the surgical procedure: Control Group (CG)—no surgery (n = 21); FDO (n = 7); EVFSC (n = 40); and FDO + EVFSC (n = 22). Age at surgery, follow-up time, and baseline Gait Deviation Index (GDI) were compared. GDI, pelvic asymmetry (PA) in the transverse plane, internal hip rotation (IHR), and foot progression angle (FPA) in kinematics were analyzed at baseline and at the final follow-up, and the intra- and inter-group results were compared.

Results: The four groups matched in age at surgery (12.4–16.7 years) and follow-up time (34.5–66 months). At the final follow-up, a GDI reduction in the CG (3.6) and an increase in the other groups (7.7 in FDO, 10 in EVFSC and 21.8 in FDO + EVFSC) were observed. GDI improvement was greater in the FDO + EVFSC group than in the other groups (p < 0.001). The reduction in PA in the transverse plane was higher in the FDO + EVFSC group (15.3°) than in the EVFSC (5°, p = 0.007) and CG (1.2°, p = 0.001) groups. Regarding IHR, we observed a decrease in the FDO + EVFSC (17°), EVFSC (4.6°), and FDO (3.1°) groups, whereas the CG group exhibited a mild increase (1.1°). The reduction in IHR in the FDO + EVFSC group was greater than that of the other groups (p < 0.001). Finally, the reduction in internal FPA was similar in the FDO + EVFSC (18.6°, p = 0.002) and EVFSC (12.7°, p = 0.021) groups.

Conclusions: The combination of external FDO and EVFSC produced the greatest reduction in IHR and increase in GDI. Groups receiving EVFSC exhibited a greater reduction in internal FPA. Finally, the reduction in PA in the transverse plane was higher in the FDO + EVFSC groups than in the EVFSC or CG group, and it was similar to that of the FDO group.

Significance: Asymmetry in transverse plane is frequent in patients with SHCP and increased IHR and EVF deformity have been implicated as possible causes.

OP-58

Aspirations dashed: serum neutrophil-to-lymphocyte ratio is not a good predictor of septic arthritis of the hip and knee in pediatric patients

Christopher John DeFrancesco, David Peter VanEenenaam, Carter Hall, Vineet Desai, Kevin Jossue Orellana, Wudbhav N. Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Diagnostic-Level II

Purpose: Recent research in adults suggests that serum neutrophil-to-lymphocyte ratio (S-NLR) is a superior diagnostic criterion for pyogenic septic arthritis (SA) compared to synovial fluid white blood cell count (SF-WBC) >50,000 cells/mm3 or >90% polymorphonuclear leukocytes (%PMN). However, it is not known whether this finding extends to pediatric patients.

Methods: Medical records at a large urban tertiary care children’s hospital were queried for emergency department visits between 2012 and 2022 where an aspiration was performed to evaluate for SA of the hip or knee. Patients ≥18 years old were excluded. Patients were considered “positive” for SA if synovial fluid analysis showed any of the following: (1) SF-WBC > 50,000 cells/mm3, (2) > 90% PMNs, or (3) organisms reported on gram stain. This was termed the “composite test.” Cases where aspirate and/or operating room (OR) cultures revealed an offending organism were considered culture-positive septic arthritis (CPSA). Serum and synovial fluid test data were compared to assess their diagnostic utility. Receiver-operating characteristic (ROC) curves were examined to compare the predictive value of S-NLR compared with traditional indicators of SA.

Results: In total, 392 cases met the inclusion criteria (Figure 1A). Those with CPSA had higher ESR and CRP compared to culture negative patients (p = 0.01 and p < 0.01, respectively). Univariate testing showed no difference in S-NLR between those with CPSA and those without CPSA (p = 0.97). ROC analysis for the diagnosis of CPSA showed no difference between S-NLR and SF-WBC as diagnostics (area under the curve (AUC) = 0.68 versus 0.63, respectively, p = 0.42, Figure 1B). S-NLR was also not found to be a predictor of CPSA (p = 0.90) in the 126 cases where the composite test was negative. Among patients with negative cultures, 38% had positive Lyme serologies.

Conclusions: In contrast to adults, S-NLR is not a good indicator of SA of the hip or knee in children. This may be because competing diagnoses in children (e.g. Lyme) come with systemic humoral inflammatory responses—and increased S-NLR—similar to that seen in pyogenic SA, while noninfectious/degenerative conditions that might represent the major alternate diagnosis in adults do not increase S-NLR significantly. Given regional variations in the incidence of Lyme disease, this topic should be further studied at centers outside Lyme-endemic areas.

Significance: Despite excitement regarding S-NLR as a diagnostic for adult SA, this criterion appears less useful in the diagnosis of pyogenic SA in pediatric patients.

EPOS/POSNA Abstract Book (33)

OP-59

Severity of osteomyelitis—the bug is the problem

Haemish A. Crawford, Anna McDonald, Simon Swift, Jillian Cornish, Reece Joseph, Sophia Huiyao Hamada-Zhu, Christina Straub, Brya Matthews

Starship Children’s Hospital, Auckland, New Zealand

LOE-Prognostic-Level II

Purpose: Pediatric acute hematogenous osteomyelitis (PAHO) infections in New Zealand are often caused by methicillin-susceptible Staphylococcus aureus (MSSA), and flucloxacillin is frequently used as a first-line treatment antibiotic. While most PAHO cases can be successfully treated with antibiotics, some patients respond poorly and/or require prolonged treatment despite their infecting bacteria having shown susceptibility in a laboratory setting. Other factors may contribute to antibiotic failure, such as the ability of S. aureus to form biofilms. Currently, there is a knowledge gap in how biofilm formation may be linked with antibiotic effectivity in PAHO. However, it is hypothesized that biofilms may influence antibiotic failure and poor clinical outcomes by shielding bacteria from antibiotics and giving bacteria the potential to become antibiotic-tolerant persister cells. Or is it due to increased virulence of the bacteria itself?

Methods: We sequenced 85 PAHO isolates from patients at Starship Hospital collected between 2008 and 2017 using short-read technology. Our institution is unique in that all bacteria causing PAHO over this period are stored in our “bio bank.” These bacteria were available for further analysis. The patient’s clinical course was classified as complicated or uncomplicated. A. Complicated: pediatric intensive care unit (PICU) admission, Chronic or recurrent osteomyelitis, >8 weeks antibiotics. B. Uncomplicated: resolved with no major complication and maximum 1 operation, <6.5 weeks antibiotics. The microbiologists performing the bacterial analysis were blinded to the classification of the patient’s clinical outcome. Genomes were sequenced using multiplexed SeqWell libraries run on two HiSeq lanes and assembled with SKESA.

Results: Analysis to explore whether there are bacterial gene markers beyond antibiotic resistance that correlate with treatment failure found that increased carriage of LukS Panton/Valentine Leukocidin was associated with complications in treatment (84% complicated, 19% uncomplicated isolates). All nine PICU patients had increased LukS Panton/Valentine Leukocidin. In addition, there appears to be a correlation with a shift in the carriage of the type 8 capsule serotype-specific genes over the type 5 capsule serotype-specific genes (cap8HIJK versus cap5HIJK). Complicated 7% Type 5: 93% Type 8 Uncomplicated 38% Type 5: 62% Type 8.

Conclusions: MSSA that causes complicated PAHO have a significantly increased carriage of LukS Panton/Valentine Leukocidin and a higher carriage of type 8 capsule serotype-specific genes when compared to MSSA bacteria in children with uncomplicated PAHO.

Significance: Osteomyelitis remains a significant issue among children in New Zealand. Identifying bacterial genes associated with poor outcomes in PAHO could help inform novel strategies for treatment in the future.

OP-60

Featherweight versus heavyweight of pediatric musculoskeletal infections: Kingella versus the titans of Staphylococcus and Streptococcus

Brian Quincey Hou, Malini Anand, William Franklin Hefley, Katherine Sara Hajdu, Stephen Chenard, Anoop Chandrashekar, Naadir Jamal, Michael Joseph Greenberg, Courtney Baker, Stephanie N. Moore-Lotridge, Jonathan G. Schoenecker

Vanderbilt University Medical Center, Nashville, TN, USA

LOE-Prognostic-Level III

Purpose: Pediatric musculoskeletal infections (MSKIs) are common invasive infections that account for, on average, 1 in every 10 consultations to a pediatric orthopedic provider at a tertiary care center. MSKIs may cause rapid decompensation and severe complications if not triaged and treated appropriately. Complications from these infections can be severe and often involve thromboembolic processes that lead to multiorgan dysfunction and death. The epidemiological landscape of causative pathogens has evolved over time, with Kingella kingae rising in incidence alongside the mainstays of Staphylococcus aureus and Streptococcus pyogenes. However, many septic arthritis cases, regardless of pathogen, are managed similarly. We hypothesize that there are different characteristics in Kingella infections compared to Staphylococcus or Streptococcus infections, with less severe presentations of Kingella MSKIs that warrant alternative treatment.

Methods: A retrospective review of patients at a single academic tertiary care center identified 712 pediatric MSKIs from January 2013 to July 2022. Each record was reviewed to collect patient and disease characteristics as well as blood and tissue culture data. Patients without a confirmed infection resulting from Kingella, Staphylococcus, or Streptococcus were excluded.

Results: Patients with confirmed Kingella infection were significantly younger than those with confirmed Staphylococcus or Streptococcus infection (1.23 versus 7.98 versus 6.77 years, respectively, p < 0.0001). Kingella had a non-statistically significant increased propensity for the lower extremity (95.2%) compared to Staphylococcus (85.7%) or Streptococcus (77.3%). Moreover, Kingella infections induced a significantly milder inflammatory response compared to Staphylococcus or Streptococcus, with a lower admission C-reactive protein (mean, 41.3 versus 119.9 versus 100.0 mg/L, respectively, p < 0.0001) and higher admission platelet count (402.4 versus 304.0 versus 318.3, respectively, p = .0036). 92.3% of patients with disseminated disease and complications had a diagnosed Staphylococcus infection, while 3.8% had Streptococcus and none had a Kingella infection. As such, unlike those with Staphylococcus infections, no patients with Kingella or Streptococcus infections required supplemental oxygen.

Conclusions: Cases of diagnosed Kingella-caused pediatric MSKIs differ from cases of Staphylococcus or Streptococcus MSKIs. Patients with a MSKI resulting from Kingella are often younger and have a milder course of disease from MSKIs compared to patients with a Staphylococcus or Streptococcus MSKI.

Significance: Understanding the epidemiological trends in MSKI is critical for developing appropriate treatment pathways for pediatric MSKI. Differences in Kingella infection severity compared to other pathogens may indicate a need to reevaluate contemporary approaches to their treatments. Use of molecular detection methods may allow for expedited diagnosis of Kingella infections, setting the stage for new focused treatment algorithms.

EPOS/POSNA Abstract Book (34)

OP-61

Low prevalence of anaerobic bacteria in pediatric septic arthritis makes obtaining anaerobic cultures of questionable value

Maia Regan, David A. Spiegel, Kenneth Smith, Keith D. Baldwin

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Diagnostic-Level III

Purpose: Pediatric acute septic arthritis necessitates urgent identification and treatment to avoid irreversible joint damage if not recognized and treated in a timely fashion. Many centers routinely send both aerobic and anaerobic cultures for the purpose of pathogen identification; however, the yield of anaerobic culture results has been called into question. The goal of this study was to determine the positivity rate of anaerobic cultures collected intraoperatively in pediatric patients with a clinical diagnosis of septic arthritis.

Methods: Patients with a clinical diagnosis of septic arthritis were extracted from a search of musculoskeletal infections at a large tertiary care pediatric hospital from 2007 to 2021. We examined cultures obtained from the emergency room or operating room through arthrocentesis or intraoperative culture. These cultures are routinely obtained in both aerobic and anaerobic culture media at our institution. We assessed the cultures and the clinical scenario surrounding them to assess the utility of anaerobic cultures in the diagnosis and management of pediatric septic arthritis.

Results: We identified 466 cases of pediatric septic arthritis of which only 3 cultures were positive (0.6%) for anaerobic organisms, two involving a hip and one involving a shoulder (Table 1). All cases involved a single isolate. The anaerobic bacteria that were detected included one facultative anaerobe, one strict anaerobe, and one relatively aerotolerant anaerobe (Table 1). Four aerobic organisms grew on the anaerobic cultures. These included methicillin-resistant Staphylococcus aureus (2) and Staphylococcus (2). These four false positives also grew on aerobic culture media. Neither the facultative anaerobe nor the aerotolerant anaerobe grew on aerobic culture media.

Conclusions: Over a 14-year period, only 0.6% (3 cases) of septic arthritis cases yielded positive anaerobic cultures that were not able to be cultured on aerobic media. As such, an anaerobic culture was more likely to culture a bacterium that would have also been also cultured on aerobic media. In addition, a true positive anaerobic culture that would not have been diagnosed on aerobic cultures only occurs about once every 5 years at our institution.

Significance: These results suggest that routinely obtaining anaerobic cultures may be of limited value in pediatric septic arthritis. In our sample, a positive culture of strict or facultative anaerobe was exceedingly unusual. The false-positive rate of anaerobic labs exceeds that of true-positive cases. These results provide actionable opportunity to help guide clinician decision making in a more cost-effective and efficient management of pediatric septic arthritis.

EPOS/POSNA Abstract Book (35)

OP-62

Tiny humans versus a deadly disease: an epidemiologic review of necrotizing fasciitis in pediatric patients

Stephanie N. Moore-Lotridge, Samuel Johnson, Wendy Ramalingam, Jonathan G. Schoenecker

Vanderbilt University Medical Center, Nashville, TN, USA

LOE-Prognostic-Level III

Purpose: Necrotizing fasciitis (NF) is a rare but potentially life-threatening infection that can occur in both pediatric and adult patients. Urgent identification and differentiation of NF from other soft tissue infections is vital to prevent associated morbidity and mortality. To date, few studies have examined the diagnosis and treatment of necrotizing fasciitis in pediatric populations. Thus, most of the diagnosis, prognosis, and management recommendations have been based on adult data. The goal of this study was to examine the variance in epidemiology and outcomes of pediatric and adult patients with confirmed NF.

Methods: A retrospective review from a single tertiary center identified 354 patients with confirmed NF, 23 children (<17 years of age) and 331 adults. Records were individually verified for the presence of disease prior to inclusion. Demographics including age, gender, infection origin, comorbidities, causative microbe, patient presenting symptoms, and mortality rate were compared.

Results: Between children and adults with confirmed NF, similar rates of gender and ethnic distribution were observed. Upon admission, pain, erythema, and swelling were present at similar rates between cohorts. The origin and mechanism of infection were significantly different between cohorts with children experiencing extremity infections at double the rate of adults (73.9% versus 36.0%). Children presented with lower rates of NF from infected wounds (0.0% versus 25.8%) and higher rates of NF from puncture wounds (17.4% versus 8.1%) compared to adults. Tissue culture results were significantly different between cohorts with children developing culture-negative NF at more than five times the rate of adults (23.8% versus 4.6%, p < 0.01). Finally, children, along with having fewer comorbidities (p < 0.001), had more favorable outcomes with shorter length of stay and lower rates of amputation and multi-organ failure. Importantly, children also had lower mortality rates compared to adults (4.3% versus 19.8%, p < 0.01).

Conclusions: Cases of pediatric NF differ from those of adults with lower rates of comorbidities, different mechanisms of contracting NF, and higher rates of culture negativity. Future multi-center clinical studies are necessary to develop pediatric-specific (1) diagnostic criteria to allow us to detect NF and distinguish NF from other severe soft tissue infections, (2) prognostic algorithms to predict patient outcomes, and (3) clinical practice guidelines to direct optimal treatment.

Significance: The unique features of pediatric NF, coupled with the rapidly progressive nature and potentially devastating sequelae, should prompt high clinical suspicion even when a child lacks traditional risk factors, disease features, and/or culture results commonly found in adults with NF.

OP-63

Awake biopsy in pediatric patients with suspected musculoskeletal malignancy is safe, feasible, cost-effective and reduces time to tissue diagnosis

Huw R.F. Walters, Alpesh Kothari, Max Mifsud, Andrew Wainwright, Karen Partington

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

LOE-Diagnostic-Level III

Purpose: Biopsy under general anesthetic (BGA) has been the standard of care in pediatric patients with suspected musculoskeletal malignancy. Scheduling and undertaking BGA may lead to delays in histological diagnosis and increase patient and parental anxiety. In our UK-based tertiary sarcoma center, we have increasingly performed awake percutaneous ultrasound-guided biopsies (AUPB) in children in cases of suspected musculoskeletal bone and soft tissue tumors. The aim of this study was to evaluate the safety, feasibility, and cost-effectiveness of AUPB in children with suspected musculoskeletal tumors compared to conventional BGA.

Methods: A retrospective, institutional review board (IRB)-approved database review was undertaken on all consecutive pediatric biopsies (<16 years old) performed in a UK tertiary sarcoma center between March 2016 and March 2023. Data extracted included patient demographics, biopsy type, time to biopsy (TTB) (from decision being made), as well as duration of biopsy and associated complications. Procedure costings were also obtained. Comparison was made between patients undergoing AUPB versus BGA. The primary outcome measure was TTB. Secondary outcomes measures included diagnostic specimen rates, complications, and costs. Standard parametric and non-parametric statistical methods were undertaken (alpha < 0.05).

Results: Eighty-six patients were included in this study with 53 undergoing BGA versus 33 AUPB. AUPB was associated with a significant reduction in median TTB compared to BGA (3 days (interquartile range (IQR), 2–7) versus 5 days (IQR, 2–18 days), p = 0.037). There was no significant difference in diagnostic specimen rate in AUPB compared to BGA (96% versus 97.5% p = 0.86) There were no complications in either group and no procedural abandonment in the AUPB group. Fifty-eight percent of patients undergoing AUPB had their biopsy on the same day as their initial assessment in clinic. AUPB conferred a reduction in financial cost of £647 per patient (£1177 versus £1824, p < 0.001). The mean age of patients undergoing AUPB was older than BGA (13.2 years (range, 5–16 years) versus 8.5 years (range, 3 months–15 years), p < 0.001).

Conclusions: Awake ultrasound-guided biopsy in suspected pediatric musculoskeletal tumors is an efficient, safe, well-tolerated, and cost-minimizing diagnostic tool. Its use reduces the time to obtain a histological diagnosis compared to biopsy under general anesthetic. While it may not be suitable for all children, this method is feasible and an important part of the diagnostic armamentarium.

Significance: Collaboration between clinicians and radiologists in identifying suitable patients for AUPB can facilitate efficient one-stop clinics, timely diagnosis, and reduce costs incurred in pediatric oncological services.

OP-64

Comparison of diaphyseal reconstruction techniques of the lower limbs in childhood malignant tumors: long-term results

Edouard Haumont, Lys Budiartha, Manon Pigeolet, Marine De Tienda, Frank Fitoussi, Stephanie Pannier, Eric Mascard

Necker—Enfants Malades, Paris, France

LOE-Therapeutic-Level III

Purpose: Osteosarcomas or Ewing’s sarcomas represent 90% of malignant bone tumors in children. The improvement of oncological resections and oncological treatments pushes orthopedists to improve their limb reconstructions. Endoprostheses seems to provide a significant complication rate, around 60% of cumulative complication. In biologic intercalary reconstruction, four techniques are described: vascularized fibula (VF), allograft and vascularized fibula (AVF), allograft alone (A), or induced membrane (IM).

Methods: This is a multicenter retrospective study. It concerns 93 (mean age, 12.3) patients with resection of primary malignant diaphyseal tumors between June 1986 and December 2017 and were included in French or European-chemotherapy protocols. Healing index (HI), functional score, and complications were investigated. The number of interventions was counted and compared between the different techniques. The minimal follow-up is 5 years.

Results: There were 53 osteosarcomas, 28 Ewing, and 12 other tumors, in 63 femurs and 30 tibias. Length of resection ranged from 18% to 88% of the bone length (mean 51%), with a mean length of resections was 19 cm (± 5.2 cm). Thirty-two patients had a VF, 13 had an AVF, 20 had an A, and 28 were treated with IM. Demographic data were comparable. Mean follow-up was 12 (5–25) years. Per primam consolidation was obtained in 57% of patients. Nine patients (9.5%) required amputation, seven due to local recurrence, one due to infection, and one due to mechanical failure. HI were comparable, but the average number of interventions per patient was 1.7 for AVF, 3.3 for VF, 3.3 for A, and 2.9 for IM. Four allograft resorptions were reported. In VF, 10 patients had donor-site complications (15%).

Conclusions: To our knowledge, no recent study offers a decision tree for choosing which technique for which resection. Functional results are good in all groups (MSTS mean: 85), comparison takes place on number of reoperations, complications, and time to consolidation. In femoral resections larger than 50% of bone length, AVFs provide good results. In tibias, VF and IM are comparable. However, IM leads to fewer reoperations and avoids donor-site complications. In IM non-unions, usually at proximal junction, fibula graft remained an option.

Significance: The significance of this study is its comprehensive patient cohort and long-term follow-up data to help inform decision making for individual malignant tumors patients.

OP-65

Survivorship of custom-made non-invasive extendable implants in pediatric sarcoma patients

Max Mifsud, Ruben Thumbadoo, Tim Theologis

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

LOE-Therapeutic-Level IV

Purpose: Osteosarcoma and Ewing’s sarcoma are the most common primary malignant bone tumors of adolescents. Unlike in adult patients, where non-custom non-extendable modular implants are typically used, in pediatric patients often custom-made non-invasive extendable implants (CMNIEI) are used. The survivorship of CMNIEI is not well documented. Previous research suggests that revision rates ranged from 39% to 47%, including revisions due to marked leg length discrepancies, and that on average patients underwent 2.7 further operations at a mean follow-up of 29.4 years. Complication and revision rates are important factors to consider in the management of these skeletally immature patients and this study seeks to add to that body of knowledge.

Methods: Retrospective case series between 2006 and 2023 of all skeletally immature patients with bone sarcoma treated by resection and reconstruction with CMNIEI by three surgeons within one nationally commissioned sarcoma unit. Patients with biological reconstructions were excluded. All prostheses were custom-made for each patient by Stanmore Implants Worldwide JTS®. Data were collected on type of tumor, type and length of bone resection performed, implant design characteristics, cementation techniques, complication rate, and revision surgery rate.

Results: Eighteen (9 male, 9 female) patients aged ≤16 years at the time of diagnosis were included in the study with minimum 2-year follow-up (mean = 56 months, range = 12–132). Fifteen had osteosarcoma and three had Ewing’s sarcoma. Mean age at the time of diagnosis was 11.6 years (range, 8–15 years). The mean resection length was 192 mm (range, 150–243 mm, femur n = 13, tibia n = 5). 77.8% of CMNIEI implants survived at least 56 months. Six of 18 patients (33.3%) suffered complications (fracture n = 1, arthrofibrosis, scar revision n = 3, other n = 1) and 4/18 (22.2%) required implant revision (revision of growing component n = 2, aseptic loosening n = 2). There were no cases of deep infection. Of those who needed implant revision, the mean implant survival was 50.1 months (range, 4.9–135.0 months), with the best implant survival in fully cemented implants. Six of 18 patients died of metastatic disease at a mean of 31.7 months after presentation.

Conclusions: 77.8% of implants survive at least 56 months. Although the rate of complications is high (33.3%), only four implants were revised (22.2%), at a mean of 50.1 months (range, 4.9–135.0 months). The lack of deep infections in our series (as opposed to the published rate of 6%–18%) likely contributed to better implant survivorship.

Significance: This information helps guide pre-operative discussions with patients/families. There is a high incidence of complications (33.3%) but overall low revision rate (22.2%).

OP-66

Sufficiency of isolated vascularized fibula for intercalary reconstruction

Laura Saenz, Sevan Hopyan

Hospital for Sick Children, Toronto, ON, Canada

LOE-Therapeutic-Level III

Purpose: Since survivors of childhood sarcoma may reach their elder years, the durability of limb reconstruction is important. Several methods for intercalary femoral and tibial defect reconstruction have been used. Allografts and endoprostheses are associated with a fairly high incidence of major revision and lifelong activity restrictions. Bone transport is a resurgent method of achieving living bone reconstruction that involves several additional procedures. Emerging evidence suggests that “single barrel” vascularized fibular free flaps (VFFF) are an alternative option for limb salvage. However, this approach remains uncommon because of uncertainty in the field about the complication profile, donor-site morbidity, and whether that reconstruction is mechanically sufficient for massive defects. Our main objective is to evaluate sufficiency and complications of intercalary reconstructions with a single-barrel VFFF with and without allograft.

Methods: Retrospective cohort study of 34 pediatric patients who underwent intercalary reconstruction for primary bone sarcoma of the lower extremity from 2005 to 2021 with minimum 2-year follow-up in one institution. To compare isolated vascularized fibular grafts to allograft or composite grafts (Capanna), we used descriptive and inferential statistical analyses using SPSS and classified complications according to the Clavien–Dindo System.

Results: Group No. 1 underwent reconstructions with allograft alone or combined with VFFF (n = 13) while Group No. 2 underwent reconstructions with a single-barrel VFFF alone (n = 21). No significant differences were found in gender, age (10.5 years versus 11.4 years), or diagnosis (osteosarcoma, Ewing sarcoma). Both groups had similar reconstruction length (21 cm), incidence of unplanned surgeries (4.2 versus 2.4) for complications (soft tissue, infection, fracture, hardware failure) except for nonunion which was significantly lower in Group No. 2 (19%) compared to Group No. 1 (38%, p = 0.025). Most complications in both groups required surgical intervention. All patients resumed full weight-bearing. Donor-site morbidity was not a substantive source of complications.

Conclusions: A single-barrel VFFF is not inferior and has at least one short/medium-term advantage regarding union compared to intercalary reconstruction using allograft or composite graft. Both groups had statistically similar rates of complications and unplanned surgeries. Full weight-bearing is readily achievable with a single-barrel VFFF even after massive reconstructions.

Significance: Since a VFFF restores living bone, the approach may allow for greater activity level, resistance to infection, and healing potential over several decades. Moreover, in regions worldwide where allografts are not available, intercalary reconstruction with VFFF is a feasible option.

EPOS/POSNA Abstract Book (36)

OP-67

Femoral head cartilage window approach combined with artificial bone implantation for treatment of epiphyseal chondroblastoma in children

Xuemin Lyu, Zheng Yang

Beijing Jishuitan Hospital, Beijing, People’s Republic of China

LOE-Therapeutic-Level IV

Purpose: Chondroblastoma of the femoral head epiphysis (CBFHE) is not an uncommon occurrence in children. Due to the vulnerability of the femoral head to necrosis and the potential for secondary deformity induced by the lesion, treatment poses a significant challenge. To address this concern, we sought to evaluate the impact of a simple and efficient method—the femoral head cartilage window approach combined with artificial bone implantation—on the growth of the femoral head.

Methods: Twenty-five cases of CBFHE were reviewed in our hospital. All patients were treated by the same surgical technique: anterior exposure of the femoral head was achieved using the Bikini approach. A cartilage window was opened in the weakest area of the lesion, which measured approximately 1.5 cm × 1 cm. The lesion was then curetted, followed by the implantation of artificial bone. The average age was 10.5 years (range: 6–14 years); 14 cases were male and 11 were female. Preoperative symptom duration was on average 6 months (range: 1–24 months). The Lodwick classification was used, showing two cases of class IA, 14 cases of class IB, and 9 cases of class IC. Nine cases presented invasion of the epiphyseal plate.

Results: Follow-up postoperative evaluation was conducted at 37 months (range: 22–84 months) and revealed no evidence of avascular necrosis or lesion recurrence. Femoral head deformity was observed in three cases, and two cases exhibited leg length discrepancies with shortening of 1.6 and 2 cm, respectively. Preoperative MSTS scores averaged at 21.5 (range: 16–24) and it improved to 28.7 (27–30) postoperatively (p < 0.05).

Conclusions: The combined approach of the femoral head cartilage window and artificial bone implantation represents a safe and effective method for treating CBFHE in children.

Significance: The combined approach of the femoral head cartilage window and artificial bone implantation could be an option for CBFHE in children.

OP-68

Evidence-based recommendations for treating pediatric desmoid tumors: consensus of the Desmoid Tumor Working Group*

Benjamin A. Alman, The Desmoid Tumor Working Group

Duke University, Durham, NC, USA

LOE-Economic-Not Applicable

Purpose: Desmoid tumors are locally invasive soft tissue lesions that frequently occur in the pediatric population. There have been substantial advances in diagnosis, natural history, and treatments in the past 5 years that have altered management. An international team used a formal process to develop evidence-based treatment recommendation for desmoid tumors with a sub-focus on the pediatric population.

Methods: Eighty-nine clinicians or researchers with expertise in desmoid tumors and leaders of patient advocacy groups were invited to participate. Data from a prior consensus paper was used as a baseline. New articles were assessed in several subtopics, and a meta-analysis was undertaken when appropriate data were available. A modified Delphi process was used with over 60 experts actively participating to develop recommendations.

Results: The diagnosis can be reliably by needle biopsy. Mutational analysis of the CTNNB1 gene, which encodes beta-catenin, should be undertaken to confirm the diagnosis. In mutation-negative cases, consideration should be given to genetic counseling or germ line APC mutational analysis, as these patients may have a form of familial adenomatous polyposis and routine colonoscopy is needed for surveillance. Almost a quarter of tumors will regress over time, and as such, active surveillance should be the first line of therapy unless a tumor is causing significant morbidity or has the potential for mortality. Surgery should be avoided, even in the smallest tumors, as recurrence rates are quite high, and overall outcome, as shown in meta-analysis, is worse than without surgery. In case of progressive or life-threatening situations, first-line therapy should be a methotrexate-vinblastine regimen. Tyrosine kinase inhibitors can be considered in the case of progression under this treatment. Studies on gamma secretase inhibitors in children are ongoing; however, this is associated with ovarian dysfunction, and should this be used with caution in girls. Radiation therapy should be avoided in children due to long-term side effects. The role of local therapy with other modalities, such as cryotherapy, is not well defined but could be discussed in small progressive lesion and/or refractory disease after several lines of therapy.

Conclusions: A Delphi process resulted in treatment recommendations for pediatric patients with desmoid tumors.

Significance: There was consensus around a shift away from surgery and toward active surveillance as a first-line treatment for pediatric desmoid tumors.

*Indicates a presentation in which the Food and Drug Administration (FDA) has not cleared the drug and/or medical device for the use described (i.e. the drug or medical device is being discussed for an “off label” use.)

OP-69

Retrospective analysis and characterization of avascular necrosis in pediatric leukemia/lymphoma patients using BLAST classification

Amin Alayleh, Hiba Naz, Vanessa Taylor, Taylor Renee Johnson, Saima Farook, Grady Harrison Hofmann, Chiamaka Nneka Obilo, Katie Harbacheck, Tara Anne Laureano, Stephanie M. Smith, Karen Chao, Stuart B. Goodman, Kevin G. Shea

Stanford University, Palo Alto, CA, USA

LOE-Prognostic-Level III

Purpose: Avascular necrosis (AVN) is a serious complication of high-dose corticosteroid therapy for pediatric patients with leukemia/lymphoma. AVN primarily affects weight-bearing joints and long bones and may lead to significant osteoarthritis and early joint replacement. Early identification and intervention for AVN may prevent progressive joint collapse. The purpose of this study is to evaluate and characterize the occurrence and location of AVN using the newly developed Bone Location for AVN from STeroids (BLAST) classification system that considers specific bone locations and its impact on future joint collapse.

Methods: An imaging database was queried for patients 25 years of age and younger with a diagnosis of AVN and leukemia/lymphoma who required corticosteroid treatment. Magnetic resonance imaging (MRI) of the patients were reviewed and AVN sites classified using the BLAST system. AVN locations were described using descriptive statistics. Multivariable logistic regression analysis was used to assess odds of AVN bilaterality based on location.

Results: A total of 84 patients (49/35 males/females) with acute lymphoblastic leukemia (B-cell 74%, T-cell 21%) or acute myeloid leukemia (5%) were included in this cohort. The median age was 14.8 years at leukemia diagnosis and 16.5 years at AVN diagnosis. The majority of AVN locations include femur (87%), tibia (68%), and humerus (25%). Based on the Stanford-BLAST classification system, the most common sites of AVN overall include the proximal tibial metaphysis (61%), distal femoral metaphysis (60%) and epiphysis (60%), and femoral head epiphysis (50%). The most common sites of AVN in the tibia, humerus, and femur are proximal tibial metaphysis (89%), humeral head epiphysis (86%), and distal femoral metaphysis and epiphysis (68%), respectively. Patients with AVN in their tibia and humerus are 7.22 times and 9.11 times more likely to develop AVN bilaterally (p = 0.002) than patients with AVN elsewhere. Epiphyseal location was considered high risk for subsequent joint collapse in all locations.

Conclusions: This retrospective analysis demonstrates that AVN in leukemia/lymphoma patients on corticosteroid therapy has a clear predilection for specific locations in long bones. Using the BLAST classification system, practitioners are better equipped to characterize the incidence and location of AVN, monitor high-risk locations for joint collapse, and track early outcomes of preventive treatment.

Significance: A standardized classification system for AVN that identifies high-risk locations for joint collapse will facilitate timely intervention for joint preservation in this population. Development of screening protocols for early detection and prospective multi-center AVN study groups will be critical to improve functional outcomes for leukemia/lymphoma survivors.

EPOS/POSNA Abstract Book (37)

OP-70

Survival of telescoping rods decreases with successive surgeries in patients with osteogenesis imperfecta

Cynthia Nguyen, Chris Makarewich, Selina Poon, Robert Hyun Cho, Theresa A. Hennessey

Shriners for Children Medical Center, Pasadena, CA, USA

LOE-Therapeutic-Level IV

Purpose: Intramedullary rodding of lower extremity long bones in patients with osteogenesis imperfecta (OI) is a widely accepted technique for fracture treatment and prevention. Previous smaller studies have shown that telescoping rods have longer survival times compared to static rods. However, there are concerns about telescopic rod performance with potential complications such as failure to lengthen, rod tip migration, and breakage requiring revision. The purpose of this study was to examine risk factors that affect rod survival length in a large cohort of patients with OI.

Methods: This was a multi-center retrospective comparative study of patients with OI who underwent intramedullary nailing of the femur and/or tibia. Each bone included had 2-year minimum follow-up from initial implantation, no rod replacement surgeries outside of the primary hospital system, and had full survival history of each rod implanted available (followed until removal or replacement). Patient demographics, clinical data, and details of each procedure were obtained. Multivariate regression analysis was used to examine risk factors for rod survival.

Results: In total, 597 rod surgeries in 171 patients met the inclusion criteria. Average patient follow-up was 10.3 (range, 2.1–18.3) years. There were 405 static rods and 190 telescoping rods. Overall, telescoping nails had longer survival times compared to solid rods (p < 0.01). Within each rod type, the number of previous rod surgeries had a significant effect on longevity for telescoping rods (p = 0.04) but not for static nails (p = 0.9), with increasing number of surgeries leading to a decrease in rod survival. The type of bone (tibia versus femur) was significant for static nails (p = 0.04) but not for telescoping nails (p = 0.13), with femur rods being a risk factor for decreasing survival. The surgeon, number of osteotomies, and the use of bisphosphonates did not have a significant effect on survival for either group. Figure 1 shows the average rod survival time versus number of previous rod surgeries per bone for telescoping and static nails.

Conclusions: For telescoping rods, the higher the number of previous surgeries, the shorter the survival time of the rod. After three rod surgeries in a bone, average survival of a telescoping rod was no longer than a static rod. For static nails, tibia nails had a longer survival than femur nails.

Significance: Surgeons should be aware that although telescoping rods do have longer survival compared to static rods, these advantages may decrease with increasing number of rod surgeries in the same bone.

EPOS/POSNA Abstract Book (38)

OP-71

Augmentation of submuscular plates in addition to telescopic rodding in the management of long bone fractures in patients with osteogenesis imperfecta

Baris Gorgun, Onur Oto, Sema Ertan Birsel, Ozan Ali Erdal, Muharrem Inan

Ortopediatri Istanbul, Academy of Pediatric Orthopedics, Istanbul, Turkey

LOE-Therapeutic-Level III

Purpose: The use of telescopic nails is a frequently used treatment method in the treatment of osteogenesis imperfecta (OI). However, providing rotational stability in telescopic nail systems is not always possible. In this respect, we believe that a long plate used in addition to the telescopic nail may be an ideal solution for this problem. Submuscular plates not only provide rotational stability but also protect the integrity of the long bones by providing additional stability and decreasing the rate of metaphyseal fractures. Our aim is to analyze the results and characteristics of the patients diagnosed with OI and underwent deformity correction surgery of the lower extremities with submuscular plates and telescopic nails simultaneously.

Methods: The study included 48 OI patients who were operated between 2019 and 2022. The deformities were in the femur, tibia, or both. In the surgical procedure, the deformity was corrected by one or two osteotomies. After that, a telescopic nail was inserted anterogradely, retrogradely, or retropatellarly. Afterward, a submuscular bridging plate was applied through the metaphyseal parts of the bone. At least six cortices were fixated at both ends of the plate. Patients were splinted for 1 week postoperatively. Partial weight-bearing was provided at the postoperative third week with thermoplastic braces. At the end of the 6 weeks, full weight was allowed. Complication and refracture rates were recorded after the surgery.

Results: In this retrospective study, patients with OI and long bone fractures of the lower extremities with a follow-up period of at least 12 months were included. In total, 48 OI patients (mean age = 8.7) and 73 bones were included in the study. The average follow-up time is 26 months (12–36 months). In all patients, the bony union was achieved without pseudoarthrosis and infections. There was a significant decrease in the rates of nail bending and fracture in patients with submuscular plate. It was also found that the immobilization period was shortened due to additional stabilization and load bearing was started earlier.

Conclusions: Telescopic nailing is an optimal surgical method in the treatment of long bone fractures in patients of OI. To decrease the fracture rates and the need for revision surgery, submuscular plates may be added simultaneously during the surgery to provide rotational stability. Further research is needed to provide clear evidence for this hypothesis.

Significance: Based on the results, a long plate used in addition to the telescopic nail could be an ideal solution for providing rotational stability.

EPOS/POSNA Abstract Book (39)

OP-72

Long-term outcomes of intramedullary nails in osteogenesis imperfecta: fewer surgeries and longer survival times with telescoping rods in patients with over 10-year follow-up

Cynthia Nguyen, Chris Makarewich, Selina Poon, Robert Hyun Cho, Theresa A. Hennessey

Shriners for Children Medical Center, Pasadena, CA, USA

LOE-Therapeutic-Level IV

Purpose: Intramedullary rodding of lower extremity long bones in patients with osteogenesis imperfecta (OI) is a widely accepted technique for fracture treatment and prevention. Previous small studies with short- to medium-term follow-up have shown that telescoping rods have longer survival times compared to static rods. However, there are no long-term studies (10 or more years) evaluating the results of these procedures. The purpose of this study was to compare the rod survival duration and number of procedures in patients treated with static versus telescoping rods with 10-year minimum follow-up.

Methods: This was a multi-center retrospective comparative study of patients with a diagnosis of OI who had intramedullary nailing of the femur and/or tibia. Each bone included in the study had 10-year minimum follow-up, only one type of rod utilized over the follow-up period, and no rod replacement surgeries outside the primary hospital system. Patient demographics, clinical data, and details of each procedure were obtained. Bones treated with static rods were compared to those treated with telescoping rods using independent-samples t-test for continuous variables and chi-square test for categorical variables.

Results: In total, 119 bones in 52 patients met the inclusion criteria. Average follow-up was 13.1 (range, 10.2–18.4) years. Average age at implantation of first rod was 4.5 years for static rods and 4.2 years for telescopic rods. There were 69 femurs and 50 tibias. There were no differences between groups in follow-up length, Sillence type, bisphosphonate use, or age at first rod placement. There were significantly more tibias treated in the static rod group compared to the telescopic rod group. Average survival length was significantly longer for telescopic rods (Table 1). Bones treated with telescopic rods had significantly fewer surgeries compared to static rods (Table 1).

Conclusions: At 10-year minimum follow-up, bone segments that received telescoping rods as the initial treatment required significantly fewer surgeries than those treated with static nails. The average survival time of telescopic rods was significantly higher.

Significance: Over the long term, bone segments in patients with OI treated with telescopic rods required fewer surgeries and had longer implant survival times compared to those treated with static rods. When available, surgeons should consider telescopic rods as the initial implant choice in this patient population.

EPOS/POSNA Abstract Book (40)

OP-73

Prophylactic intramedullary rodding following femoral lengthening in patients with achondroplasia and hypochondroplasia

Cesar G. Fontecha, Pilar Rovira Martí

Sant Joan de Déu Children Hospital Barcelona, Esplugues de Llobregat (Barcelona), Spain

LOE-Therapeutic-Level III

Purpose: Femoral fracture after femoral lengthening in patients with achondroplasia and hypochondroplasia is a frequent complication, occurring in up to 30%. The purpose of this study is to demonstrate the effectiveness of prophylactic intramedullary rodding in preventing this complication.

Methods: Multicenter retrospective study involving 86 femoral lengthening procedures in 43 patients with achondroplasia or hypochondroplasia. Forty-two femora (21 patients) were prophylactically managed with intramedullary Rush rodding following external fixation removal (11 females and 10 males, mean age 14.53 years) compared with 44 femora (22 patients) without prophylactic intramedullary rodding (13 females and 9 males, mean age 15.14 years). The mean amount of lengthening in the rodding group was 13.3 cm (52.6%), with an External Fixation Index of 25.79 days/cm; inpatients without rodding was 14.32 cm (61.5%) and 24.46 days/cm, respectively.

Results: Seven cases (15.9%) without rodding developed fracture. Four of them required surgical correction due to displacement or shortening. Only one patient (2.38%) had fracture of the femur after prophylactic rodding and surgery was not required. The incidence of femur fracture was significantly lower in the prophylactic rodding group compared to the non-rodding group (2.38% versus 15.9%, respectively; p = 0.034). There were no cases of infection or avascular necrosis.

Conclusions: Prophylactic intramedullary rodding is a safe and effective method for preventing femoral fractures following femoral lengthening in patient with achondroplasia or hypochondroplasia.

Significance: Level III—a retrospective comparative study. Mandatory treatment after femur lengthening when removing the external fixator.

OP-74

Spinal surgery in achondroplasia: causes of reoperation and reduction of risks

Arun R. Hariharan, Hans K. Nugraha, Aaron Huser, David S. Feldman

Paley Orthopedic & Spine Institute, West Palm Beach, FL, USA

LOE-Therapeutic-Level IV

Purpose: Children with achondroplasia are prone to developing symptomatic spinal stenosis requiring surgery. Revision rates are thought to be high; however, the causes and rates of re-operation are unknown. The primary aim of this study was to investigate the causes that necessitate re-operation. In addition, we report on surgical techniques aimed at reducing the risks of these re-operations.

Methods: Retrospective review over an 8-year period of all patients with achondroplasia at a single institution. Demographics and surgical/revision details were recorded. Type of surgery was placed into four categories: decompression only, decompression with a short fusion (T10), decompression with a midlevel fusion (T7–T9), and decompression with a long fusion (T2–T4). The use of interbody cage was documented. Descriptive statistics and Fisher’s exact test were performed.

Results: A total of 148 patients were identified, 33 underwent spinal surgery (22.2%) at a mean age of 17.6 years. Twenty-one patients were included, 12 were excluded for follow-up. Sixteen revisions were performed on 9 patients (43%) and 4 required multiple revisions. Fourteen (67%) primary surgeries were done at our institution and 4 (29%) required revision. On average, the time from initial surgery to revision was 1.9 years. Some revision surgeries were performed for multiple reasons: 8 pseudarthroses, 7 proximal junctional kyphosis (PJK), and 7 new neurologic findings. The mean follow-up from the index procedure was 5.8 years. Short fusions were more likely to develop PJK with an odds ratio (OR) of 31.2 (p = 0.007). Short fusions without a caudal interbody were also more likely to develop a caudal pseudarthrosis when compared with long and mid-fusions without a caudal interbody (p = 0.044). To date, none of the initial long fusions with interbody have required revision.

Conclusions: This is the largest study of re-operative spinal deformity in patients with achondroplasia. The rate of surgery is 21.5% and the risk of revision is 32.1%. This is primarily due to pseudarthrosis, PJK, and recurrent neurologic symptoms. Surgeons should consider discussing spinal surgery as part of the patient’s life plan and should consider wide decompression of the stenotic levels and fusion from T4 with the use of interbody cage at the caudal level in all patients to reduce risks of revision.

Significance: Children with achondroplasia have a high risk of developing symptomatic spinal stenosis requiring surgery. Revision rates of surgery are high and are most often due to pseudarthrosis and PJK. Longer fusions and use of an interbody cage can help mitigate these risks.

EPOS/POSNA Abstract Book (41)

OP-75

Collagen-type 2 skeletal dysplasias: key clinical, radiographic, and MRI findings guide cervical stabilization decision-making

Bryan Menapace, Colleen P. Ditro, Kenneth Rogers, Jeffrey Campbell, William G. Mackenzie, Stuart Mackenzie

A.I. duPont/Nemours Children’s Hospital, Wilmington, DE, USA

LOE-Economic-Level IV

Purpose: Cervical spine (CS) pathology is frequently encountered in pediatric skeletal dysplasias (SD). Collagen type 2 (COL2) patients are at risk for pathologic atlantoaxial instability (AAI). The value of associated clinical and imaging findings has yet to be compared. This study assesses these modalities and identifies significant values for surgical decision-making.

Methods: An institutional review board (IRB)-approved retrospective case series via Epic query (2007–2023) for SD with CS imaging. Inclusion criteria: COL2 diagnosis, pediatric orthopedist’s history and examination, CS flexion and extension (F:E) radiographs, and CS F:E magnetic resonance imaging (MRI). Patient demographics and clinical findings were collected. Radiographic measurements included dens diameter, anterior atlanto-dens interval (AADI), and posterior ADI (PADI). MRI measurements included cord diameter, space available for the cord (SAC), and myelomalacia. Surgical records were reviewed. Statistical analysis involved t-tests, significance p ≤ 0.05.

Results: In total, 547 SD patients with CS imaging included 78 COL2 patients. Fifty-one of 78 met all inclusion criteria. Patients included five COL2 diagnoses, most commonly spondyloepiphyseal dysplasia (64.7%, 33). Patients were majority 53.9% female (n = 27) and 80.4% White (n = 41). 17.6% underwent surgery (n = 9). Clinically, ≥1 AAI symptom was documented in 33.3% (3/9) of surgical and 19.0% (8/42) of nonsurgical patients (p = 0.18). Physical examination revealed ≥1 upper motor neuron sign(s) in 55.5% (5/9) of surgical and 23.8% (10/42) of nonsurgical patients (p = 0.030). Surgical versus nonsurgical comparison found radiographic dens diameter as a percentage of C1 (51.3 versus 39.3%, p < 0.0001), change in AADI F:E (6.46 versus 3.26 mm, p = 0.004), and change in PADI F:E (−7.23 versus −2.90 mm, p < 0.0001). MRI findings included SAC at neutral position (7.4 versus 9.2 mm, p = 0.016), change in SAC F:E in mm (1.9 mm versus 0.6, p = 0.002) and relative to cord diameter (31.1% versus 8.2%, p = 0.0008), and incidence of myelomalacia (77.8% versus 16.7%, p < 0.0001). Surgical management included 77.8% (7) C1 decompression with immediate (6) or delayed (1) occipital-cervical fusion. Two patients (22.2%) underwent C1-2 fusion.

Conclusions: Clinical history did not provide a significant association, while the presence of a myelopathic examination did. Since both COL2 cohorts demonstrated AAI on imaging, the key value is identifying appropriate surgical thresholds. The most valuable measures include F:E PADI, change in MRI SAC F:E relative to cord diameter, and myelomalacia.

Significance: This study, the largest case series on COL2 conditions, shows the value of various clinical and radiology studies in the management of COL2 AAI, and it provides insight into the critical measurements that can aid surgical decision-making.

EPOS/POSNA Abstract Book (42)

OP-76

Screening and early management of hips in children with spina bifida following prenatal surgical closure

Domenic Grisch, Aurelia Hof, Britta Krautwurst, Thomas Dreher

University Children’s Hospital Zurich, Zurich, Switzerland

LOE-Prognostic-Level II

Purpose: Spina bifida (SB) patients are more likely to suffer from hip dysplasia and developmental delays. At the Children’s Hospital Zurich, a study to assess the prevalence of hip dysplasia in a group of SB patients with fetal closure of the spinal lesion was conducted and described this population’s characteristics.

Methods: Hip ultrasound images of 144 children with SB following fetal SB repair surgery who underwent the examination during their first 6 months of life were analyzed. The sonographic angle measurements were classified into hip maturity types according to the Graf method, divided into five types. Descriptive statistics were applied to summarize and present the data collected during the assessment of hip dysplasia prevalence in the group of SB patients following prenatal spinal closure.

Results: The prevalence hip dysplasia in this SB patient group was 3.8%, which was in the middle of the range reported in the general population (0.24%–7.15%) and did not reach the expected percentages (30%–50%) of previous SB studies. Eleven percent of immature hips were found, and in the subpopulation, 90% matured within 6 months.

Conclusions: This study may prove that fetal SB repair also benefits hip development. However, future studies with larger patient groups and control sonographies are needed to provide more significant statements and determine the long-term outcomes of SB patients with hip dysplasia who have undergone fetal surgery.

Significance: SB patients are more likely to suffer from hip dysplasia and developmental delays. Overall, these notable findings, that there may not be a significant difference in hip dysplasia rates between fetal-operated SB children and the general population, represent a significant contribution to the field, providing a solid foundation for further research on this topic. As this study is one of the first to examine the hip development of fetal-operated SB patients, the pleasing results further highlight the importance of studying hip development in children with SB and emphasize the need for continued investigation.

OP-77

Does open reduction of arthrogrypotic hips cause stiffness?

Harold J.P. Van Bosse, David Teytelbaum, Solomon Samuel, Vinieth Bijanki, Stephen Silva

St. Louis University, St. Louis, MO, USA

LOE-Therapeutic-Level IV

Purpose: Congenital hip dislocation in arthrogryposis multiplex congenita (AMC) occurs in 15%–30% of patients. Although open reduction yields positive outcomes, concerns about potential iatrogenic hip stiffness persist. Our study compares pre- and postoperative hip ranges of motion (ROMs) and assesses ambulatory abilities in patients after open reduction. We hypothesize that the pre-existing motion limitations are minimally affected by relocation.

Methods: From 2008 to 2018, 52 consecutive patients with AMC underwent 75 open reductions of congenitally dislocated hips (23 bilateral), most via a medial approach with femoral shortenings osteotomies as needed. All had ≥2-year follow-up. Hip ROM was recorded preoperatively, post-operatively, and at last follow-up, as was ambulatory ability. Simultaneous and subsequent hip operations were recorded.

Results: Average age at surgery was 23 months (range, 10–58 months), with 68-month (24–152 months) follow-up. Thirty-four hips had flexion contractures >20° preoperatively (average 33°), improving by 22° at follow-up; 61 hips had <45° frog leg abduction (average 27°), improving by 11°; 41 hips had <30° abduction preoperatively (average 20°) which improved by 11°, all p-values < 0.001 (Table 1). Hips that had <90° of flexion pre-operatively showed no improvement or worsening at follow-up (p = 0.867). Flexion-extension (Flx-Ext) total arc of motion (TAM) for all hips decreased by only 2° from pre-operative to follow-up (p = 0.507), and the internal-external rotational (IR-ER) TAM in extension decreased 13° (p < 0.001). Pre-operatively, the 29 unilateral dislocated hips had an average TAM flx-ext of 7° less than the contralateral hip (85° versus 92°); at final follow-up, that discrepancy only increased 3° (78° versus 88°). All other TAMs were statistically unchanged at follow-up. Of the 52 patients, 30 were independently ambulatory at follow-up, most with braces, while 16 were walker-dependent but still progressing; six remained non-ambulatory.

Conclusions: Open reduction for arthrogrypotic hip dislocations maintains mobility without causing stiffness. While pre-existing hip motion limitations slightly worsened, lower limb positioning improved, enhancing ambulation—especially in hip extension and abduction. Most achieved independent ambulation.

Significance: The results of this study challenge the prevailing belief that performing an open reduction on arthrogrypotic hips leads to significant functional stiffness. Our findings suggest that open reduction can offer the patient a more functional hip, contrary to the perception of limited mobility. Children with AMC often have ambulatory potential if their limb positioning can be optimized.

EPOS/POSNA Abstract Book (43)

OP-78

Burosomab reduces the need for hemiepiphysiodesis in hypophosphatemic rickets

Christopher James Marusza, Zakir Haider, Kelvin Miu, Daniel Thomas Fontannaz, Deborah Eastwood

Great Ormond Street Hospital, London, UK

LOE-Therapeutic-Level III

Purpose: X-linked hypophosphatemic (XLH) rickets is the commonest inherited form of rickets. Children often present with lower limb deformities. Corrective osteotomies in early childhood are associated with high recurrence rates and the risks of surgery. Burosumab is a monoclonal antibody approved in 2018 for the treatment of XLH. Administered fortnightly by subcutaneous injection, it is now the preferred medical treatment. We report the use of hemi-epiphysiodesis in a cohort of XLH patients pre and post the introduction of Burosumab.

Methods: XLH patients referred to our orthopedic unit since 2005 were reviewed. Hemi-epiphysiodesis was undertaken if there was progressive mechanical axis deviation after 1 year of maximized medical treatment. The rate of correction of deformity per month (RoC) was calculated from standardized long-leg radiographs using Traumacad software. Statistical analysis was performed using SPSS. The Mann–Whitney U test was used for analysis of continuous data. Statistical significance was set at p < 0.05.

Results: Since 2005, 28 patients were seen for orthopedic assessment. Sixteen patients required 18 episodes of guided growth (32 limbs, 40 segments). Mean age was 10.2 (4.3–14.7) years. Neutral mechanical axis was restored in 13/32 (41%) limbs: a further 7 (22%) improved. Mean follow-up was 42.7 (6–116) months. Three patients (four limbs) underwent an osteotomy. The mean RoC with hemi-epiphysiodesis was 0.35° for the distal femur and 0.20° for the proximal tibia. Diaphyseal deformity RoC was 0.12° per month in both the femur and the tibia. Younger patients (≥3 years of growth remaining) corrected at the same rate as older patients. The RoC was higher for the distal femoral deformity and the femoral diaphyseal bow in females (p = 0.043 and 0.047, respectively). Since 2018, 28 patients commenced Burosumab treatment, mean age 7.8 (0.5–14.5) years. Mean follow-up was 31 (5–53) months. The mean RoC per month with Burosumab was 0.21° for the distal femur and 0.15° for the proximal tibia, and 0.18° for both femoral and tibial diaphyseal deformity. No statistical significance was found in RoC between hemi-epiphysiodesis and Burosomab treatment. No patient treated with Burosumab has required hemi-epiphysiodesis.

Conclusions: The data confirm that, in conjunction with medical therapy, hemi-epiphysiodesis is effective in correcting lower limb deformity. Burosumab alone demonstrates a similar improvement and no hemi-epiphysiodesis has yet been required.

Significance: This study suggests that Burosomab treatment of XLH improves lower limb deformity and reduces the need for hemi-epiphysiodesis.

OP-79

Ethnicity is a risk factor for permanent brachial plexus birth injury

Petra Grahn, Aarno Yrjana Nietosvaara, Mika Gissler, Marja Kaijomaa

Helsinki University Hospital, New Children’s Hospital, Helsinki, Finland

LOE-Prognostic-Level II

Purpose: We aimed to assess the incidence and risk factors related to permanent brachial plexus birth injury (BPBI) in Southern Finland.

Methods: Helsinki University Hospital (HUS) New Children’s Hospital is the primary and only care center for BPBI in Southern Finland, while HUS Women’s Hospital oversees and trains all birth units in the region which hosts a population of 1.7 million. Birth information of all mothers and their children born 2006–2022 were gathered from the national database and compared to prospectively gathered data from mothers and children with a permanent BPBI. Permanent injury was defined as limited active or passive ROM or decreased strength of the affected limb detected at 1 year of age. Severity of the injury was assessed using the 3-month Toronto test score. In Finland, all women are subjected to the same prenatal care, and no private delivery hospitals exist.

Results: A total of 298,428 children were born within the study period. Six hundred acquired a BPBI, 100 of which were permanent. The incidence of permanent BPBI was 0.4 per 1000 vagin*l live births (0.34 all births) with a declining trend. Children to immigrant mothers, and women of Black ethnicity had a higher incidence of a permanent injury (0.85 and 1.52). Non-White background and immigrant status correlated with a more severe injury (β = −1.12 range, −2.17 to −0.07, p = 0.004) with children of Black mothers having the least favorable outcome (β = −1.64 range, −2.79 to −0.49, p = 0.005). In the multivariate regression model, gestational diabetes in a Black mother further strengthened the negative effect (β = −0.99, range, −1.98 to −0.00, p = 0.049).

Conclusions: The overall incidence for a permanent BPBI is on a decline. However, care needs to be taken especially in non-White women to prevent and in a timely manner recognize and treat risk factors leading to severe birth complications.

Significance: Black ethnicity and immigrant status are risk factors for a permanent and more severe BPBI.

EPOS/POSNA Abstract Book (44)

OP-80

Sprengel deformity: what is the functional outcome and quality of life after surgery according to the EQ-5D-Y and the short version of Disabilites of the Arm, Shoulder, and Hand Questionnaire (quickDASH)?

Carina Antfang, Adrien Frommer, Georg Gosheger, Robert Roedl, Andrea Marira Laufer, Gregor Toporowski, Henning Tretow, Jan Duedal Rölfing, Bjoern Vogt

Department of Pediatric Orthopedics, Deformity correction and Foot surgery, University Hospital, Muenster, Germany

LOE-Therapeutic-Level IV

Purpose: Sprengel deformity is a rare skeletal deformity due to a maldescent of the scapula. In addition to cosmetic issues, abduction limitation of the affected shoulder can be functionally impairing and thus the primary indication for surgical treatment. This study is designed to evaluate the function of the shoulder of patients who underwent surgery for deformity correction and those treated conservatively.

Methods: The longitudinally maintained database of our orthopedic teaching hospital was retrospectively analyzed to identify all patients with Sprengel deformity who were treated from 2016 to 2022. Nineteen patients with a mean age of 6 years (min./max. 0/16 y), with 21 affected shoulders (right = 10; left = 7; bilateral = 2) were included. Of these, 8/19 patients with a median Cavendish 4/Rigault 3 score and severe functional impairment were treated surgically according to a modified Green procedure and 11/19 patients (Cavendish 2/Rigault 2) were treated conservatively by means of physiotherapy. Shoulder function was assessed by clinical examination and the short version of Disabilities of the Arm, Shoulder, and Hand Questionnaire (quickDASH). Quality of life was evaluated using the EQ-5D-Y.

Results: In the surgical group, the Cavendish 4 could be reduced to Cavendish 1 (min./max. 1/3). Shoulder abduction improved by 45° (interquartile range, 27.5) to a postoperative abduction of 135° (median conservative cohort: 105°). Five of those eight patients were satisfied with the outcome, one unsure and one unsatisfied. On average, patients needed 3 months to be able to return to daily life activity. Nine of 19 questionnaires were complete. The median quickDASH score was 23 in the surgical cohort and 9 in the conservative cohort. Average follow-up was 66 months (min./max. 4/145). The quality of life according to the EQ-5D-Y was 72/100 in the surgical cohort and 77/100 in the conservative group.

Conclusions: Although surgical intervention in Sprengel deformity implies intense surgery, it can improve the abduction of the affected shoulder and may reduce disability in daily life at a moderate level. Yet, mild forms can still have a sufficient function and should therefore not be considered for surgery. Quality of life seems to be almost equal in both groups. Thus, when advising about performing surgery on patients with Sprengel deformity, the quickDASH can help to evaluate the current limb function and lead together with the clinical evaluation to a better decision making.

Significance: Sprengel deformity is a rare congenital disorder and surgical correction means high impact surgery. It is therefore important for clinicians to know the gain by surgery for better patient counseling.

OP-81

Medium- and long-term clinical and functional outcomes of modified Green’s procedure for Sprengel shoulder in children

Giovanni Trisolino, Marco Todisco, Paola Zarantonello, Giovanni Di Gennaro, Alessandro Depaoli, Gino Rocca

IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy

LOE-Therapeutic-Level IV

Purpose: Sprengel shoulder is a rare congenital deformity caused by failure in the descent of the scapula during early fetal growth. This condition leads to hypoplastic, elevated, and malrotated scapula. The present study described clinical and functional outcomes in pediatric patients treated with surgery for Sprengel shoulder.

Methods: From June 2010 to April 2021, 32 scapulae in 31 pediatric patients were surgically treated at our institution. Cavendish classification for aesthetics and Rigault classification for radiological appearance were used to assess deformity. Abduction and elevation movements were quantified. The following patient-reported outcome measures (PROMs) were administered: QuickDASH, Simple Shoulder Test (SST), the Shoulder Pain Index and Shoulder Disability Index (SPADI), and UCLA Shoulder Scale. Complications were evaluated according to the modified Clavien–Dindo–Sink classification. Clavicle osteotomy and omovertebral bone resection were also performed in some cases.

Results: With a mean follow-up of 6.4 years (range, 1–11.2 years), 2/32 major complications were found. In 18/32 patients, a Cavendish value of 1 was found, 18/32 achieved a degree of abduction greater than 120°, and 21/32 achieved a degree of elevation greater than 135°. The scores indicate that a good functional and aesthetic result was achieved in most cases. Few studies have used validated scores, often after treatment with Woodward technique. Moreover, this case series represents the largest collection of SD patients treated surgically.

Conclusions: In our experience, the modified Green’s technique proved to be a safe procedure with a low rate of complications and recurrences. Despite the prolonged follow-up, we believe that the functional results should be evaluated even after the full maturation of the musculoskeletal system to confirm the long-term efficacy of this treatment.

Significance: This case series confirmed the good results of the modified Green’s procedure in one of the largest cohort of patients ever reported.

OP-82

Osteot-OH MY! contemporary surgical techniques may reduce revision rates following preaxial polydactyly reconstruction

Eliza Buttrick, Sarah L. Struble, Shaun Mendenhall, Benjamin Chang, Sulagna Sarkar, Apurva S. Shah

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Therapeutic-Level IV

Purpose: Previous investigations into preaxial polydactyly reconstruction established revision surgery rates ranging from 7% to 19%. This study aimed to define the rate and type of post-operative complications following surgical treatment of preaxial polydactyly.

Methods: Demographics, modified Wassel-Flatt classification, and surgical and post-operative data were abstracted from the electronic medical records of patients with preaxial polydactyly at a single children’s hospital between 2011 and 2022. Patients were contacted to complete an aesthetic survey adapted from the Australian Hand Difference Register, Wong-Baker pain, and PROMIS Upper Extremity Function and Peer Relations modules. Data were analyzed via descriptive statistics and non-parametric tests.

Results: A total of 232 children with 248 cases of preaxial polydactyly (6.5% bilateral, 43.5% female) underwent surgical treatment at a mean age of 1.5 ± 1.4 years, with a mean 1.3 ± 2.0 years of follow-up. Patients mostly presented with Wassel-Flatt type IV duplications (87 thumbs, 35.1%), and notably, an additional 31 (12.5%) were the hypoplastic subtype. The majority of cases (181/248, 73.0%) underwent resection with reconstruction at a mean age of 1.6 ± 1.5 years, with reconstruction including elements of ligament reconstruction, corrective osteotomy (n = 97, 53.4%), and/or tendon realignment. Early post-operative complications occurred in 23/248 (9.3%) patients. Long-term complications occurred in 87/249 cases (34.9%), significantly more likely in triphalangeal thumbs and in cases needing reconstructive surgery (p < 0.001, Table 1). Only nine patients underwent revision surgery, all requiring corrective osteotomy for coronal plane deformity (mean pre-revision IPJ angular deformity 29.7° and mean MPJ angular deformity 20.0°). Thirty-nine patients completed prospective questionnaires at an average age of 7.3 ± 3.5 years, with normal PROMIS UE and Peer Relations scores (mean 46.4 ± 9.2 and 52.4 ± 9.2, respectively). Nearly all (31/37) respondents reported negligible pain (0–1). Regarding aesthetics, 27 patients (69.2%) reported they “strongly agreed” or “agreed” with the statement “I am happy with how my hands look.” Similarly, 35 respondents (89.7%) “strongly agreed” or “agreed” that their operation(s) made their hands look better.

Conclusions: The revision surgery rate was 3.6%, reflecting technical emphasis on corrective osteotomy, ligament reconstruction, and/or tendon realignment at index surgery. In fact, more than half of the cases were treated with osteotomy at the time of the initial procedure. Normal post-operative function and excellent cosmesis can be expected.

Significance: Our series demonstrated a lower rate of revision surgery than previously reported in children with preaxial polydactyly, indicating the importance of corrective osteotomy at index surgery.

EPOS/POSNA Abstract Book (45)

OP-83

Surgical versus nonsurgical management of pediatric ganglia—a cost and outcomes analysis

Bryce Bell, Umar Ghilzai, Zuhair Jameel Mohammed, Christine Yin, Abdullah Ghali, Qianzi Zhang

Baylor College of Medicine, Houston, TX, USA

LOE-Therapeutic-Level III

Purpose: Pediatric ganglia are an understudied phenomenon, with an estimated 10% of all ganglia occurring in pediatric patients. Data on treatment modalities, recurrence rates, and cost effectiveness remains sparse. This study aims to characterize recurrence rates of surgical versus conservative management of pediatric ganglia, along with cost-effectiveness analysis of treatment modalities.

Methods: This was a retrospective cohort study that included all patients from 1 December 2011 to 15 March 2023 that were treated at a single institution for primary or recurrent ganglia of the wrist. Patient data was gathered regarding ICD-10 code, CPT code, date of procedure, primary payer, and total cost of procedure associated. These data were then stratified into two cohorts: surgery and percutaneous ultrasound-guided fenestration of ganglia (PUGG). Patient data was analyzed for rates of recurrence, treatment methods for recurrence, and total costs of treatment.

Results: Five hundred and ninety-five patients comprised our cohort, with a total of 710 procedures performed—296 underwent PUGG and 414 underwent surgery. We noted a recurrence rate of 14.7% after PUGG and 21.2% after surgery. Mean time to recurrence was 302.66 days after the PUGG cohort and 1619.13 days after surgery (p < 0.0001). PUGG recurrence was treated with surgery in 76.3% of cases and surgery recurrence was treated with re-operation in 59.2% of cases. Average payer charge was $2224.01 for PUGG and $11,645.71 for surgery (p < 0.0001). Significant differences were seen in charges among private insurers (BCBS, p < 0.0001) and Medicaid/CHIP (p = 0.0004). No significant differences were seen in cost of re-operation and repeat procedure for both surgery and PUGG groups, respectively, even after controlling for insurer status.

Conclusions: Ganglia are a challenging entity to definitively treat. PUGG can present as an alternative option for pediatric ganglia given its cost-effectiveness and comparable recurrence rates. One factor for practitioners to note is the faster time to recurrence for PUGG-treated ganglia. Both cohorts saw a preference for recurrence treatment with surgical management. Overall, PUGG can serve as an effective management strategy for pediatric ganglia.

Significance: This study is one of a few to examine pediatric ganglia recurrence rates after surgery and PUGG along with associated costs. This study shows that PUGG can effectively manage pediatric ganglia, with lower associated charges and recurrence rates.

OP-84

Tendon transfer in spastic cerebral palsy upper limb

Mahzad Javid, G. Hossain Shahcheraghi, Hadi Gerami

Shiraz Medical University, Shiraz, Iran

LOE-Therapeutic-Level III

Purpose: Cerebral palsy (CP) in upper limb produces functional, aesthetic, and hygienic issues and is not always amenable to surgical procedures. We are reporting a single-center, long follow-up experience with tendon transfer in wrist and forearm CP.

Methods: The CP cases who had undergone tendon transfer in hand, wrist, and forearm in a 14-year period were evaluated for change in motion, function, and cosmetic appearance and also assessed by MACS (Manual Ability Classification System) and DASH (Disability of Arm, Shoulder, Hand) scores.

Results: Forty-two spastic CP patients with a mean age of 19.81 (10–34 years, SD: 5.36) years, with a mean follow-up of 5.5 (2–14) years, entered the study. Twenty-four cases were Gross Motor Function Classification System (GMFCS) I or II and 18 were III or IV. Supination beyond neutral was seen in 48.5%, and improvement in MACS scores in all the cases. Improved “grasp” and “release” and keyboard use was seen in 50%, 71%, and 87% respectively. The satisfaction from appearance and improved function of 83%–96% correlated positively with GMFCS, MACS, and DASH scores. Noticeable improvement in personal hygienic care was seen in only 52% of cases.

Conclusions: Tendon transfer in well-selected spastic upper extremity CP cases results in long-time improved function and limb appearance—correlating with initial GMFCS and MACS scores.

Significance: A long-term results of function improvement in pure spastic CP upper limb.

OP-85

Factors influencing return of elbow motion following pinning of displaced supracondylar humeral fractures

Akbar Nawaz Syed, Pooja Nilesh Balar, Margaret Bowen, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Therapeutic-Level IV

Purpose: Various operative and post-operative protocols exist for the management of displaced supracondylar humeral fractures with most providing excellent functional outcomes by 1 year. However, factors influencing the early return of elbow motion have not been evaluated. This study aims to identify factors influencing the time to return of elbow motion following operative fixation of displaced supracondylar humeral fractures.

Methods: An institutional review board (IRB)-approved retrospective study was conducted of patients <18 years old treated at a tertiary children’s hospital from January 2013 to January 2020 for a displaced supracondylar humerus fracture (Gartland type III/IV). Time to functional elbow motion was recorded for each patient and defined as elbow extension <30 degrees and flexion >130 degrees. Patients with screw fixation, inadequate documentation, insufficient follow-up, and incomplete recovery <1 year were excluded. Demographic data, injury characteristics, operative technique, and post-operative factors were recorded. Analysis was performed using Kruskal–Wallis/Mann–Whitney U tests after ensuring normality using the Shapiro–Wilk test.

Results: A total of 433 displaced supracondylar humeral fractures were identified with an average age of 6.2 years. Patient characteristics are outlined in Table 1. Median time to recovery of elbow motion was 40 days. Flexion injuries (n = 17/433, 3.9%, p = 0.012), fractures associated with nerve injuries (n = 86/433, 19.9%, p < 0.001), fractures undergoing open reduction (n = 26/433, 6%, p = 0.012), and those fixed using >3 pins (n = 63/433, 14.5%, p = 0.018) took twice as long to regain motion. Referral to physical therapy was not beneficial for return of motion (p < 0.001). Immobilization >21 days following pin removal (<0.001) delayed the return of motion by ~4 weeks. Age, gender, additional ipsilateral fracture, days to pin removal, pin construct, and management of additional ipsilateral fracture (Op versus non-Op) did not delay the return of elbow motion (p > 0.05).

Conclusions: To our knowledge, this is the first study to describe factors influencing the return of elbow motion. Delay in return of motion is seen with flexion-type injuries, concomitant nerve injuries, fractures requiring open reduction, and >3 pins. Splinting more than 3 weeks following pin removal also delays recovery.

Significance: At-risk populations for delay in return to elbow function include flexion-type injuries or nerve injuries and those requiring open reduction or more than 3 pins for fixation. Once pins are removed, immobilization in a splint for more than three additional weeks, even if motion is permitted when the splint is removed, can delay recovery as well.

EPOS/POSNA Abstract Book (46)

OP-86

Development of a new classification for forearm involvement in patients with multiple hereditary exostosis (MHE) using the Delphi process

Carley Vuillermin, Maria F. Canizares, CoULD Study Group

Boston Children’s Hospital, Boston, MA, USA

LOE-Diagnostic-Level V

Purpose: Classification schemes of forearm deformity in multiple hereditary exostosis (MHE) were developed to guide surgical care in retrospective case series and have been shown to have low reliability in a prospective population. The purpose of this study is to develop a widely applicable classification system using the Delphi consensus technique.

Methods: Fifteen experienced pediatric orthopedic hand surgeons from the Congenital Upper Limb Registry (CoULD) Study Group undertook seven rounds of online surveys to establish consensus. Investigators (CV, MC) analyzed results and provided structured feedback between rounds, without direct contact with experts. A research associate administered expert surveys and anonymized results to investigators. Round 1 began with an open-ended questionnaire to identify the clinical features of forearm MHE experts believe may predict outcomes. Round 2 and beyond aimed to achieve consensus. Consensus agreement was defined as ≥70% responses of either “strongly agree” or “agree” for a 7-point Likert-type or “agree” in a dichotomous question.

Results: In Round 1, a total of 10 patients and radiological characteristics were identified as themes for inclusion: (1) age at diagnosis; (2) family history; (3) genetic diagnosis; (4) symptoms (pain, stiffness, activity limitations); (5) clinical exam findings (visible deformity, wrist deviation, ROM limitation); (6) location of the osteochondroma; (7) number of osteochondroma; (8) bone alignment and shortening; (9) joint alignment; and (10) progression of the deformity. Round 2 consisted of a 7-point Likert-type scale. At this round, radial head dislocation, bone segment, ulnar shortening, radial alignment, distal radial inclination, distal radio ulnar joint (DRUJ), radial shortening, and ulnar variance were the items that reached the agreement threshold. In Round 3, experts were asked to choose between 3 or 4 categorical levels for the classification. Rounds 4 and 5 proposed a mild/moderate/severe classification and asked about the placement of each characteristic. In Round 6, experts asked to classify nine radiographs with the proposed classification and indicate whether this version fully classified the deformity. Closing criteria were met in the seventh and final round with 93% agreement. The proposed classification is presented in Table 1. Response rate was 100% in all rounds, with a range between 1 and 35 days to responses.

Conclusions: The new CoULD MHE forearm classification developed by experts in the field of pediatric hand surgery incorporates three categories of forearm involvement: Type 3-Severe forearm involvement, Type 2-Moderate forearm involvement, and Type 1-Mild forearm involvement.

Significance: This work represents the first step in the validation process of a clinically applicable and inclusive classification for patients with forearm MHE.

EPOS/POSNA Abstract Book (47)

OP-87

Flippin’ out over gymnast wrist: presentation and treatment of distal radial physeal stress syndrome in young gymnasts

David Peter VanEenenaam, Scott J. Mahon, Naomi Brown, Joseph Yellin, Apurva S. Shah

The Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Not Applicable-Level IV

Purpose: Gymnast wrist is a niche injury experienced primarily by young gymnasts secondary to repetitive load bearing on the distal radius. Patients report insidious-onset wrist pain with physeal tenderness on examination and characteristic physeal widening on radiographs. Treatment typically involves prolonged immobilization, posing challenges for an otherwise highly active population. Current literature is limited when describing the overall treatment outcomes of gymnast wrist. This study aimed to understand the demographics, treatment outcomes, and return-to-sport timelines in a large patient sample.

Methods: Pediatric patients from 2016 to 2023 were identified using ICD-10 codes for “gymnast wrist” and wrist pain. Adults, acute fractures, non-gymnasts, and congenital etiologies were excluded. We collected patient data, Child Opportunity Index (COI), activity, treatment, radiographs, and outcomes. Statistical tests included chi-square, t-test, and Wilcoxon rank-sum analysis.

Results: A total of 78 wrists in 62 patients (60, 97% female) with an average age of 11.8 ± 1.7 (range, 6.9–15.4) were included. Average time to presentation was 12.2 weeks after symptom onset. All patients presented with wrist pain and tenderness over the physis, including 35.5% with symptoms on the dominant side, 38.7% on the nondominant side, and 25.8% with bilateral symptoms. The affected individuals averaged 15.9 ± 9.1 h of gymnastics participation per week. On initial wrist radiographs, 43 (69%) had distal radial physeal widening, 45 (73%) had juxtaphyseal sclerosis, and 12 (19%) had positive ulnar variance. For initial treatment, 55 (89%) were treated with splinting/rest/avoidance of weight-bearing with or without PT, 5 (8%) with short arm cast, and 2 (3%) underwent surgery. Thirty-two (53%) patients had resolved tenderness and return to sport after initial non-operative treatment. Among these 32 patients, average time to resolved tenderness was 7.4 weeks and average time to return to sport was 8.6 weeks. Approximately 23% of patients who initially improved with non-operative treatment later developed recurrent symptoms requiring a new period of rest. No significant differences were found in age, height, weight, body mass index (BMI), activity frequency, or prescribed treatment duration between patients whose symptoms resolved versus those whose symptoms persistent/recurred. Seven (11%) patients progressed to growth arrest, all of whom were eventually treated with ulnar shortening osteotomy.

Conclusions: Only about half of the patients with gymnast wrist respond well to conservative treatment. Recurrence rates are high, necessitating extended breaks from competitive athletics. More than 10% of patients progress to growth arrest requiring surgery.

Significance: Further prospective research is needed to identify risk factors for persistent or recurrent wrist pain in gymnasts.

EPOS/POSNA Abstract Book (48)

OP-88

Cerebral palsy in the British Orthopedic Surgery Surveillance Study (CPinBOSS)

Marie-Caroline Nogaro, Julie Stebbins, Daniel Christopher Perry, Tim Theologis

University of Oxford, Oxford, UK

LOE-Not Applicable-Level IV

Purpose: Musculoskeletal deformity in ambulant children with cerebral palsy (CP) is often addressed with single-event multi-level surgery (SEMLS). Despite its wide use, there is weak evidence on the effectiveness of SEMLS in improving gait and function, and variation in surgical practices and clinical indications. The aim of this study was to undertake national surveillance of current SEMLS practice in children with CP in the United Kingdom.

Methods: A national prospective cohort study of diplegic children (5–16 years) with Gross Motor Function Classification System (GMFCS) level I–III was conducted. Between April 2019 and March 2022, children who attended any hospital providing SEMLS in the United Kingdom, and who were deemed eligible to undergo SEMLS were recruited. Routine clinical data including GMFCS level, gait analysis data as summarized by the Gait Profile Score (GPS), motor function (FMS), and details of the surgical interventions were collected. Patient-reported outcome measures (PROMs) were assessed at baseline and 1 year post recruitment or surgery in a subgroup of consented participants.

Results: A total of 202 children were recruited over a 36-month period. In total, 152 children (75%) underwent surgery within the study period. The mean GMFCS, GPS, and FMS (5 m, 50 m, 500 m) scores at baseline for these children were 2.47 (0.68), 15.7 (4.8), and 4.01 (1.64), 3.09 (1.75), and 2.38 (1.76), respectively. In surgical patients, there was an overall improvement of GPS and FMS scores at 1 year (12.6 (3.9) and 4.14 (1.39), 3.50 (1.57) and 2.68 (1.84)), and the GMFCS level remained stable. Similarly, in non-surgical patients, there was no change in GMFCS level (2.56 (0.55) versus 2.71 (0.49)), but contrary to the surgical group, there was no overall improvement to GPS and FMS scores at 1 year. Of the 72 patients who completed the baseline PROM (in the consented cohort), 53% completed this at the 1-year follow-up. In surgical patients, there was overall improvement of GOAL at 1 year, but no change in the non-surgical patients.

Conclusions: The results from this national study in the United Kingdom indicate that SEMLS is effective in improving gait pattern, as measured by the GPS and patient-reported functional mobility as measured by the GOAL at 1 year from SEMLS.

Significance: This study has assessed current SEMLS practice in the United Kingdom and laid the foundation for the development of large-scale randomized trials on the management of this complex patient population.

OP-89

Health-related quality of life in ambulatory children with physical disabilities

Chris Church, Sana Patil, Stephanie Butler, Freeman Miller, Jose De Jesus Salazar-Torres, Nancy Lennon, M. Wade Shrader, Maureen Donohoe, Faithe Rassias Kalisperis, Stuart Mackenzie, L. Reid Boyce Nichols, Nemours Gait Lab

Nemours A.I. Dupont Hospital for Children, Wilmington, DE, USA

LOE-Prognostic-Level III

Purpose: Health-related quality of life (HRQOL) is defined as “perceived wellbeing in physical, mental, and social domains of health.” This study aimed to evaluate HRQOL in children with the most common physical disabilities and examine its relationship with gross motor ability.

Methods: In this institutional review board (IRB)-approved retrospective study, the parent-reported Pediatric Outcomes Data Collection Instrument (PODCI) and Section D of the Gross Motor Function Measure (GMFM-D) were administered to ambulatory children aged 2–18 with a diagnosis of cerebral palsy (CP; GMFCS II), arthrogryposis, achondroplasia, or Morquio syndrome during clinical visits to the Gait Laboratory. The PODCI assesses perceptions across six domains associated with mobility, pain, and happiness. It is validated for children (age 2–10 years) and adolescents (age 11–18 years). PODCI results were compared to published norms (TDY) using T-tests. The relationship between PODCI and GMFM-D scores was analyzed with Pearson correlations. To examine differences in HRQOL between diagnoses, pairwise comparisons of PODCI scores using the Wilcoxon rank-sum test with Bonferroni corrections was conducted.

Results: Children and adolescent groups within all four diagnoses demonstrated limited mobility and higher pain compared to TDY (p < 0.015). Happiness was lower in children and adolescents with CP, arthrogryposis multiplex congenital (AMC), and children with Morquio syndrome compared to TDY (p < 0.002). Among diagnostic groups, global function was higher (p < 0.0001) in people with achondroplasia (83(2)), compared to people with AMC (73(3)), CP (72(2)), and Morquio syndrome (66(4)). Global functioning was higher in people with AMC (p < 0.05) and CP (p < 0.01) compared to Morquio. Despite functional differences, there were no significant differences between the four diagnoses in pain (p > 0.10). Happiness was lower in people with CP (80(3)) compared to achondroplasia (90(3); p = 0.01). GMFM-D was associated with the PODCI mobility domains for all diagnoses (r = 0.31 to 0.79, p < 0.03), but was not correlated with the happiness domain for any group (r = −0.16 to 0.092; p > 0.14). GMFM-D and PODCI pain scores were correlated only in children with achondroplasia (r = 0.355; p < 0.001).

Conclusions: Significant limitations in HRQOL are seen in children with the most common physical disabilities of childhood. Pain is present at higher levels than non-disabled peers and tends not to be related to low motor function. Happiness was also not associated with gross motor function, suggesting the need to examine other contributors when mental health concerns exist in children with physical disabilities.

Significance: It is essential to utilize patient-reported outcomes to best understand and assist in the management of HRQOL in children and adolescents with lifelong physical disabilities.

EPOS/POSNA Abstract Book (49)

OP-90

What is the prevalence of depressive symptoms and antidepressant use among adult patients with cerebral palsy?

Michael G. Vitale, Chun Wai Hung, Daniel Linhares, Afrain Z. Boby, Hiroko Matsumoto, Joshua E. Hyman, David P. Roye

Columbia University Medical Center, NY, USA

LOE-Prognostic-Level III

Purpose: Depressive symptoms are reported to be higher for individuals with cerebral palsy (CP); however, as patients with CP often lack effective means of communication, the prevalence of depression may be underestimated. The objective of this study was to better understand the prevalence of depression in the CP population as determined by self-reported depressed mood and/or prescribed antidepressants (as a surrogate measure in patients unable to provide self-report).

Methods: This retrospective cohort study examined adults (≥18 years) with CP seen in an academic medical center from 2006 to 2016. The associations between depression and patient characteristics (demographics, comorbidities, gross motor function, medication) were analyzed to determine any association with depression. We also identified commonly used antidepressants.

Results: In total, 101 of 501(20.2%) CP patients (31+ 13 years, 53% F) met the criteria for depression. Of the patients without CP, 31/240 (13.1%) met the criteria for depression. The depressed and non-depressed groups did not differ in age, weight, height, body mass index (BMI), or gender. There was no significant difference in depression between ambulatory and non-ambulatory patients (21% versus 19%, p = 0.7). GI comorbidity, stimulants, antipsychotics, analgesics, benzodiazepines, and antispasmodics use were associated with higher rates of depression (p < 0.05). Selective serotonin reuptake inhibitors (SSRIs) were the most prescribed antidepressants.

Conclusions: One of five adult CP patients in our sample met the criteria for depression, a substantially greater rate than that identified through self-report alone. Although ambulatory status was not found to be associated with depression, non-ambulatory patients are more likely to have difficulty communicating their symptoms, which could confound estimates of depression prevalence in this population.

Significance: The significance of this study lies in uncovering a potentially underestimated prevalence of depression among individuals with CP. Our study reveals that 20.2% of adult CP patients met the criteria for depression—significantly higher than estimates based solely on self-report. The findings emphasize the limitations of relying on self-disclosure in a population where effective communication may be challenging. In addition, the study identifies associations between depression and various patient characteristics, shedding light on factors that may contribute to depressive symptoms in this population. The results underscore the critical importance of employing comprehensive screening measures beyond self-report to accurately assess and address depression in individuals with CP.

OP-91

Accuracy and reliability of mobile app–enhanced observational gait analysis in children with cerebral palsy

Donald T. Kephart, Jon R. Davids, Vedant A. Kulkarni

Shriners Children’s Northern California, Sacramento, CA, USA

LOE-Diagnostic-Level I

Purpose: Three-dimensional gait analysis (3DGA) is the gold standard for quantifying gait deviation in children with cerebral palsy (CP). Where 3DGA is unavailable, observational gait analysis using the Edinburgh Visual Gait Score (EVGS) has shown moderate reliability and accuracy. The addition of mobile app slow-motion video analysis may improve the accuracy and reliability of this technique. This study prospectively evaluates the accuracy and reliability of mobile app–enhanced observational gait analysis (mOGA) when compared to the gold standard of 3DGA in children with CP.

Methods: Slow-motion gait video was captured using two Apple iPhone 8S units while simultaneous 3DGA was acquired using a 12-camera infrared system. Using a low-cost commercially available slow-motion video analysis mobile app (Dartfish Express) on an iPad Pro, two observers (orthopedic surgery resident and attending pediatric orthopedic surgeon) made 11 quantitative mOGA measurements per limb. Inter-class correlation coefficient (ICC) was used to compare reliability between observers and between methods. Pearson’s correlation coefficient and Spearman’s rank correlation coefficient were used to determine correlation of error magnitude with Gait Profile Score and Gross Motor Function Classification System (GMFCS), respectively.

Results: Thirty-five subjects with CP were recruited for the study (26 M, 9 F; GMFCS I = 7; GMFCS II = 21, GMFCS III = 7; mean = 12 years, range = 6–18 years). Subjects had significant gait deviation as measured by the Gait Profile Score (GPS), with a mean GPS of 12.55 (SD = 3.97). There was excellent overall reliability between raters for the mOGA technique (ICC = 0.964). Of the 11 mOGA measurements, inter-rater reliability was good to excellent (ICC > 0.75) for nine measurements and moderate (ICC = 0.5–0.75) for two measurements. When compared with the gold standard of 3DGA, mOGA had excellent reliability for both the less experienced (ICC = 0.927) and more experienced (ICC = 0.947) rater. Reliability between mOGA and 3DGA was good to excellent for six measurements, with no measurement having poor reliability (ICC < 0.5) and all measurements having acceptable error magnitude. The error magnitude was not correlated to GPS or GMFCS (p > 0.05), indicating that the technique could be used in patients with increased gait deviation and functional impairment.

Conclusions: mOGA has good reliability between raters and acceptable accuracy compared with 3DGA.

Significance: mOGA in children with CP can allow for enhanced communication between providers using low-cost technology. Further studies should clarify the role of mOGA in assisting with treatment decision-making and outcome assessment in environments where 3DGA is not possible or available.

EPOS/POSNA Abstract Book (50)

OP-92

The risk factors associated with increased anterior pelvic tilt in ambulatory children with cerebral palsy

Chris Church, Jose De Jesus Salazar-Torres, Tanmayee Joshi, Nancy Lennon, Thomas Shields, John Henley, Freeman Miller, M. Wade Shrader, Jason Howard

Nemours Children’s Health, Wilmington, DE, USA

LOE-Not Applicable-Level III

Purpose: Anterior pelvic tilt (APT) is common in children with cerebral palsy (CP) and may be associated with excessive lumbar lordosis, back pain, and functional limitations. Factors related to increased APT are unclear but may be associated with hamstring length, proximal muscle strength, sagittal plane gait deviations, or orthopedic surgery. This study aims to determine risk factors for pathologic change in APT in ambulatory children with CP.

Methods: In this institutional review board (IRB)-approved retrospective study, ambulatory children with bilateral spastic CP were identified from our institutional gait lab database from 2002 to 2022. Pairs of gait analyses were used to measure change in APT with and without surgical interventions. A mixed-effects linear regression analysis was conducted to predict which patient and surgical factors influenced change in APT between gait analyses. A logistic mixed-effects generalized linear regression was also performed to identify factors associated with an APT increase of 5° or 10°.

Results: In total, 528 children with CP were analyzed, 422 in the surgical group (GMFCS level I (n = 35), II (n = 281), III (n = 106)) and 106 in the non-surgical group (GMFCS level I (n = 17), II (n = 64), III (n = 25)), with mean ages of 11.1 ± 3.8 and 10.0 ± 3.6 years at first gait analysis and of 13.2 ± 6.2 and 12.3 ± 3.8 years at the follow-up gait analysis, respectively. Both the surgical and non-surgical groups exhibited APT at last follow-up, at 20° ± 9° and 20° ± 9°, respectively (p = 0.63). Prior rhizotomy and hamstring lengthening (medial, medial + lateral) were significant factors for increasing APT, while Achilles lengthening, jump gait pattern, increased stance hip flexion, and high initial APT, were related to decreasing APT (Table 1). The mean change in APT after medial and medial + lateral hamstring lengthening was 1° ± 9° (p = 0.046) and 4° ± 9° (p < 0.0001), respectively. The mean change in APT in children with history of rhizotomy was 2° ± 11° (p = 0.44).

Conclusions: Rather than being solely related to hamstring lengthening, factors associated with changes in APT were multifactorial, with prior rhizotomy having the most profound effect. Contrary to conventional thinking, the presence of high initial APT was not a risk factor for further progression. Factors associated with ankle equinus—jump gait and Achilles lengthening—also had a protective effect.

Significance: Identified risk factors for change in APT should be considered when developing treatment programs for children with bilateral CP, particularly for those with a normal or retroverted pelvis given their inherent susceptibility to worsening pelvic tilt.

EPOS/POSNA Abstract Book (51)

OP-93

The association between increase in knee range of motion and patient satisfaction after rectus femoris transfer in cerebral palsy

Mauro Cesar Morais Filho, Marcelo Hideki Fujino, Catia Miyuki Kawamura, Jose Augusto Fernandes Lopes

Ageu Saraiva AACD, São Paulo, Brazil

LOE-Prognostic-Level III

Purpose: The purpose of this study was to analyze the association between patient satisfaction and increase in knee range of motion (KRM) after rectus femoris transfer (RFT) in cerebral palsy (CP).

Methods: Ninety-eight patients with spastic diplegic CP, Gross Motor Function Classification System (GMFCS) I–III, and who underwent RFT, with pre- and postoperative gait analyses, were included in the study. They were divided into three groups according to the change in KRM after RFT: (1) Group reduction (GR): reduction > 1 standard deviation (SD); (2) Group unchanged (GU): reduction or increase ≤ 1 SD; and (3) Group improvement (GI): increase > 1 SD. Demographic data, kinematics, Gait Deviation Index (GDI), and self-reported questionnaire were analyzed, and the results compared among groups.

Results: The mean age at surgery and the follow-up time were 14.2 and 3.04 years, respectively. After surgical intervention, the KRM was reduced in 6 (6.1%), unchanged in 69 (70.4%), and increased in 23 (23.5%) patients. No comparisons were made with GR due to the small number of patients in this group (6). Age at surgery (GU 14.3 years/GI 14.3 years), follow-up time (GU 3.2 years/GI 2.7 years), GMFCS distribution, GDI increase (GU 8.1/GI 11), increase in peak knee flexion in the swing phase (GU 6.40/GI 7.30), and change in Gillette Functional Assessment Questionnaire walking ability score (GU + 0.8/GI −0.1) showed no difference when comparing GU and GI. The minimal knee flexion in stance phase was reduced (−14.30) in GI and increased (+4.80) in GU (p < 0.001). The prevalence of other surgical procedures performed concomitant to RFT was also similar between GU and GI, except for hip adductor surgical lengthening, which was observed in 13% of the patients in GU and 34.8% in GI (p = 0.02). Finally, 24.6% of the patients from GU and 13% from GI were extremely satisfied with the treatment results (p = 0.243), whereas 34.8% of the patients in both groups were satisfied. According to the parents’ perspective, 23.2% from GU and 13% from GI were extremely satisfied (p = 0.298), whereas 36.2% from GU and 39.1% from GI were satisfied with the outcome (p = 0.803).

Conclusions: In the present study, the increase in KRM after RFT was related to reduction of knee flexion in stance phase. The improvement in KRM did not generate higher levels of satisfaction with treatment.

Significance: The outcomes after RFT in CP have been frequently analyzed using tridimensional gait analysis. The evidence regarding patient satisfaction regarding this procedure remains scarce.

OP-94

Is the CPCHILD questionnaire responsive—assessing HRQoL changes and performance of the CPCHILD after hip and spine surgery in children with severe cerebral palsy

Lennert Plasschaert, Patricia E. Miller, Rachel DiFazio, Brian D. Snyder, Colyn Watkins, Travis Matheney, Benjamin J. Shore

Boston Children’s Hospital, Boston, MA, USA

LOE-Not Applicable-Not Applicable

Purpose: Non-ambulant (Gross Motor Function Classification System (GMFCS) IV and V) children with cerebral palsy (CP) undergo surgical interventions designed to manage pain, facilitate seating, and improve their health-related quality of life (HRQoL). The CPCHILD questionnaire was specifically designed to measure HRQoL in children with severe non-ambulatory CP and has been shown valid and reliable. However, the responsiveness and sensitivity to change of all CPCHILD domains has yet to be demonstrated in this population. Therefore, the purpose of this study was to report the responsiveness of the CPCHILD in non-ambulant children with CP undergoing hip and spine surgery.

Methods: Parents or caregivers of non-ambulant children with CP undergoing spine or hip surgery at our hospital between 2011 and 2019 completed the CPCHILD questionnaire at baseline and 6, 12, and 24 months post-operative. This prospectively collected cohort was used to assess the responsiveness of the CPCHILD domains, as measured by the standard response mean (SRM) and the effect size (ES). Sensitivity to change was assessed by the standard error of measurement (SEM) and the minimal detectable change at the 90% confidence level (MDC90) from preoperative measurement to each follow-up measurement.

Results: One-hundred and eight patients with CP (38% GMFCS level IV; 62% level V) underwent spine or hip surgery at a mean age of 11.5 years (SD = 4.2). There were no statistically significant differences in cohort characteristics at each follow-up measurement. At 24 months of follow-up, significant score improvements were seen in the personal (6.5, SD = 21.2; 95% confidence interval (CI) = 1.6–11.5; p = 0.01), positioning (7.8, SD = 15.7; 95% CI = 4.1–11.5); p < 0.001), and health (4.9, SD = 20.0; 95% CI = 0.3–9.5; p = 0.04) domains. A small ES and SRM were detected in the personal domain (ES, 0.39; SRM, 0.44), a moderate ES and SRM were detected in the positioning domain (ES, 0.54; SRM, 0.70), and a small ES and SRM were detected in the health domain (ES, 0.28; SRM, 0.32). The SEM and MDC90 for the personal domain were, respectively, 4.7 and 9.2 points, for the positioning domain 4.1 points and 8.1 points, and for the health domain 4.9 points and 9.6 points.

Conclusions: The CPCHILD questionnaire is currently our best tool to assess HRQoL in children with severe CP; however, we found only the Personal, Positioning, and Health domains to be responsive to change after spine and lower extremity orthopedic surgery.

Significance: Surgeons should interpret CPCHILD scores with caution as not all domains are responsive to change after orthopedic surgery.

OP-95

Disease-modifying therapy changed the natural course of spinal muscular atrophy type 1: what about spine and hip?

Niyazi Erdem Yasar, Guzelali Ozdemir, Elif Uzun Ata, Naim Ata, Mahir Mustafa Ülgü, Ebru Dumlupinar, Suayip Birinci, Izzet Bingöl, Senol Bekmez

Ankara Bilkent Children’s Hospital, Ankara, Turkey

LOE-Therapeutic-Level IV

Purpose: Spinal muscular atrophy (SMA) type 1 has a devastating natural course. Scoliosis and hip subluxation are common in non-ambulatory patients with SMA. Nusinersen, the first Food and Drug Administration-approved therapy for SMA, has not only prolonged survival, but has also improved motor function in SMA type 1. However, the impact of Nusinersen treatment on the development of spine and hip deformities remains unclear.

Methods: We conducted a retrospective electronic health record database review. We included patients with SMA type 1 born between 2017 and 2021, the diagnosis confirmed by genetic testing and received intrathecal Nusinersen (Spinraza®) therapy. Patients having <2 years radiological follow-up, inadequate clinical or radiographic data, first Nusinersen dose >6 months old, and SMA treatment other than Nusinersen were excluded. We obtained demographic parameters, age at first Nusinersen dose, total number of intrathecal Nusinersen administrations, and Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP-INTEND) assessment scores of motor function. Radiological evaluation was also performed to assess parasol rib deformity, scoliosis, pelvic obliquity, and hip subluxation.

Results: We included 29 patients, mean age 3.7 ± 1.1 years (range, 2–6 years), male to female ratio 1.07. Mean number of intrathecal Nusinersen administrations was 8.9 ± 2.9 (range, 4–19). There was a significant correlation between CHOP-INTEND score and number of Nusinersen administrations (r = 0.539, p = 0.05). Correlations between CHOP-INTEND score and patient age (r = 0.361) or age at first Nusinersen dose (r = 0.39) were not significant (p = 0.076 and p = 0.054, respectively). 93.1% of the patients had scoliosis, 69% had pelvic obliquity, and 60.7% had hip subluxation, after a mean 3.3 ± 1.1 years of follow-up (range, 2–6). Distribution of age, total number of Nusinersen administrations, age at first Nusinersen dose, and CHOP-INTEND scores were the same across patients with or without scoliosis, pelvic obliquity, and hip subluxation. There was also no significant correlation between these parameters and progression rate of scoliosis, hip subluxation, or pelvic obliquity.

Conclusions: Prior to the introduction of disease-modifying therapies, management of musculoskeletal deformities was rarely discussed in SMA type 1 due to limited survival. Although Nusinersen treatment changed the natural course of SMA type 1 in terms of overall survival and motor function, progressive scoliosis and hip subluxation remain significant problems in most cases.

Significance: Significant improvements in SMA type 1 regarding overall survival and motor function in the disease-modifying therapy era should encourage us to reconsider our management algorithms for treating spine deformity and hip subluxation, from only observation toward surgical reconstruction.

EPOS/POSNA Abstract Book (52)

OP-96

Increased knee range of motion in patients with arthrogryposis: minimum 2-year follow-up

Aaron Huser, Michael William Brown, Arun R. Hariharan, Hans K. Nugraha, David S. Feldman

Paley Orthopedic and Spine Institute, West Palm Beach, FL, USA

LOE-Therapeutic-Level IV

Purpose: Arthrogryposis describes several conditions characterized by multiple congenital joint contractures. Surgical interventions for knee flexion contractures have achieved extension to redirect the arc of motion and improve ambulation but have not demonstrated maintained increases in total range of motion (ROM) over time. The purpose of this study is to review our patients’ latest ROM and ambulation status that underwent posterior knee release, proximal femoral shortening, and peroneal nerve decompression.

Methods: A retrospective chart and radiographic review was performed on patients presenting with arthrogryposis from 2016 through September of 2021 who underwent the above procedure. Patients were included if they had a minimum 2-year follow-up. Charts were reviewed for preoperative and latest follow-up ROM, ambulation status, and any complications. An immediate postoperative ROM was also reviewed to determine if there were any decreases over time. Group comparisons were performed with Friedman’s test and pairwise comparisons were performed using Dunn’s test. Fisher’s exact test was used to compare preoperative and most recent follow-up ambulation.

Results: Twenty-nine patients with 51 limbs were included in the final analysis. The mean age at surgery was 6.0 years (± 3.4 years). The mean follow-up was 40.5 months (± 15.1 months). The median preoperative flexion deformity was 45° (interquartile range (IQR) = 20°) and this improved to 3° (IQR = 12°) (p < 0.0001). The mean preoperative arc of motion was 50° (IQR 30°) and this improved to 85° (IQR 30°) (p < 0.0001). No changes in ROM occurred between immediate postoperative ROM and most recent follow-up (Figure 1). Thirty-eight percent of patients were able to ambulate preoperatively and this improved to 93% at most recent follow-up (p < 0.0001). Sixteen of 29 patients had at least limited ability to ambulate in the community, and 11/29 were home ambulators. Ten patients experienced a complication during the follow-up period. Five patients had postoperative neuritis which was treated conservatively with gabapentin and eventually weaned off. Five patients sustained fractures: three intraoperatively, requiring pinning of the distal femoral physis, one in the acute postoperative period, which was treated conservatively, and one patient sustained a femur fracture at 29 months and required fixation in the operative theater.

Conclusions: Posterior knee release with proximal femoral shortening and peroneal nerve decompression achieved increased and maintained ROM in patients with knee flexion deformities at a minimum 2-year follow-up. In addition, over 90% were at least home ambulators.

Significance: This study demonstrates maintained knee ROM and ambulation improvements at a minimum 2-year follow-up using a novel technique.

EPOS/POSNA Abstract Book (53)

OP-97

Obesity-related alterations in capital femoral epiphysis morphology: an extensive analysis of 8717 hips utilizing automated 3D-CT imaging

Eduardo Novais, Mohammadreza Movahhedi, Mallika Singh, Nazgol Tavabi, Shanika De Silva, Sarah D. Bixby, Ata M. Kiapour

Boston Children’s Hospital, Boston, MA, USA

LOE-Diagnostic-Level IV

Purpose: The epiphyseal tubercle provides stability to the capital femoral epiphysis and acts as a rotational pivot point in slipped capital femoral epiphysis (SCFE). A posterior tilt of the epiphysis (retroversion) is recognized as a crucial factor in SCFE development. This study investigates the impact of childhood obesity on the morphology of the capital femoral epiphysis in children without pre-existing hip disorders.

Methods: After institutional review board (IRB) approval, we included patients aged 7–19 years who had undergone pelvic computed tomography (CT) from 2012 to 2022. Inclusion criteria were no documented bone/joint disorders and quality for three-dimensional (3D) segmentation. We applied validated custom software (VirtualHip) for automated femoral head and neck segmentation. We measured epiphyseal tubercle height, peripheral cupping (12 o’clock position), and epiphyseal tilt. Bilateral measurements were averaged. We modeled the association between body mass index (BMI) and each measurement using linear models. We compared the mean differences in the measurements for each BMI group at each age using t-tests and corrected the p-values for multiple testing using the Bonferroni method.

Results: Our study encompassed 8717 patients, equally distributed across the sexes. The average BMI percentile was 61% ± 33%, with 24% classified as obese (BMI >= 95th percentile). After adjusting for age and sex, obese subjects had reduced epiphyseal tubercle height (estimated differences: −0.6% (95% confidence interval (CI): −0.8 to −0.4; p < 0.001)), a more posteriorly tilted epiphysis (estimated difference: −1.6% (95% CI: −2.2 to −1.0)), and decreased peripheral cupping (estimated difference: −0.3% (95% CI: −0.6 to −0.1)) compared to non-obese counterparts. Figure 1 shows trends concerning the measurements across all age groups. A smaller epiphyseal tubercle and a more posteriorly tilted epiphysis in obese children were consistent findings across all age groups until approximately age 14 (Table 1). Peripheral cupping was statistically lower in obese compared to non-obese individuals after age 13.

Conclusions: In this comprehensive automated 3D analysis of pelvic CT scans encompassing 8717 subjects, our observations underline that obese children exhibit a smaller epiphyseal tubercle, greater posterior tilt of the epiphysis, and reduced peripheral cupping compared to their non-obese counterparts.

Significance: Our study describes the impact of obesity on capital femoral epiphysis development in children. The reduced epiphyseal tubercle and diminished peripheral cupping observed in obese children are morphological features known to compromise epiphyseal stability, while posteriorly tilted epiphysis increases shear forces on the growth plate, thereby increasing the risk of slip. These findings contribute to our understanding of the pathomechanics underlying the association between obesity and SCFE.

EPOS/POSNA Abstract Book (54)

OP-98

Intraoperative perfusion monitoring does not reliably predict osteonecrosis following treatment of unstable SCFE

Bridget Ellsworth, Julianna Lee, Wudbhav N. Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Prognostic-Level IV

Purpose: Avascular necrosis (AVN) remains the most dreaded complication of unstable slipped capital femoral epiphysis (SCFE) treatment. Newer closed reduction techniques (with perfusion monitoring) have emerged as a technically straightforward means to address residual SCFE deformity while still minimizing the risk of osteonecrosis. However, limited data exist regarding the reliability of perfusion monitoring to predict the development of AVN. The purpose of this study was to evaluate this reliability.

Methods: We retrospectively reviewed all patients with unstable SCFE who underwent closed or open reduction with epiphyseal perfusion monitoring using an intracranial pressure (ICP) probe from 2015 to 2023 at a single institution with minimum 6-month radiographic follow-up. Demographic, clinical, and radiographic data were recorded, including duration of symptoms, type of reduction, capsulotomy performed, presence of a waveform on ICP monitoring after epiphyseal fixation, and development of AVN on follow-up radiographs.

Results: Our cohort included 33 hips (32 patients). The average age was 12.5 ± 1.8 years, with a median follow-up of 13.9 months. Eleven hips were treated with open reduction using the modified Dunn technique (10 hips) or anterior approach (1 hip), and 22 hips were treated with inadvertent (5 hips) or purposeful closed reduction using the Leadbetter technique (17 hips). Overall, 7 of 33 hips (21.2%) developed AVN, 5 of which (16.7%) had a pulsatile waveform intraoperatively on perfusion monitoring. The incidence of AVN after closed reduction with a detectable waveform was 25% (5 of 20 hips). There was no significant association between time to surgery (p = 0.273) or type of reduction (p = 0.378) and incidence of AVN.

Conclusions: In this series, the presence of a pulsatile waveform on intraoperative epiphyseal perfusion monitoring during reduction of unstable slips did not preclude the development of AVN.

Significance: To our knowledge, this is the first study to report development of AVN after demonstrable intraoperative epiphyseal perfusion following closed reduction of unstable slips.

OP-99

Bone scintigraphy can predict post-operative femoral head avascular necrosis in children with hip trauma and slipped capital femoral epiphysis

Patrick Curran, Katharine Hollnagel, James David Bomar, V. Salil Upasani

Rady Children’s Hospital, San Diego, CA, USA

LOE-Diagnostic-Level III

Purpose: Femoral head avascular necrosis (AVN) is a devastating complication that can occur in the setting of trauma to the hip. Bone scintigraphy (BoS) can be used to evaluate femoral head perfusion, but current evidence in support of its use in the pediatric population is lacking. The purpose of this study was to test the hypothesis that BoS would have high sensitivity and specificity to accurately diagnose femoral head AVN.

Methods: We performed a retrospective review of patients who underwent BoS to assess femoral head perfusion following treatment of traumatic femoral neck fracture, hip dislocation, or slipped capital femoral epiphysis (SCFE) at a single pediatric tertiary referral center. All patients had minimal clinical follow-up of 1 year. Assessment of intra-operative femoral head perfusion was also recorded if performed. Results of BoS and intra-op assessments were compared to radiographic findings of AVN at final follow-up.

Results: Thirty patients (47 hips) (23 M, 7 F; age: 12.8 ± 1.6 years; follow-up: 24.5 ± 15.3 months) were included. Radiographic AVN (RAVN) developed in 13% of hips. Seven hips had an abnormal BoS: 6 hips had absent perfusion and 1 hip had diminished perfusion. All six hips with absent perfusion went on to develop RAVN with collapse. The hip with diminished perfusion did not go on to femoral head collapse. No hip with normal BoS developed radiographic evidence of AVN at final follow up. Twenty-one hips underwent intra-op perfusion assessment, 15/21 were evaluated with femoral head drilling with 3/15 indicating absent perfusion. Fourteen of 21 were evaluated with intraosseous pressure (IOP) monitoring with 2/14 indicating absent perfusion. Eight of 21 hips were evaluated with both techniques with concordant absent perfusion in 1/8 hips, and this finding of absent perfusion was not noted on BoS and this hip did not develop RAVN. BoS demonstrating absent perfusion had a sensitivity of 100% and a specificity of 98% in predicting RAVN. Evidence of femoral head perfusion at the time of surgery (drilling or IOP) had a sensitivity of 17% and a specificity of 79% in predicting RAVN.

Conclusions: BoS demonstrates high sensitivity and specificity for predicting RAVN and femoral head collapse postoperatively in the setting of trauma and SCFE compared to intra-operative assessments.

Significance: Clinicians should have increased suspicion for impending femoral head collapse if there is absent perfusion on BoS at 6–12 weeks post-op, even with evidence of preserved femoral head perfusion at the time of surgery. Early diagnosis of AVN can allow for earlier interventions to improve femoral head perfusion prior to femoral head collapse.

OP-100

Epiphyseal stability increases specificity of the Loder classification system in prognosticating AVN after slipped capital femoral epiphysis

Katherine Sara Hajdu, Emilie Amaro Zoldos, Courtney Baker, Simone Herzberg, Benjamin Asbury, Stephanie N. Moore-Lotridge, Kevin Michael Dale, David Ebenezer, Nathaniel Lempert, Craig R. Louer, Jeffrey E. Martus, Gregory A. Mencio, Jonathan G. Schoenecker, Vanderbilt SCFE Study Group

Vanderbilt University Medical Center, Nashville, TN, USA

LOE-Not Applicable-Level III

Purpose: Avascular necrosis (AVN) of the femoral head is the leading cause of morbidity following slipped capital femoral epiphysis (SCFE). To identify patients at risk for AVN, Loder developed a classification system based on weight-bearing status (WBS). While sensitive in predicting which patients are at risk for AVN, determining the Loder classification can be subjective and lacks specificity for AVN. We hypothesized that only Loder-unstable patients with epiphyseal instability are at risk of AVN.

Methods: Retrospective chart review of SCFE patients who underwent closed operative treatment at a single institution from 2007 to 2022. Patient data, surgical details, and all imaging were analyzed. Loder status was determined by whether the patient could independently weight-bear (WB) at presentation. Epiphyseal instability was defined as a change from preoperative to postoperative Southwick angle (SWA) over 15 degrees with an operative note documenting a successful reduction, indicating there was relative motion between the epiphysis and metaphysis. The primary outcome was postoperative AVN rate. Statistical analysis was performed using R (version 4.3.1).

Results: There were 458 hips in 397 patients identified. Three hundred sixty-six (80%) hips were Loder-stable with a 0% AVN rate at median follow-up of 15 months (range, 7–35 months). Ninety-two (20%) hips were Loder-unstable, with an 11% (10/92) AVN rate at median follow-up of 16 months (range, 4–43 months). Of the Loder-unstable patients, 34% (31/92) were epiphyseal-stable and 66% (61/92) were epiphyseal-unstable. The AVN rate of the Loder-unstable/epiphyseal-stable patients was 0% (0/31) at a median follow-up of 12 months (range, 12–32 months). The AVN rate of the Loder-unstable/epiphyseal-unstable was 16% (10/61) at a median follow-up of 19 months (range, 4–48 months) (Table A). The addition of epiphyseal stability as a classifier significantly increased the specificity of predicting AVN (p = 0.005) (Table B).

Conclusions: The Loder classification is a sensitive preoperative screening tool for predicting risk of AVN following SCFE resulting in no false negatives. Epiphyseal stability, diagnosed intraoperatively, is an additional classifier that increases the specificity of predicting AVN risk without sacrificing sensitivity. Patients with confirmed epiphyseal instability are at the greatest risk of AVN and may benefit from perioperative and postoperative imaging or interventions.

Significance: The addition of epiphyseal stability to the Loder classification increases physicians’ ability to identify patients at risk for developing AVN. Intraoperative assessment of epiphyseal stability is essential for treatment algorithms and counseling families. The results help explain the wide range of AVN rates for Loder-unstable patients in the literature as epiphyseal stability has not been previously accounted for.

EPOS/POSNA Abstract Book (55)

OP-101

Rate and risk factors for contralateral slippage in adolescents treated for slipped capital femoral epiphysis: a comprehensive analysis of 3528 cases

David Momtaz, Rishi Gonuguntla, Aaron Singh, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh

Washington University School of Medicine, Saint Louis, MO, USA

LOE-Prognostic-Level III

Purpose: After a unilateral slipped capital femoral epiphysis (SCFE), the contralateral hip is at risk for a subsequent SCFE. However, further information regarding risk factors involved in the development of contralateral hip SCFE must be investigated. The purpose of the study was to report the rate and risk factors for subsequent contralateral SCFE in adolescents treated for unilateral SCFE.

Methods: A case-control study utilizing aggregated multi-institutional electronic medical record (EMR) data between January 2003 and March 2023 was conducted. Skeletally immature children diagnosed with SCFE who underwent surgical management were included. Variables associated with contralateral SCFE were identified using multivariate logistic regression models that adjusted for patient characteristics and time of surgery, providing adjusted odds ratios. False discovery rate was accounted for via the Benjamini–Hochberg method.

Results: 15.3% of patients developed contralateral SCFE with a mean of 296.53 (± 17.23 SE) days and a median of 190 days following their initial SCFE. Increased thyrotropin (odds ratio (OR) = 1.43, p = 0.036), diabetes mellitus (OR = 1.67, p = 0.005), severe obesity (OR = 1.81, p < 0.001), history of human growth hormone (HGH) use (OR = 1.85, p < 0.001), low vitamin D (OR = 5.75, p < 0.001), younger age (boys under 12 years of age (OR = 1.85, p < 0.001), and girls under 11 years of age (OR = 1.47, p = 0.026)), and tobacco exposure (OR = 2.43, p < 0.001) were significantly associated with an increased odds of developing contralateral disease.

Conclusions: In the largest study on this topic, we identified the rate, odds, and risk factors associated with development of contralateral SCFE. We found younger age, hypothyroidism, severe obesity, low Vitamin D, diabetes mellitus, and history of HGH use as independent risk factors.

Significance: Our findings can aid clinical decision making in at-risk patients.

EPOS/POSNA Abstract Book (56)

OP-102

Temporary in situ pinning with subsequent modified Dunn is a safe alternative to primary modified Dunn

Jordyn Adams, Graham Whiting, Jordan Archer, Courtney Selberg

Children’s Hospital Colorado, Aurora, CO, USA

LOE-Therapeutic-Level II

Purpose: Surgical hip dislocation with modified Dunn (MD) is a viable treatment option for moderate to severe unstable slipped capital femoral epiphysis (SCFE) at an experienced tertiary care center. In the acute setting, an experienced surgeon may not be immediately available for MD. However, in situ pinning (ISP) is a well-accepted treatment in the acute setting and is more familiar to the on-call orthopedic surgeon. To date, no literature exists on the impact of temporary ISP prior to MD to compare its impact on outcome. Our primary aim was to compare complication rate and radiographic outcome at 2 years in patients with moderate/severe unstable SCFE undergoing primary MD versus ISP with subsequent MD.

Methods: Thirty-one patients underwent treatment for moderate/severe SCFE at a single institution. Demographics, surgical characteristics, and radiographic measurements were compared. Investigation of treatment outcomes was performed using linear regression models, adjusted for age and sex, to analyze continuous variables across ISP + MD and MD only treatment groups. Mean and standard deviation were calculated to summarize continuous variables, and the mean difference between treatment groups with a 95% confidence interval was calculated from the linear regression model for slip angle. Binary outcomes were explored through logistic regression models again adjusted for age and sex. The Wilcoxon rank-sum test assessed the significance of Merle d’Aubigné scores between the two groups.

Results: Fifteen patients underwent ISP with subsequent MD; 16 patients underwent primary MD. Average time between ISP and MD was 47.86 days. There was no difference in demographic characteristics, preoperative Southwick angle, alpha angle, or body mass index (BMI). Implant failure rate was 6.67% (ISP + MD) and 6.25% (MD), p = 0.094; both occurred at 3 months postoperatively and required upsizing of femoral neck implants without loss of initial correction. The incidence of AVN was not significantly different between groups; 6.67% ISP + MD versus 12.5% MD, p = 0.443. Merle d’Aubigné scores at final follow-up were 18 (ISP + MD) and 17 (MD), p = 0.581. There was no significant difference between groups in Tonnis grade, Southwick, or alpha angles at final follow-up.

Conclusions: We demonstrate no difference in complication rate in patients with moderate/severe SCFE treated with primary MD compared to temporary ISP with subsequent conversion to MD.

Significance: Temporary ISP for moderate/severe unstable SCFE may be a safe alternative to primary MD if an experienced hip surgeon is not immediately available. This also allows additional time for patients and their family to understand the risk/benefit ratio for the MD surgery prior to conversion.

EPOS/POSNA Abstract Book (57)

OP-103

Risk factors of vitamin D deficiencies on SCFE development

David Momtaz, Abhishek Tippabhatla, Rishi Gonuguntla, Mehul Mittal, Beltran Torres-Izquierdo, Pooya Hosseinzadeh, Zachary Meyer

Washington University School of Medicine, Saint Louis, MO, USA

LOE-Prognostic-Level III

Purpose: Slipped capital femoral epiphysis (SCFE) is one of the most common hip disorders in adolescents. Multiple metabolic disorders have been associated with secondary SCFE, and the association of obesity with primary SCFE has been well studied. While the incidence of vitamin D deficiency in childhood has been increasing, few studies have examined a potential link with SCFE. This study investigates the impact of vitamin D on SCFE development and related complications.

Methods: A large comprehensive national database was queried for patients under age 9 years who have records of calcidiol lab drawn between 9 and 18 years of age. These patients are followed up until SCFE occurrences or until the patient turns 18 years. Patients were divided into vitamin D adequate (calcidiol >= 30 ng/mL) and vitamin D-deficient (calcidiol < 30 ng/mL) groups. Propensity score matching was performed adjusting for demographics and risk factors, including body mass index (BMI), medications, medical comorbidities, and laboratory values. Temporal analysis was performed comparing risks of SCFE development between the two cohorts. Statistical significance is held at 0.05.

Results: On preliminary analysis, 98,045 patients met the inclusion criteria. After matching, 34,552 in the vitamin D-deficient and 34,552 in the vitamin D-adequate groups were included. The average patient ages were 11.4 years and 50% were female. In total, 136 (0.39%) and 48 (0.14%) patients developed SCFE in vitamin D-deficient and vitamin D-adequate groups, respectively (p < 0.0001). In this study, 64.7% of SCFE development was attributed to vitamin D deficiency (risk ratio (RR) = 2.833, 95% confidence interval (CI) = 2.040–3.936; hazard ratio (HR) = 1.558, 95% CI (1.119–2.168), p < 0.0001).

Conclusions: This is one of the largest studies to date demonstrating the association between vitamin D deficiency and SCFE development. Vitamin D-deficient children are more susceptible to developing SCFE than those with adequate supplementation.

Significance: These findings highlight the importance of managing adequate vitamin D supplementation in at-risk adolescents, especially among the obese, nutrient-deficient, and populations living further from the equator to lower the risk of future SCFE development.

OP-104

Intertrochanteric Imhauser’s osteotomy combined with osteochondroplasty in management of slipped capital femoral epiphysis

Mostafa Baraka

Ain Shams University, Cairo, Egypt

LOE-Therapeutic-Level IV

Purpose: Treatment of moderate to severe stable slipped capital femoral epiphysis (SCFE) remains a challenging problem. Open reduction by modified Dunn procedure carries a considerable risk of osteonecrosis (ON). Imhauser osteotomy can realign the deformity without the risk of ON, but the remaining metaphyseal bump is implicated with significant chondro-labral lesions and accelerated osteoarthritis. We conducted this study to evaluate the efficacy and safety of Imhauser osteotomy combined with osteochondroplasty (OCP) through the surgical hip dislocation (SHD) approach.

Methods: A prospective series of 23 patients with moderate-severe stable SCFE underwent Imhauser osteotomy and OCP through SHD. The mean age was 14.4 years (13–20 years) and the mean follow-up period was 45 months (24–66 months). The outcome measures included clinical and radiological parameters, and Harris hip score (HHS) was used as a functional score.

Results: The mean HHS improved significantly from 65.39 to 93.3. The limb length discrepancy improved by a mean of 1.72 cm. The mean flexion and abduction arcs showed a significant improvement (mean increase of 37.5° and 18.5°, respectively). The mean internal rotation demonstrated the most significant improvement (mean increase of 38.5°). All the radiographic parameters improved significantly, including anterior and lateral slip angles (mean improvement 37.52° and 44.37°, respectively). The mean alpha angle decreased by 39.19°. The articulo-trochanteric distance significantly increased to a mean of 23.26 mm. No cases of ON or chondrolysis were identified.

Conclusions: Combined Imhauser osteotomy and OCP through the surgical dislocation approach provides a comprehensive and safe management of moderate to severe stable SCFE.

Significance: Additional OCP should be considered with corrective osteotomies in moderate and severe stable slips.

OP-105

Long-term outcomes for total joint arthroplasties in pediatric and young adult populations

Andrea Rogers, Gabrielle J. Patin, Carson L. Keeter, Nathan Donaldson

Children’s Hospital Colorado, Aurora, CO, USA

LOE-Therapeutic-Level II

Purpose: A growing number of pediatric and young adult patients are undergoing total joint arthroplasty (TJA) due to rheumatic, congenital, degenerative, and traumatic joint diseases as well as treatment for malignant blood disorders that lead to avascular necrosis (AVN). Surgical considerations differ from adult populations, contributing to patient and provider hesitancy. Data are now available to examine short- and medium-term clinical outcomes, but little is known about long-term functional or quality of life (QoL) outcomes.

Methods: A retrospective cohort study was performed on patients who have undergone total hip arthroplasty (THA) and total knee arthroplasty (TKA) at our institution between 2000 and 2022. Clinical data were collected from patient records. Functional outcomes were assessed using the modified Harris Hip score (HHS) and Oxford Knee score (OKS), and QoL outcomes were assessed using the 36-Item Short Form Survey (SF-36v2). Scores were averaged for each patient preoperatively, and between 0 and 6 months, 6–12 months, 1–2 years, 2–5 years, 5–10 years, and 10+ years postoperatively. Exclusion criteria included less than 5 years of follow-up, patients over age 25 at the time of surgery, TJA for oncologic treatment, and patients with mucopolysaccharidoses and other progressive degenerative diseases.

Results: In total, 112 TJAs in 95 patients were identified and consented to analysis (43% female, 55% male, 2% non-binary, average 17.3 years of age at surgery). Eighty-eight THA patients (102 TJA) provided 189 HHS responses. Scores increased by a mean of 30.3 and 38.4 points, at 6 months (n = 28) and 10+ years (n = 16), respectively, from preoperative surveys (n = 30). Seven TKA patients (10 TJA) had insufficient preoperative OKS data (n = 1) and were not included in the final analysis. Ninety-three patients (110 TJA) provided 154 SF-36vs responses. Scores increased by a mean of 16.9 and 16.7 points at 6 months (n = 27) and 10+ years (n = 13), respectively, from preoperative surveys (n = 21). Five revisions were necessary due to manufacturer implant recall (n = 3), deep infection (n = 1), and femur fracture (n = 1).

Conclusions: Study data suggests that patients under the age of 25 experience significant improvement in both QoL and functional outcomes by 6 months following TJA procedures and that these improvements are sustained for up to 10 years. Non-recall-related revision rates are also like adult population TJA revision rates within the first 10 years postoperatively.

Significance: This is one of the largest single institution samples to systemically track long-term functional and implant survivorship outcomes and one of the first to track QoL for pediatric and young adult TJA procedures.

EPOS/POSNA Abstract Book (58)

OP-106

Universal ultrasound screening for DDH may be cost effective: a Markov decision analysis model incorporating the entire lifespan

Joshua Bram, Drake Glenn LeBrun, Peter Cirrincione, Erikson Nichols, Bridget Ellsworth, Ernest Sink, Emily Dodwell

Hospital for Special Surgery, New York, NY, USA

LOE-Economic-Not Applicable

Purpose: Developmental hip dysplasia (DDH) is a common pediatric orthopedic condition with long-term implications for quality of life and is now considered the primary cause of hip arthritis requiring joint replacement. Complications of missed or delayed DDH may be minimized when diagnosed early when non-operative interventions (e.g. Pavlik harness) are highly successful. Current standard of care in the United States is selective ultrasound screening, performed only with abnormal physical examination, family history, or presence of risk factors. An updated cost-utility analysis, considering health utilities and costs, is warranted.

Methods: A Markov simulation model was designed representing six DDH screening strategies: (1) Universal ultrasound screening within first 2 weeks (USB), (2) Selective screening within first 2 weeks (SSB, high-risk patients screened with ultrasound, low-risk patients not screened), (3) Universal ultrasound screening at 6 weeks (US6), (4) Universal hybrid screening (UHS, clinical instability receives ultrasound within first 2 weeks while all others undergo ultrasound at 6 weeks), (5) German model (ultrasound for high-risk patients within first 2 weeks and all others at 6 weeks), and (6) a no screening model (i.e. natural history of untreated DDH). A standardized DDH treatment algorithm was used, and a comprehensive literature review provided relevant probabilities and incidences, Medicare costs, and utilities. A hypothetical patient cohort was modeled from birth to death capped at age 100, with sensitivity analyses performed.

Results: From a societal perspective, the US6 strategy was more effective (77.06 versus 77.00 quality-adjusted life years (QALYs)) and more costly ($5677.36 versus $5606.07) than SSB. Utilizing a willingness-to-pay (WTP) threshold of <$100,000/QALY, US6 was more cost-effective than SSB (incremental cost-effectiveness ratio (ICER) = $1111.78/QALY). From the payer perspective, a US6 approach was more costly ($4355.83 versus $4262.12) than SSB, but more cost-effective (ICER = $1461.27/QALY). The US6 strategy was overall cost-effective (<$100,000/QALY) in 59.2% of 10,000 probabilistic sensitivity analysis (Figure 1) iterations assessing societal costs (versus 27.7% UHS, 7.2% USB, and 5.9% SSB) and 58.8% of payer iterations (versus 27.5% UHS, 7.6% USB, and 6.1% SSB). The second most cost-effective model was UHS (77.04 QALYs, societal = $5721.20, payer = $4391.79).

Conclusions: Universal screening at 6 weeks of age or a universal hybrid screening model was cost-effective in screening for DDH compared to traditional selective screening models in the United States.

Significance: These results may justify updated guidelines in the United States regarding appropriate screening for DDH, bringing our standards in line with many other countries where all children are screened for DDH with ultrasound.

EPOS/POSNA Abstract Book (59)

OP-107

Deep-learning algorithm accurately measures migration percentage on hip surveillance radiographs

Vedant A. Kulkarni, Chun-Hsiao Yeh, Anna Kay, Michael Eli Firtha, Marie Villalba, Patrick Donohue, H. Graham, Unni G. Narayanan, Stella X. Yu

Shriners Children’s Northern California, Sacramento, CA, USA

LOE-Diagnostic-Level I

Purpose: All hip surveillance programs for children with cerebral palsy (CP) rely on accurate quantification of the hip migration percentage (MP) to determine referral and treatment. Accurate reporting and measurement of the MP has been shown as a substantial barrier to hip surveillance implementation. This study validates a deep-learning algorithm to automatically measure MP on hip surveillance radiographs, with the goal of allowing broader access to “specialist-level” radiographic measurement.

Methods: Pelvic and femoral landmarks relevant for the calculation for MP were labeled by pediatric orthopedic surgeons on a de-identified data set of anteroposterior (AP) pelvis radiographs of children with CP. A deep-learning algorithm to automatically detect hip landmarks and calculate the MP was then created using a ResNet 18 and Cascaded Pyramid Network architecture. The algorithm was tested for accuracy on a prospectively collected set of AP pelvis radiographs, with “ground truth” MP measurements performed by pediatric orthopedic surgeons in their actual clinical practice. The mean absolute difference (MAD) between algorithm and surgeon was calculated with linear mixed modeling, and multi-variate analysis was used to determine sources of error. The sensitivity, specificity, and area under the receiver-operating characteristic curve (AUC) were calculated with an MP > 30% representing a “positive” case.

Results: A total of 3354 pelvis radiographs from 1509 subjects with CP were included in the study (56% M, 44% F; mean age at X-ray, 8 years; 14% Gross Motor Function Classification System (GMFCS) I, 15% GMFCS II, 6% GMFCS III, 24% GMFCS IV, and 36% GMFCS V). A total of 2500 X-rays from two centers were used to develop and optimize the algorithm. In total, 854 prospectively collected X-rays from 24 different international centers were utilized as a diverse external test set. When compared to the MP measurements calculated by each center’s orthopedic surgeon, the algorithm had an MAD of 9.3% (95% confidence interval (CI): 8.7%–9.9%), sensitivity of 84% , specificity of 85%, and AUC of 0.915. Increased error was correlated most strongly with increasing MP (b = 0.117, p < 0.001), and weakly with GMFCS 5 (b = 0.04, p = 0.047), presence of femoral implant (b = 0.03, p = 0.005), and increasing age (b = 0.005, p < 0.001).

Conclusions: A deep-learning algorithm can automatically measure MP on hip surveillance radiographs with excellent discriminatory characteristics in a large and diverse set of “real world” radiographs. The measurement error of the algorithm falls within the published range of specialist error (MAD = 4%–13%).

Significance: Incorporation of this deep-learning algorithm into the clinical workflow of community and non-specialist providers may remove a substantial barrier to the implementation of hip surveillance.

EPOS/POSNA Abstract Book (60)

OP-108

Suprainguinal fascia iliaca nerve blocks outperform epidural analgesia in patients undergoing periacetabular osteotomy

David Peter VanEenenaam, Stefano Cardin, Wallis Muhly, Wudbhav N. Sankar

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Therapeutic-Level III

Purpose: Adequate pain control and early mobilization are critical in the postoperative period following periacetabular osteotomy (PAO). Regional anesthesia can reduce postoperative pain, but certain techniques can increase the risk of postoperative motor block and delayed functional recovery. Continuous lumbar epidurals can not only provide excellent analgesia but also create challenges with early ambulation. Recently, suprainguinal fascia iliaca (SIFI) single-shot blocks have been shown to provide effective analgesia in PAO patients. The goal of this study was to compare opioid use, time to achieve inpatient physical therapy (PT) goals, and length of stay (LOS) between a cohort of patients receiving SIFI blocks and a cohort of patients receiving epidural analgesia (EA).

Methods: This retrospective single-surgeon comparative cohort study included all patients who underwent a PAO between 2012 and 2022. Regional anesthetic technique (SIFI versus EA), length of hospital stay, intra- and post-operative opioid use, pain scores, and time to achievement of PT milestones prior to discharge were recorded. Patients were excluded if they had any preexisting neuromuscular syndrome or neurosensory deficit. All opioid use was converted to morphine milligram equivalents (MME) using standard conversions.

Results: A total of 204 patients met the inclusion criteria; 164 patients received EA and 32 received a SIFI block. The average age of our cohort was 19.5 years (range, 10–35 years). There were no significant differences in age, gender, race, or body mass index (BMI) between the two groups. Compared to EA patients, the SIFI block cohort had shorter mean LOS (2.9 days versus 4.1 days) (p < 0.001) and lower total opioid use on post-operative days 0–2 (p < 0.05). Time to sit on edge of bed, time to ambulate > 10 feet, and time to negotiate > 3 stairs were achieved sooner in those who received a SIFI block compared to EA (Figure 1) (p < 0.001). There were no differences in pain scores reported at inpatient PT visits.

Conclusions: After PAO surgery, the SIFI block is associated with shorter hospital LOS, reduced postoperative opioid use, and earlier mobilization when compared with those who were managed with an epidural.

Significance: This is the largest direct comparison of patients receiving SIFI blocks with those receiving lumbar epidurals for PAO surgery. Our results support the use of SIFI blocks given the equivalent pain scores, lower opiate use, faster time to ambulation, and shorter LOS.

EPOS/POSNA Abstract Book (61)

OP-109

Virtual children’s fracture clinic—a prospective study of 5536 patients confirming that efficiency and cost saving does not compromise safety

Anish P. Sanghrajka, Kareem Edres, Aly Pathan, Matthew Edward Kenneth Goodbun, Joe Hwong Pang, Graeme Carlile, Rajiv Merchant, Helen Chase

Norfolk & Norwich University Hospitals, Norwich, UK

LOE-Economic-Level II

Purpose: Virtual fracture clinics, in which patient’s notes and radiographs are reviewed after referral from the Emergency Department (ED), to plan and implement further management, have become increasingly popular in clinical practice. They reduce burden of travel for unnecessary appointments to the hospital, saving patients time and money, as well as having environmental benefits. The main concern about this method of delivery of clinical care is safety, with the potential for missed injuries as the patient is not seen or examined in person. The purpose of this study was to determine the safety of Virtual Children’s Fracture Clinics (VCFC) specifically with reference to time to review, missed/incorrect diagnoses, and return rate after discharge.

Methods: This was a prospective consecutive case series study performed at a University Teaching Hospital. The VCFC database was used to identify all patients seen between August 2017 and May 2021. Records were reviewed and data recorded about the ED diagnosis, the orthopedic diagnosis and final outcome, unplanned return to clinic for a face-to-face (F2F) review, and later referral back for the same injury.

Results: A total of 5536 consecutive patients were seen in the VCFC over the study period (cost saving £465,496). Mean time from ED visit to VCFC appointment was 2.25 days. Median follow-up at the time of this study was 31 months (range: 19–63 months). Thirty-eight patients (0.5%) required admission for urgent surgical intervention following their virtual clinic review. A total of 2325 patients (42%) were discharged from VCFC without further F2F follow-up. Sixty-three of these patients (3%) returned for unplanned F2F clinic. None were found to have missed injuries or required further interventions. The remaining 2262 patients never attended the hospital again during the entire study period, suggesting that there were no significant missed injuries. The diagnosis made in VCFC differed from ED diagnosis in 1921 cases (34%) (downgraded to a lesser injury in 1460, upgraded to more severe fracture type in 220).

Conclusions: This is the largest reported series of patients from a VCFC, with the longest follow-up, providing a solid basis for making conclusions about safety and missed/incorrect diagnoses. The VCFC model saved 110 F2F appointments per month. Our data demonstrate that the system allows prompt identification of the small number of patients requiring urgent attention and allows safe modification of the ED diagnosis without further F2F review.

Significance: A 3% return rate after discharge from a VCFC, with no missed injuries at a minimum follow-up of 19 months, confirms the safety of VCFCs. We advise those units that do not employ a VCFC model to strongly consider doing so.

OP-110

Prevalence of osteochondromas in the spine in patients with multiple hereditary exostoses

Carlos Monroig-Rivera, Lauren Bockhorn, Brenda Santillan, David C. Thornberg, Karl E. Rathjen

Scottish Rite for Children, Dallas, TX, USA

Purpose: Multiple hereditary exostoses (MHE), an autosomal dominant musculoskeletal disorder, is characterized by the development of multiple cartilage-capped exostoses originating from the physis, known as osteochondromas. The potential for these osteochondromas to impinge on the spinal cord is a clinical concern. Our study aims to determine the prevalence of osteochondromas in the spine in individuals with MHE. In addition, we aim to identify any risk factors for osteochondromas impinging on the spinal cord.

Methods: We prospectively enrolled a cohort of MHE patients/families at a single institution from 2010 to 2022. Demographics, osteochondroma location, and clinical outcomes were documented. Magnetic resonance imagings (MRIs) were obtained and interpreted by musculoskeletal pediatric radiologists. Patients were categorized based on osteochondroma location: no spinal involvement, on the spinal column, in the spinal canal, or neural impinging. We also noted when osteochondromas were present on the scapula, ribs, or pelvis (aka “harbinger lesions”).

Results: Ninety-four MHE patients received an MRI. Almost 44 (46.8%) had osteochondromas on their spine. Around 22 (23.4%) had osteochondromas located only on their spinal column, 18 (19.1%) had an osteochondroma encroaching in their spinal canal, and 4 (4.3%) were found to have one causing neural impingement (Table 1). Of the four with neural impingement, and two displayed paraparesis requiring immediate surgical intervention (Figure 1). The remaining two patients were observed clinically and monitored with serial MRIs. One patient began to exhibit worsening paretic symptoms and had excision. The remaining patient remained stable throughout follow-up. Age, gender, and presence of harbinger lesions were not associated with neural impingement although logistic regression showed Hispanic individuals were ~32.8 times more likely to have neural impingement compared to white individuals (p = 0.0419).

Conclusions: Although nearly half of patients have osteochondromas on the spine, neural impingement is rare (4.3%) and resulted in operative intervention in 75% of cases. Age, gender, and harbinger lesions were note associated with neural impingement. Significance: Although the prevalence of osteochondromas of the spine approaches 50%, neural impingement is rare. This information can be used to inform clinical decision-making regarding screening MRIs.

EPOS/POSNA Abstract Book (62)

OP-111

Predictors of complication in pediatric hardware removal

Pablo Coello, David A. Hsiou, Luke Austin Nordstrom, Todd Phillips, Rachel Silverstein, Scott B. Rosenfeld

Texas Children’s Hospital, Houston, TX, USA

LOE-Therapeutic-Level III

Purpose: Hardware removal (HWR) is a common procedure in the pediatric population. Yet, current literature is mixed on the risks and benefits especially in the elective setting. Identification of appropriate indications for HWR is essential to guiding treatment. The objective of this study was to assess the incidence of complications as well as identifying significant predictors of complications based on patient risk factors.

Methods: A retrospective cohort study was conducted using institutional CPT code 20680 database query. Patient demographics, comorbidities, peri-procedural data, and complications were recorded. Complications were subcategorized as infection, pain, and re-fracture. Data were analyzed for patient-specific and complication-specific factors.

Results: A total of 1452 patients met the inclusion criteria. The average age was 11.51 years (range, 0 + 3 to 21 + 0 years). There were 107 (7.4%) complications within the cohort, of which 44.9% were infections (75% superficial and 25% deep), 19.6% were refractures, 17.7% had pain (68.4% had pain symptoms unresolved with HWR and 31.6% had new-onset pain after HWR), and 17.8% had various other complications. The overall rate of superficial infection was 2.5%, deep infection was 0.83%, refracture was 1.44%, pain symptoms unresolved with HWR was 0.9%, and new-onset pain was 0.4%. A total of 464 (32%) patients had a comorbidity. 9.5% were diagnosed with a neuromuscular syndrome such as cerebral palsy, 2.5% had osteogenesis imperfecta (OI), 1.3% had rickets, 0.55% had Neurofibromatosis Type-1, 1.3% had a skeletal dysplasia, 2.6% had a growth plate disorder such as Blount’s disease, 4.6% had another syndrome or growth disorder such as Morquio syndrome, 0.83% had a bone disease such as fibrous dysplasia, 3.9% were obese, and 4.5% had a systemic illness/disease such as sickle cell disease. Of the 107 complications, 42% were associated with comorbidities (p = 0.019), OI having the highest at 16.2% and growth plate disorders at 15.8%. There was no difference in complications with elective versus trauma cases. For refractures after HWR, there was no difference among type of hardware used and which bone the HWR occurred. For infections, the proximal femur and the use of plates and screws had the highest infections for both superficial and deep infections.

Conclusions: The incidence of HWR-related complications is low (7.6%). Given HWR is often left to surgeon discretion without evidence-based decision making, these results can help surgeons and families to make evidence-based decisions on whether or not to remove hardware.

Significance: Help surgeons determine whether HWR is appropriate, especially in the elective setting, given the risks and benefits found in this cohort.

EPOS/POSNA Abstract Book (63)

OP-112

Significant improvement in health-related quality of life following surgical treatment of congenital muscular torticollis among a 2-year follow-up cohort of children, adolescents, and young adults

Per Reidar Hoiness, Anja Medbø

Oslo University Hospital, Oslo, Norway

LOE-Prognostic-Level II

Purpose: Surgical treatment of congenital muscular torticollis (CMT) has demonstrated clinical efficacy in cases unresponsive to conservative therapies. Nevertheless, there is a paucity of reports on self-reported outcomes and health-related quality of life (HRQoL). This study aims to assess HRQoL in children, adolescents, and young adults undergoing surgical treatment for CMT, comparing HRQoL with clinical outcomes.

Methods: We conducted a Level 2 prospective observational study on a cohort of CMT patients treated surgically at a single tertiary center. Surgical intervention was guided by clinical indicators, including sternocleidomastoid (SCM) tightness, pain, restricted neck motion, craniofacial asymmetry, and insufficient response to physical therapy. The surgical procedures focused on complete release of tightness, with routine elongation of the medial head to preserve cosmetic function. Patients underwent rigorous pre-operative and post-operative assessments, followed by long-term follow-up. A strict postoperative protocol, including stretching, physiotherapy, and positional exercises, was followed for a minimum of 6 months. Clinical outcomes were assessed using the Cheng and Tang torticollis scoring system, while HRQoL was evaluated using the PedsQL™ 4.0 generic core scales.

Results: The study comprised 31 patients with an average age of 11.4 years. Significant improvements in range of motion, deformities, and overall subjective satisfaction were observed at the 2-year follow-up. The Cheng and Tang score improved significantly from fair (9.6 points) to excellent (17.9 points) after 2 years (p < 0.001). Older patients exhibited less improvement than their younger counterparts, particularly in terms of craniofacial asymmetry (p = 0.004). Patient PedsQL scores also significantly improved at the 2-year mark (p = 0.040), with no discernible age-related differences.

Conclusions: This study demonstrates that surgical treatment significantly enhances PedsQL scores in children, adolescents, and young adults with CMT. Notably, clinical parameters such as shoulder, neck, and plagiofacial deformities showed significant improvement, particularly in younger patients. Utilizing the Cheng and Tang system, all patients achieved good or excellent outcomes, suggesting a correlation between improved clinical results and higher HRQoL post-CMT surgery. Importantly, PedsQL scores detected surgical changes, underscoring their sensitivity. Our findings underscore substantial HRQoL and clinical improvements following CMT surgery, with age-related differences, particularly in craniofacial asymmetry improvement. We recommend further research, including the development of a specific CMT HRQoL questionnaire.

Significance: This study contributes to our understanding of the effectiveness of surgical treatment for CMT and its impact on the quality of life of affected individuals. It provides valuable insights for healthcare professionals and researchers in this field.

OP-113

The hidden consequences of advanced operative spine imaging in children: do the suggested benefits of intraoperative computed tomography and navigation in posterior spinal fusion for adolescent idiopathic scoliosis outweigh the possible lifetime oncological risks of increased radiation exposure?

Bram Verhofste, Brendan M. Striano, Alex Crawford, Andrew M. Hresko, Andrew Schoenfeld, Andrew K. Simpson, Daniel Hedequist

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level II

Purpose: Adolescent idiopathic scoliosis (AIS) develops in 1%–3% of adolescents, with recent trends demonstrating increased rates of posterior spinal fusion (PSF). Advances in intraoperative computed tomography (iCT), navigation, and robotics suggest improved outcomes and safer instrumentation. However, imaging techniques expose children to varying yet often significant amounts of ionizing radiation. Furthermore, scoliosis patients accumulate exposure due to recurrent surveillance imaging. Despite the well-established dose-dependent relationship of radiation and oncogenesis, minimal data exist on the true oncological risks of advanced operative spine imaging in children. Our goal was to compare the lifetime cancer risk of iCT-navigation compared to traditional imaging techniques (non-iCT) in AIS PSF.

Methods: Retrospective analysis of AIS patients (0–18 years) treated with PSF at a quaternary pediatric center was performed (2014–2019). Demographic, surgical, deformity, and radiation characteristics were compared between groups based on intraoperative imaging technique (iCT versus non-iCT). Cumulative radiation exposure and carcinogenesis risk were calculated as total effective dose (ED) in millisieverts (mSv) based on established conversion factors utilizing age, gender, and body region. Pediatric low-dose iCT protocols were used.

Results: A total of 245 patients (mean = 14.4 years; 83% female) were included: 119 iCT (49%) were compared to 126 non-iCT (51%) (Table 1). After accounting for clinical/radiographic variations, radiation exposure was statistically different between imaging groups, with iCT patients receiving the highest degree of ionization (p < 0.001). Total ED (median; interquartile range (IQR)) per group included fluoroscopy (0.05 mSv; 0.03–0.07), fluoroscopy/radiography (4.14 mSv; 0.23–4.4), and iCT group (8.19 mSv; 5.36–11.7). Overall, iCT-navigated PSF theoretically resulted in 0.9 iatrogenic malignancies per 1000 patients (p < 0.001; IQR, 0.59–1.29), while 2.37/1000 patients (p < 0.001; IQR, 1.47–3.27) are projected to develop in patients with 3 iCT spins/acquisitions.

Conclusions: Compared to traditional non-iCT PSF, an additional 1/1000 AIS patients are expected to develop cancer directly related to iCT usage. In addition, the true incidence of carcinogenesis after a complete treatment course is likely underestimated due to cumulative radiation exposure from surveillance imaging. Further research is necessary to evaluate long-term population risks of iatrogenic imaging-induced malignancies.

Significance: Advanced operative imaging modalities are being increasingly applied in spine surgery. Despite rising trends in iCT, a paucity of data exists on the potential risks of neoplastic transformation secondary to iatrogenic, imaging-induced radiation exposure. We found an alarming incidence of anticipated cancers due to iCT which exposes patients to significantly higher ED compared to alternative techniques. The dose-dependent risk of cancer necessitates limited radiation exposure in developing children and a discussion of iCT indications/regulations is required to promote development of radiation-free imaging modalities in the biomedical sector.

EPOS/POSNA Abstract Book (64)

OP-114

Radiation shielding during bedside fluoroscopy reduces radiation exposure to pediatric patients

Steven Zhang, William Huffman, Caroline Fay, Margaret Bowen, Divya Talwar, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Diagnostic-Level II

Purpose: Pediatric patients are sensitive to the effects of radiation. There are no established standard protocols or society guidelines supporting the use of radiation shielding during bedside orthopedic procedures requiring fluoroscopic guidance despite frequent use. Consequently, there is a wide variation among institutions. Some position papers have suggested that radiation shields may actually increase radiation exposure to the patient due to scatter of the X-ray beams. In this study, we sought to quantify the amount of radiation at three critical anatomic locations using a mannequin model undergoing a simulated bedside upper extremity fracture reduction with and without lead shielding.

Methods: A mannequin (Laerdal Medical) approximating the size of an average 5-year-old was placed supine on a standard hospital stretcher. The upper extremity was extended over the image intensifier of a standard fluoroscopy machine (GE Healthcare). Exposures were performed at 110 kVp and 4.5 mA for 10 s. A dosimeter (Mirion Technologies) was used to assess scattered radiation in three locations: neck/thyroid, chest/breast, and groin. Readings were assessed with and without a standard rectangular radiation shield that spanned from the chin to the upper thighs. Each configuration was replicated five times.

Results: With no shielding, the neck/thyroid received 61.5 mSv, breast/chest received 58.2 mSv, and the groin received 39.7 mSv. These values were significantly higher (p < 0.0001) compared to the values measured at the thyroid, chest, and groin when in the presence of an anterior shield (4.1, 5.3, and 1.2 mSv, respectively) or in the presence of an anterior and posterior shield (1.4, 4.7, and 1.8 mSv, respectively.) There was no statistical difference between anterior shielding and anterior and posterior shielding in all three locations.

Conclusions: Radiation shields placed anteriorly over a pediatric patient significantly reduce the radiation exposure of pediatric patients in the neck/thyroid, chest/breast, and groin regions by an average of 20-fold. The use of a posterior shield confers no additional protection.

Significance: Although fluoroscopy is commonly used in pediatric orthopedic procedures, there remains no standard guideline for the use of radiation shielding, leading to wide variation in clinical practice. This study not only offers the first of its kind data supporting the use of anterior radiation shielding during reduction procedures where the radiation source is above the patient but also suggests that additional shielding techniques may need to be considered to reduce the exposure even further. Providers should strongly consider placing an anterior shield on the patient when performing a bedside procedure requiring fluoroscopy.

EPOS/POSNA Abstract Book (65)

OP-115

Suicidal ideation in pediatric orthopedic patients

Taylor Zak, Whitney Meghan Herge, Chan-Hee Jo, Anthony Riccio

Scottish Rite for Children, Dallas, TX, USA

LOE-Prognostic-Level III

Purpose: Suicide is the second leading cause of death among American children aged 10–18 years, and those with physical health conditions have a 20% increase in suicidal ideation (SI) relative to their healthy peers. Despite this, suicidality in children with musculoskeletal problems is largely unstudied. This study therefore aims to determine the prevalence of SI in pediatric orthopedic patients and identify risk factors for endorsem*nt of suicidality.

Methods: A retrospective review of all patients aged 10 years and older presenting for outpatient orthopedic evaluation to a single tertiary pediatric orthopedic institution over a 1-year period was conducted. Demographic information, chief complaint, pain symptomatology, treatment history, primary orthopedic diagnosis, and responses on the Ask Suicide Screening Questionnaire were compared between patients who endorsed suicidality and those that did not.

Results: Of 11,590 individual patient encounters, 201 children (2.0%) endorsed SI with 9 (4.3%) experiencing active and imminent suicidal thoughts. Patients endorsing suicidality were predominantly female (67%), Caucasian (75%), and had a mean age of 14.3 years. Patients who endorsed SI were significantly more likely to present with a chief complaint of pain (46.4% versus 33.3%, p = 0.00008) and ultimately more likely to receive non-structural, non-mechanical pain diagnosis (23.7% versus 16.9%, p = 0.010). Those presenting for pain who screened positive for SI were more likely to characterize their pain as persistent or chronic (81.6%), which trended toward but did not reach statistical significance (p = 0.05). Adjusting for age and sex, multivariate analysis showed that patients taking a psychotropic medication (odds ratio (OR) = 2.45, 95% confidence interval (CI): 1.51–3.84) and carrying a documented preexisting mental health diagnosis (OR = 3.95, 95% CI: 2.85–5.43) were more likely to report SI. Moreover, patients with an underlying mental health disorder presenting with a chief complaint of pain without an identifiable structural or mechanical etiology were 12 times more likely to screen positive for SI (OR = 12.1, 95% CI: 6.36–22.83).

Conclusions: SI is not uncommon among adolescent pediatric orthopedic patients presenting for outpatient care. White females with chronic pain complaints and an existing diagnosis of a mental health disorder appear to be at particularly high risk.

Significance: This is the first comprehensive study to assess SI in a large, outpatient, pediatric orthopedic population over this period. These data suggest that mental health screening and the provision of integrated clinical care with psychologists and other behavioral health specialists may be important to provide comprehensive care to adolescent orthopedic patients.

OP-116

From bytes to bones: assessing the ability of ChatGPT to educate patients and families in pediatric orthopedic surgery

Alex Gornitzky, Raghav Badrinath, Joseph Yellin, Brett R. Lullo

Lurie Children’s Hospital of Chicago, Chicago, IL, USA

LOE-Not Applicable-Level V

Purpose: Generative artificial intelligence (GenAI) applications such as ChatGPT are increasingly being utilized to interpret, summarize, and deliver information across many disciplines. It is imperative that we understand the ability and limitations of GenAI within healthcare. The aim of this study was to assess the level and accuracy of ChatGPT in communicating information about pediatric orthopedic procedures to patients and families.

Methods: We prompted ChatGPT to explain the indications, risks, benefits, and alternatives to five common surgeries: closed reduction percutaneous pinning for supracondylar humerus fractures, flexible intramedullary nailing for femoral shaft fractures, posterior spinal fusion for adolescent idiopathic scoliosis, open hip reduction for developmental hip dysplasia, and physeal-sparing anterior cruciate ligament reconstruction. The unedited responses were distributed to practicing pediatric orthopedists across four academic institutions. Surgeons were asked to rate the author’s level of experience, assess the accuracy and completeness of the information, and determine whether it was sufficient to provide education to families without modification. Respondents were blinded to the fact that the information was written by GenAI.

Results: There were 18 respondents from 4 institutions, with the majority (n = 15; 83%) having ≥11 years of experience. Respondents most attributed the level at which the information was written to that of a fellow (32%) (Figure 1A). However, 35% of respondents felt the information was written by an author at either the junior or senior attending level. There were no differences in perceived level of experience by subsections (indications, risks, benefits, alternatives) (Figure 1B). Overall, respondents felt that the medical information provided was accurate and complete (Figure 1C), with 63% of total explanations receiving a score ≥ 4/5. Across all subsections, 50% of respondents felt the explanations were sufficient to provide education to families without modification (Figure 1D). When answering questions concordant with their own self-selected subspecialty, respondents were equally likely to grade the explanations as accurate and complete (60% with a score ≥ 4/5), but less likely to feel they were sufficient for family consumption without modification (43%).

Conclusions: ChatGPT can provide high-level information about common pediatric orthopedic procedures. However, while most respondents felt the information was accurate and complete, only half felt the information was sufficient to provide education to families without modification.

Significance: As GenAI applications such as ChatGPT become increasingly available, families will utilize them more often to obtain medical information. This study is the first to evaluate the ability of GenAI to communicate accurate information about pediatric orthopedic surgery to patients.

EPOS/POSNA Abstract Book (66)

OP-117

Greater obstetric barriers for female orthopedic surgeons compared to the general population and peer physicians

Emily Reeson, Gwen Grimsby, Melissa Esparza, Heather Menzer

Phoenix Children’s Hospital, Phoenix, AZ, USA

LOE-Not Applicable-Not Applicable

Purpose: Medical training occurs during optimal childbearing years. While unique family planning challenges for surgeons are becoming more widely reported, a gap in knowledge remains regarding fertility and pregnancy risks for each subspecialty. Establishing contemporary trends of infertility risks and pregnancy barriers specific to orthopedic surgeons is imperative to defining steps to improve maternal support at all levels of training and practice. The goal of this study was to determine the prevalence of pregnancy complications, infertility, and maternal support for female orthopedic surgeons in comparison to the general population and other female physicians.

Methods: An anonymous, voluntary survey was distributed to female physicians via private physician social media groups from June to August 2021. The survey queried pregnancy demographics and complications, infertility diagnosis and treatment, workplace environment, and prior education on these topics. Results were compared between orthopedic surgeons and the general population using data from the Centers for Disease Control and Prevention as well as between orthopedic surgeons and other female physicians. Statistical analysis was performed using Fisher’s exact test, chi-square with Yates’ correction, or Student’s t-tests as indicated.

Results: A total of 4638 female physicians completed the survey, including 141 (3%) orthopedic surgeons. Compared with the general population, orthopedic surgeons had children later in life (34.1 versus 23.6 years; p < 0.0001), were more likely to have had a miscarriage (40% versus 19.1%; p < 0.0001), to have undergone infertility evaluation (40.1% versus 8.8%; p < 0.0001) or infertility treatment (31.9% versus 12.7%; p < 0.0001), and to have had a pre-term birth (19.9% versus 10.2%; p < 0.0001). Forty-six percent of orthopedic surgeons reported a pregnancy complication and only 6% received education on risks of delaying pregnancy. Compared to other physicians, orthopedic surgeons were older at first pregnancy (34.1 versus 31.7, p < 0.0001), had fewer children (1.8 versus 2.0, p = 0.0094), were more often discouraged from starting a family during training and practice (56% versus 42%, p = 0.0007), and worked significantly more hours per week while pregnant (59.1 versus 54.1, p = 0.0002; Table 1).

Conclusions: Female orthopedic surgeons have increased risk of miscarriage, infertility, and preterm birth compared to the general population. In addition, orthopedic surgeons experience more negative workplace attitudes and longer working hours while pregnant compared to physician peers. The culture of orthopedic surgery must continue to evolve to better support family planning and childbearing for young physicians during their schooling, training, and early career stages.

Significance: These data will foster steps forward in overcoming the well-described obstetric barriers for orthopedic surgeons in efforts to better support, attract, and retain women in orthopedics.

EPOS/POSNA Abstract Book (67)

OP-118

Full-thickness skin graft versus hyaluronic acid skin graft substitute in syndactyly release: a randomized trial

Ann Van Heest, Deborah Bohn, Jamie N. Price, Susan A. Novotny, Tonye Sylvanus

Gillette Children’s Specialty Healthcare, St. Paul, MN, USA

LOE-Therapeutic-Level II

Purpose: This study assesses scar healing over a 24-month period following syndactyly release surgery using full-thickness autograft (FTSG) versus hyaluronic acid (HA) matrix skin graft substitute. We hypothesized that scar healing would be non-inferior for HA compared with FTSG.

Methods: A randomized, single-blinded, within-subject controlled study was used to compare the effectiveness of HA versus FTSG for 40 webs in 18 patients (aged 1.2 ± 0.8 years) undergoing syndactyly release. HA was used on one side of the web and FTSG was used on the other side of the web in each case. At 12- and 24- month post-surgery scar healing was assessed using Patient and Observer Scar Assessment Scale (POSAS), Vancouver Scar Score (VSS), Web Creep, and the family and surgeon’s preferred scar (FTSG, HA, or equivalent). FTSG source was groin (12 webs) and antecubital fossa (28 webs).

Results: Families rated the syndactyly scar with lower/better scores for FTSG compared to HA at the 12- and 24-month visits. Surgeons’ VSS scores showed preference for FTSG in thickness and vascularity without clear superiority. At the final 24-month visit, FTSG and HA were preferred equally by 42% of families with 16% of families rating HA and FTSG as equivalent; HA was the preferred scar in 46%, FTSG preferred in 31%, and equivalent in 23% according to surgeons. Major complications (CD Level III) occurred in three patients (17%) and included infection, graft failure, and scar revision with return to the OR during the study period.

Conclusions: Neither HA nor FTSG demonstrated superiority as defect coverage for syndactyly release surgery at final follow-up. When compared with FTSG, HA provides diminished surgical time and no donor-site morbidity; however, HA has an open wound for a longer period postoperatively, with greater wound care requirements by families to ensure appropriate wound healing.

Significance: Level of Evidence: II.

EPOS/POSNA Abstract Book (68)

OP-119

Outcomes following operative versus non-operative treatment of completely displaced midshaft clavicle fractures in adolescent baseball players and other overhead athletes

Eric W. Edmonds, David D. Spence, Michael Quinn, Benton E. Heyworth, FACTS Study Group

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level II

Purpose: Recent evidence has demonstrated equivalent or superior outcomes following conservative treatment of completely displaced midshaft clavicle fractures in adolescents. However, specific sub-populations, such as throwers, who may have unique relative benefits from surgical intervention, remain under-investigated. The current study therefore assessed complications and patient-reported outcomes (PROs) in baseball players and other overhead athletes, with specific comparisons of dominant versus non-dominant shoulders and operative versus non-operative treatment.

Methods: Ten 18-year-old patients with completely displaced midshaft clavicle fractures treated at eight participating institutions from 2013 to 2022 were filtered for those who self-reported participation in baseball, softball, racquet sports, water polo, lacrosse, and football quarterbacks. Athletes were divided into operative (open reduction internal fixation (ORIF)) or nonoperative (NonOp) treatment cohorts and sub-divided into dominant versus non-dominant injured laterality. Demographics, fracture characteristics, outcomes, complications, and PROs (ASES, QuickDASH, Marx Shoulder Activity, EQ5D, EQVAS) were analyzed for patients with a minimum of 1-year follow-up.

Results: Out of a total of 788 adolescents with completely displaced clavicle fractures, 238 overhead athletes (30.2%) included 123 baseball players (51.7%, 15.6% overall), fewer of which were the dominant (46, 37.4%) versus non-dominant shoulder (77, 62.6%). Of the 46 dominant baseball player sub-population, 18 (39.1%) were in the ORIF cohort, compared to 28 (60.9%) in the NonOp cohort. When complications, secondary surgeries, or PROs were compared, the only difference was a superior mean QuickDASH score in the NonOp cohort (p = 0.01), a finding that was replicated when treatment groups in the dominant shoulder of all overhead athletes were compared as well (p = 0.04). When dominant versus non-dominant shoulders were analyzed among baseball players, both within ORIF and NonOp cohorts, there were no differences in complications, secondary surgeries, or PROs between sides. Complications in the dominant side of all overhead athletes were rare, including delayed union (2%), symptomatic malunion (1%), and refracture (4%), and were not statistically different between ORIF and Nonop cohorts. Only one case of nonunion (on the non-dominant side of a baseball player) was identified, despite most patients (77%) undergoing non-operative treatment.

Conclusions: Overhead throwers, including baseball players, who sustained completely displaced midshaft clavicle fractures appear to have equivalent, or perhaps superior results from non-operative treatment, when compared to surgical fixation. Outcomes appear similar between the dominant and non-dominant side, regardless of treatment approach.

Significance: Unlike completely displaced midshaft clavicle fractures in adult patients, similar fractures in adolescent overhead athletes are associated with low rates of complications, such as non-union and symptomatic malunion, regardless of treatment approach.

EPOS/POSNA Abstract Book (69)

OP-120

Two-year patient-reported outcomes and graft rupture following ACL reconstruction in skeletally immature athletes: results from the PLUTO (pediatric ACL: understanding treatment options) prospective cohort study

Mininder S. Kocher, Lauren E. Hutchinson, Danielle Cook, Jeffrey Kay, Benton E. Heyworth, PLUTO Study Group

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level II

Purpose: The purpose of this study was to compare patient-reported outcomes (PROs) and graft rupture in a multicenter prospective cohort study of skeletally immature patients who underwent anterior cruciate ligament reconstruction (ACLR) using growth preservation techniques. The hypothesis was that PROs across sub-cohorts would be similar, but anterior cruciate ligament (ACL) graft rupture rates would be higher in the early adolescent/pubescent group than in the pediatric/pre-pubescent group.

Methods: Skeletally immature patients who underwent ACLR by one of 23 PLUTO surgeon-investigators at one of 10 participating academic medical centers across the United States over a 5-year period (2016–2020) were included. Surgical techniques were categorized as one of three different pediatric/prepubescent physeal-sparing techniques (all-epiphyseal, AE; partial transphyseal, PTP; combined intra-articular/extra-articular, extraphyseal using ilitiobial band, ITB) or an early adolescent/pubescent transphyseal (TP) physeal-respecting technique, and by autograft type (hamstring, HS; soft tissue quadriceps, Q; iliotibial band, ITB). Demographics, surgical characteristics, pedi-IKDC scores, and ACL graft rupture (re-tear) rates were analyzed with comparative statistics.

Results: A total of 742 patients (mean age: 12.9 years (SD, 1.9), 62% male) were included. Two-year follow-up pedi-IKDC was available in 553 (74%) patients at a median 24 (interquartile range (IQR), 24.0–26.7) months post-ACLR. The median pedi-IKDC score for the full cohort at 2-year follow-up was 94.6 (range, 21.7–98.9). Median pedi-IKDC was not found to be different across surgical technique groups (p = 0.22, Figure 1) or graft types (p = 0.51) at 2-year follow-up. Of 665 (665/742, 90%) patients with adequate 2-year re-tear data, 48 (7%) experienced a re-tear at a median 16 months post-operatively (IQR, 10–22 months). Significant differences were detected in re-tear across surgical techniques (p = 0.008), with pairwise comparisons revealing higher re-tear in TP (10%) than ITB (3%; p = 0.02). No differences were otherwise detected in re-tear across graft types (p = 0.12). The rates of re-tear were significantly higher in the pubescent group (10%) than in the prepubescent group (3%; p = 0.001).

Conclusions: Among skeletally immature patients undergoing ACLR, pre-pubescent children undergoing physeal-sparing techniques have superior 2-year re-tear rates than pubescent adolescents undergoing transphyseal techniques. The physeal-sparing ITB technique has superior re-tear rates compared to the transphyseal technique, but similar outcomes to other pediatric physeal-sparing (PTP, AE) techniques.

Significance: The frequency of ACLR is increasing at a faster rate in pediatric patients than in any other sub-population. There remains a dearth of prospective comparative studies designed to elucidate the optimal techniques for this active, high-risk sub-population.

EPOS/POSNA Abstract Book (70)

OP-121

Fabrication of a biomimetic 3D-printed scaffold for the treatment of large osteochondral defects in an adolescent porcine model: outcomes at 6 months

Sanjoy Kumar Ghorai, Patrick William Whitlock, Sumit Murab, Anish Gangavaram, Chia-Ying James Lin; Jenna Hall

Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA

LOE-Not Applicable-Not Applicable

Purpose: Repair of large osteochondral (OC) defects represents a significant challenge in pediatric orthopedics and often leads to progressive and early osteoarthritis. Current treatments for large OC defects are limited in their clinical success by the defect size and geometry of the recipient, donor tissue availability, and inferior mechanical properties. Differences in structure, architecture, metabolic activity, timing of bone and cartilage regeneration, and the differing moduli of cartilage and subchondral bone require a comprehensive strategy to regenerate OC tissue. Thus, this study aimed to assess the integration of a novel, biomimetic scaffold, and its concomitant regeneration of OC tissue 6 months after treatment of an OC defect. Our hypothesis was that the regenerated OC tissue would be comparable to OATS autograft.

Methods: The study was approved by the IACUC (IACUC2020-0081). Regeneration of OC tissue within a distal femoral OC defect was studied in an adolescent porcine model (Yucatan minipig) after implantation of a novel, biomimetic scaffold. Polycaprolactone (PCL) scaffolds containing thermally stable polylactic acid (PLA) microspheres encapsulating bioinductive, decellularized cartilage or bone matrix were three-dimensional (3D) printed in a biphasic fashion (DCM+ scaffold). The PLA microspheres containing bone DCM were printed in the “subchondral layer” and PLA microspheres containing cartilage DCM within the “cartilage layer” of the scaffolds, mimicking the hierarchical micro-architecture of OC tissue. To assess and compare OC regeneration and integration, PCL scaffolds containing PLA microspheres without DCM (DCM−) and OATS autografts were included as negative and positive controls, respectively. Six months after implantation, OC regeneration was assessed by micro-computed tomography (CT), magnetic resonance imaging (MRI), and biochemical assays.

Results: Six-month implants showed higher percentage of new bone formation in the outer annulus bone of DCM+ scaffolds as compared to DCM− and OATS (p < 0.05) indicating excellent integration of the DCM+ scaffolds within host tissue (Figure 1). Two-dimensional (2D) Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score by MRI study showed new OC regeneration in DCM+ scaffolds comparable to OATS autografts (Figure 2). Histologic staining showed excellent OC regeneration within the DCM+ scaffolds at least comparable to OATS (Figures 3 and 4).

Conclusions: The biomimetic 3D-printed scaffolds exhibited excellent OC regeneration and scaffold integration at 6 months. The tidemark layer was also maintained. Scoring by histology and MRI was comparable to OATS.

Significance: Biomimetic 3D-printed scaffolds recapitulate normal OC tissue architecture at 6 months post-implantation providing evidence for their further development as an alternative to current treatment strategies for large OC defects in pediatric, adolescent, and young adult patients.

EPOS/POSNA Abstract Book (71)

OP-122

Long-term outcome of nonoperative treatment of Perthes disease—244 hips with a mean follow-up of 48 years

Anders Wensaas, Chiara Blatti, Terje Terjesen, Stefan Huhnstock

Department for Children’s Orthopaedics and Reconstructive Surgery, Division of Orthopedic Surgery, Oslo University Hospital, Oslo, Norway

LOE-Prognostic-Level III

Purpose: In Perthes disease, there is an increased risk of osteoarthritis later in life and thus long-term studies are necessary to analyze the outcome. The purpose of this study was to evaluate the prevalence of total hip arthroplasty (THA) after Perthes disease and to define risk factors for poor outcome.

Methods: Patients were recruited from a search of the radiographic archive at our hospital. Inclusion criteria were patients with nonoperative treatment for Perthes disease and a minimum of 25-year follow-up. The femoral head at the healing stage was classified with the modified Stulberg method (a 3-group classification based on the shape of the femoral head: spherical, ovoid, or flat). Information regarding THA was provided by the Norwegian Arthroplasty Register. Kaplan–Meier survival analysis with conversion to THA as the endpoint was used to find the percentage of hips that had not undergone THA.

Results: A total of 229 patients (244 hips) were included in the study, 184 boys and 45 girls. The mean age at diagnosis was 6.2 years (2.1–13.7 years). Treatment was nonoperative with relief of weight-bearing and/or abduction orthosis. At the healing stage, 105 hips (43%) were classified as spherical, 93 (38%) as ovoid, and 46 (19%) as flat. The mean time from diagnosis to follow-up was 48 years (27–72 years). At follow-up, 47 hips (19%) had undergone THA at a mean patient age of 46 years (22–72 years). Age ≥ 6 years at diagnosis was associated with significantly worse outcome compared with that of age < 6 years; the rate of THA in the two groups were 28% and 10%, respectively (p < 0.001). The frequency of THA was 3% in hips with spherical femoral heads, 25% in hips with ovoid heads, and 46% in hips with flat heads (p < 0.001). Survival analysis showed a mean survival rate of 100% in spherical hips, 99% in ovoid hips, and 98% in flat hips at 20-year follow-up and 99%, 76%, and 48%, respectively, at 50-year follow-up.

Conclusions: After a mean follow-up of 48 years, 19% of non-operatively treated hips with Perthes disease had undergone THA. The negative prognostic factors were age ≥ 6 years at diagnosis and deformed (especially flat) femoral head at skeletal maturity.

Significance: The study demonstrates the long-term outcome of non-operatively treated Perthes disease, which should represent a valuable basis for comparison with other treatment methods.

OP-123

In situ fixation of slipped capital femoral epiphysis carries an over 40% risk for later total hip replacement during a long-term follow-up

Thomas Schlenzka, Joni Serlo, Timo Juhani Viljakka, Kaj Tallroth, Ilkka J. Helenius

Helsinki University Hospital, Helsinki, Finland

LOE-Therapeutic-Level IV

Purpose: The elevated long-term risk for arthrosis after treatment of slipped capital femoral epiphysis (SCFE) has been described. Previous studies have observed the need for later total hip replacement (THR) to range from 12% to 24% during a mean follow-up varying between 16 and 38 years. It is possible that the incidence increases with the patients age due to progression of degenerative changes. To our knowledge, no study has described the risk for THR in a more than 40-year follow-up.

Methods: In this study, 138 patients with 172 affected hips treated with in situ fixation were evaluated retrospectively. Ninety-seven patients (70%) were male (mean age 14.0 years for males and 12.7 years for females at surgery) and 35 patients (25%) had a bilateral disease. The median follow-up time was 49 years (range, 37–64 years). Basic demographics, stability, and surgical details were obtained from patient records, preoperative radiographs (slip angle) were measured, and data on THR was gathered from the National Arthroplasty Register.

Results: The preoperative slip angle averaged 39° (SD, 19°). After a median follow-up of 49 years, 56 (41%) patients had undergone THR of a hip previously fixed in situ for SCFE and 64 (37%) of all affected hips had been replaced. Kaplan–Meier analysis gave a median prosthesis-free postoperative survival of 55 years (95% confidence interval, (CI) = 45–64 years) for the affected hips. In a multivariate analysis, females had a twofold (hazard ratio (HR) = 2.42, 95% CI = 1.16–5.07) risk for THR and a greater preoperative slip angle (HR = 1.03 for every increment of 1°, 95% CI = 1.01–1.05) increased the risk for replacement surgery while patient age at surgery, slip laterality, stability of slip, or diagnostic delay did not have a statistically significant effect on risk of THR.

Conclusions: SCFE treated primarily with in situ fixation may lead to THR in more than 40% of the affected hips, when follow-up reaches 50 years. This risk is approximately 15 times the reported life-time risk in our general population. Female sex and increasing preoperative slip angle significantly predicted higher risk of total hip replacement.

Significance: With a median follow-up time of 49 years, our study group of 138 patients represents one of the largest patient series with very long-term follow-up data.

EPOS/POSNA Abstract Book (72)

OP-124

Mid-term outcomes following vertebral body tethering: a single-center cohort with 5+ years of follow-up

Daniel G. ho*rnschemeyer, Sam Hawkins, Nicole Tweedy, Melanie E. Boeyer

University of Missouri, Columbia, MO, USA

LOE-Therapeutic-Level III

Purpose: Vertebral body tethering (VBT) is a new, non-fusion alternative for adolescent idiopathic scoliosis. To date, there are only several published outcome studies with no more than 2 years of postoperative follow-up and almost no outcome data beyond 2 years. We aimed to fill this gap in the VBT literature by evaluating mid-term outcomes in our first 31 consecutive patients. We hypothesized that (1) the postoperative success would decrease, (2) the surgical revision and suspected broken tether rate would increase, and (3) additional patients would convert to a posterior spinal fusion (PSF).

Methods: We retrospectively assessed additional clinical and radiographic data (mean follow-up: 5.7 ± 0.7) from the original 31 consecutive VBT patients previously included in ho*rnschemeyer et al. (2020). This cohort included patients with various curve patterns (e.g. thoracolumbar only, bilateral). Radiographic measurements included standard deformity measures and skeletal maturity status at latest follow-up. Using the same definition of success (i.e. cobb ≤ 30°; no PSF), we revisited the success rate, revision rate, broken tether rate, and conversion to PSF. To assess differences between the values presented in ho*rnschemeyer et al. and those derived from additional follow-up, we performed a two-sided t-test with an alpha of ≤0.05 indicating statistical significance.

Results: Of our first 31 patients treated with VBT, 29 patients returned for additional follow-up after publication. At 5 years, the success rate dropped to 64% as deformity measures increased and the revision rate increased to 28% following two additional surgical revisions. Four additional suspected broken tethers were identified for a rate of 55%, with only one occurring beyond 4 years. Ninety-three percent of this cohort continues to avoid PSF. We observed an average cobb increase of 4° and 8° in the thoracic and lumbar spine, respectively. Statistically significant progression of both thoracic (p < 0.001) and lumbar curves (p = 0.047) were seen only in Lenke 1B/1C patients where we tethered only the main thoracic curve.

Conclusions: With more than 5 years of follow-up on our VBT cohort, we observed: (1) a decrease in the postoperative success rate due to deformity progression in most subgroups and (2) an increase in the revision and suspected broken tether rate. No additional patients received a PSF.

Significance: With more than 5 years of follow-up, 93% of VBT patients continue to avoid a PSF and 89% exhibited deformities that are ≤40°, which may indicate long-term survivorship.

OP-125

A CNP analog as adjuvant treatment for moderate-to-severe osteogenesis imperfecta in the growing mouse: a pilot study

Jack Mulcrone, Ketsia Seide, Erin Carter, Nancy Pleshko, Cathleen L. Raggio

Hospital for Special Surgery, New York, NY, USA

LOE-Therapeutic-Level I

Purpose: Osteogenesis imperfecta (OI), a heterogeneous type 1 collagenopathy, results in fragile bones. Bisphosphonates reduce fractures and are used to manage moderate-to-severe OI in children. C-type natriuretic peptide (CNP) is produced in the growth plate and positively regulates linear bone growth. This study aims to evaluate whether the addition of CNP analog to standard bisphosphonate (alendronate (ALN)) therapy will reduce fracture incidence, improve growth, increase bone mineral density (BMD), and/or improve bone strength in the growing oim/oim mouse.

Methods: At 2 weeks, growing oim/oim mice (N = 17) were divided into four groups: control mice (N = 8) receiving saline treatment and treated oim/oim (oim) mice receiving weekly ALN along with one of three CNP dosages: 20 µg/kg 5 days/week (20x5) (N = 3), 20 µg/kg 3 days/week (20x3) (N = 3), or 10 µg/kg 3 days/week (10x3) (N = 3). Faxitron images were taken at 2 and 14 weeks (sacrifice) to assess fracture incidence, femoral length, and vertebral height. Microcomputed tomography (micro-CT) was used to assess bone microstructural parameters.

Results: This IACUC-approved study found that the 20x5 group had no new fractures at sacrifice, while the 20x3 and 10x3 groups each had one fracture, and untreated oim mice had an average of 1.57 ± 1.33 fractures. All treatment groups showed increased femoral lengths compared to untreated oim mice (Figure 1), with the 20x5 group showing the greatest increase and the 20x3 and 10x3 groups having similar increases. In addition, all treated groups exhibited increased vertebral height; the 20x5 and 10x3 groups had higher vertebral heights than the 20x3 group but were not different from each other. All three dosage groups showed increased cortical bone tissue mineral density (TMD), cortical BMD, cortical bone thickness, trabecular bone volume fraction (BVF), trabecular TMD, trabecular BMD, and trabecular bone number. All three dosage groups had reduced trabecular bone separation (Figure 2). Due to small sample sizes and variability, these differences are reported qualitatively.

Conclusions: Adjuvant CNP analog treatment increased femoral length and vertebral height without compromising fracture reduction and showed added benefits for both trabecular and cortical bone, which was not observed with bisphosphonates alone. Continued enrollment of oim mice will enhance the significance and help determine the optimal dosage for maximizing these positive bone effects.

Significance: This research project aims to discern the optimal dose of the CNP analog as a promising adjuvant treatment with ALN therapy to reduce fracture incidence and improve bone growth, quality, and strength in pediatric patients suffering from OI.

EPOS/POSNA Abstract Book (73)

OP-126

Bi-lateral and bi-level erector spinae plane block in pediatric idiopathic scoliosis surgery: a randomized, double-blind, controlled trial

Malgorzata Domagalska, Piotr Janusz, Tomssz Reysner, Grzegorz Kowalski, Juliusz Huber, Przemyslaw Daroszewski, Tomasz Kotwicki

University of Medical Sciences, Poznan, Poland

LOE-Therapeutic-Level I

Purpose: This study aimed to compare the effect of ultrasound-guided bi-lateral and bi-level erector spinae plane block (ESPB) on pain scores, opioid requirements, neuromonitoring parameters, and surgery-induced stress response, compared with standard analgesia following posterior spinal correction and fusion surgery for idiopathic scoliosis in children.

Methods: This was a prospective, double-blind, randomized controlled trial. Sixty patients aged 10–18 years and with physical status ASA 1 or 2 were randomized into two groups, each receiving either ESPB (n = 30) or a sham block (n = 30). The primary outcomes were pain scores (Numeric Rating Scale, NRS) within 48 h of posterior spinal surgery. The secondary outcomes were total opioid consumption, intraoperative motor-evoked potentials’ (MEPs) amplitude in µV recorded from the tibialis anterior muscle following transcranial magnetic stimulation at the threshold measured in mA, as well as the surgery-induced stress response as expressed by the neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) at 12- and 24-h post-operation.

Results: The ESPB group had lower NRS scores at all time points (30, 60, 90, 120 min, and 6, 12, 24, and 48 h after surgery), all at p < 0.0001, compared with the control group. Total opioid consumption, incidence of nausea and vomiting, and the need for remifentanil or propofol during surgery were significantly lower in the ESPB group. The MEPs showed higher amplitudes and lower stimulus strengths for evoking the threshold responses in the ESPB group. The surgery-induced stress response indicators (NLR and PLR) were significantly lower in the ESPB group.

Conclusions: ESPB performed in adolescents during idiopathic scoliosis surgery provided more effective analgesia and reduced post-operative opioid requirements. Intra-operatively, ESPB reduced the demand for remifentanil or propofol, thus also reducing the anesthesia influence on MEPs. Post-operatively, ESPB inhibited the stress response as expressed by NLR and PLR ratios.

Significance: The study presents better pain control after spinal correction and fusion surgery for idiopathic scoliosis in children with ultrasound-guided ESPB. Ultrasound-guided ESPB does not affect intraoperative MEP’s amplitude.

OP-127

Local wound infiltration reduces acute postoperative opioid requirements in AIS: a prospective double-blind randomized controlled trial

Craig Munro Birch, Sydney Lee, Kelsey Mikayla Flowers Zachos, Shanika De Silva, Grant Douglas Hogue, Michael T. Hresko, Daniel Hedequist

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level I

Purpose: Local wound infiltration is a non-narcotic method of acute pain management following surgical intervention. This double-blind randomized controlled trial (RCT) aimed to determine the impact of wound infiltration with 0.25% bupivacaine with epinephrine, compared to a placebo of equal volume injectable saline, on pain and opioid consumption during the first 24 h postoperatively in patients with adolescent idiopathic scoliosis (AIS) undergoing posterior spinal fusion (PSF).

Methods: AIS patients, ages 10–17 years old, undergoing PSF were randomized to receive intraoperative wound infiltration with 0.25% bupivacaine + epinephrine (treatment) or saline (placebo). Providers, study staff, and patients were blinded to randomization. Postoperatively, patients rated their pain using an 11-point numeric rating scale, 0 to 10. Inpatient pain scores and opioid administration were extracted from medical records. Opioids were converted to morphine milligram equivalents per kilogram (MME/kg). Four 6-h intervals were created to assess average pain scores and total opioids administered during the first 24 h. Linear mixed models were used to analyze differences between treatment groups in pain scores and opioid consumption over time.

Results: Fifty-six patients were included (mean age = 14.7 years, mean body mass index (BMI) = 21.5): 26 randomized to the treatment group and 30 to placebo. Patients were predominantly female (75%), White (82%), and non-Hispanic (83%). On average, patients in the treatment group had slightly higher preoperative major Cobb angles compared to the placebo group (63° versus 55°). Patients in the treatment group consumed significantly less opioids during the first 24 h, with the placebo group receiving an average estimated 6 MME/kg more compared to the treatment group (Figure B, p = 0.049). Difference at interval 1 was most notable with a 27.7% reduction, average 36.1 MME/kg (placebo) compared to 26.1 MME/kg (treatment). Opioid consumption decreased significantly over time with interval 4 (18–24 h) having estimated mean decrease of 13 MME/kg (p < 0.001) compared to interval 1 (0–6 h). Despite reduced opioid usage, there was no statistically significant difference in pain scores between treatment groups during the 24-h postoperative period. However, pain scores decreased across time for the entire cohort by approximately 1 point per interval (Figure A, p < 0.001).

Conclusions: Local anesthetic injection of 0.25% bupivacaine with epinephrine can effectively decrease postoperative opioid consumption in AIS patients in the first 24 h without compromising pain control.

Significance: This is the first RCT to assess the impact of wound infiltration on postoperative pain following PSF for AIS. The results suggest the potential of incorporating local wound infiltration as standard practice.

EPOS/POSNA Abstract Book (74)

OP-128

Efficacy of a multimodal surgical site injection in pediatric patients with cerebral palsy undergoing hip reconstruction: a randomized controlled trial

Danielle Brown, Christina-Angèle Kaulueloa’ainalani Sun, Daniel McBride, Bailey Young, Vineeta Swaroop, Rachel Mednick Thompson

UCLA, Los Angeles, CA, USA

LOE-Therapeutic-Level I

Purpose: One in four children with cerebral palsy (CP) will undergo orthopedic surgery during their childhood. Despite its ubiquity, postoperative pain control has been poorly studied in this patient population. Moreover, poor pain management has been associated with adverse surgical outcomes. Multimodal analgesic injections have been well studied in the adult population, demonstrating safety and efficacy at reducing postoperative pain and narcotic consumption, but this modality has not been studied in pediatric patients undergoing similarly complex procedures. The objective of this study was to evaluate the efficacy of a multimodal surgical site injection for postoperative pain control following operative management of hip dysplasia in patients with CP.

Methods: After obtaining institutional review board (IRB) approval, a multi-center, randomized double-blind placebo control trial was completed. Patients < 18 years old with a diagnosis of CP who were scheduled for varus derotation osteotomy (VDRO) of the proximal femur were randomized to receive a surgical-site injection with either a combination of ropivacaine (3 mg/kg), epinephrine (0.5 mg), and ketorolac (0.5 mg/kg) (experimental group) or normal saline (control). All included patients had identical post-operative care, including immobilization, physical therapy, and standardized, multi-modal postoperative pain control. Pain scores and narcotic consumption were recorded at regular intervals and compared between groups utilizing two-tailed t-test or a non-parametric Mann–Whitney test for quantitative variables and a Fisher’s exact test for categorical variables.

Results: Thirty-four patients were included, evenly divided between study arms. There were no significant differences in demographic variables, Gross Motor Function Classification System (GMFCS), comorbidities, preoperative radiographic parameters, or concomitant surgeries between groups. Patients in the experimental group required significantly lower narcotic medications at all postoperative time points from post-anesthesia care unit (PACU) until hospital discharge compared to controls (0.41 ± 0.42 versus 1.87 ± 2.05 total morphine mEQ/kg, p = 0.01). Similarly, patients in the experimental group were found to have significantly lower pain scores throughout their hospital stays compared to controls (1.0 ± 0.6 versus 2.4 ± 1.1 mean pain score, p < 0.001). There were no significant differences in operative time, OR time, blood transfusion requirements, or hospital length of stay between groups. There were no adverse medication reactions or injection site complications in either group.

Conclusions: In patients with CP undergoing hip reconstruction, surgical-site injection with a multimodal analgesic combination improves pain control and reduces narcotic consumption in the early postoperative period with no observed adverse effects.

Significance: Local multimodal analgesic injections should be adopted as part of standard multi-modal pain control in this patient population for all osseous surgeries.

EPOS/POSNA Abstract Book (75)

OP-129

Analysis of regenerate bone formation using internal lengthening nails in a large animal model: a pilot study

Christopher A. Iobst, Anirejuoritse Bafor, Aidan Gene Isler, Sara McBride-Gagyi, Kell Sprangel

Nationwide Children’s Hospital, Columbus, OH, USA

LOE-Not Applicable-Not Applicable

Purpose: Internal lengthening nails have become the preferred method of long bone lengthening. As the experience with these nails increases, it is clear they behave differently than traditional external fixators. For example, radiographically, internal lengthening nail regenerate bone formation is visually quite different than traditional external fixator bone. While the biology and mechanics of regenerate bone formation with external fixators has been extensively studied, very little is known about the same basic science of regenerate bone formation with internal lengthening nails. This study is the first to attempt an evaluation of internal lengthening nail regenerate bone formation while simultaneously attempting to develop the first feasible large animal model.

Methods: After obtaining IACUC approval, nine male goats had successful implantation of a tibial internal lengthening nail. The surgical technique and implants were identical to normal human surgery. After a 6-day latency, the goats were lengthened three times at 0.25 mm for a total of 0.75 mm per day. Once 2 cm of lengthening was completed, the animals entered the consolidation phase with necropsy at 4 or 8 weeks. Weekly radiographs during distraction and every 2 weeks during consolidation were obtained. Micro-computed tomography (CT) analysis and histology were also performed on each of the specimens.

Results: Although feasible to insert human internal lengthening nails into the goat tibia, the goat anatomy consistently had a deformity apex in the diaphysis. This required the osteotomy site to be more distal than the typical human scenario. The radiographic timeline of regenerate bone formation visually mimicked the human pattern of progressive outside to inside healing. The micro-CT imaging identified a unique characteristic not previously noted in external fixator lengthenings. A fibrous interzone in the center of the regenerate like external fixation was noted, but there was an additional layer of the same tissue on the nail surface within the regenerate bone. This new finding is called the “fibrous innerzone” (see Figure 1). Histology confirmed healing of the regenerate from the outside to inside with a distinct demarcation between the outer more mature bone and the inner fibro-cartilaginous layer.

Conclusions: This pilot study is the first to demonstrate a feasible large animal model for studying internal lengthening nails. We discovered a unique “fibrous innerzone” not previously identified in external fixator regenerate bone.

Significance: This pilot study confirms that regenerate bone formation and healing appears to occur in a different pattern than external fixator lengthenings and warrants further investigation.

EPOS/POSNA Abstract Book (76)

OP-130

Long-term results of epiphyseal distraction prior to resection (Cañadell’s technique) in 169 patients with metaphyseal pediatric bone sarcomas

Jorge Gómez-Álvarez, José María Lamo-Espinosa, Rocío López, Mikel San-Julián

Clínica Universidad de Navarra, Pamplona, Navarra, Spain

LOE-Therapeutic-Level II

Purpose: Cañadell’s technique consists of a Type I epiphysiolysis performed using continuous distraction (1 mm/day) in the last 10–12 days of neoadjuvant chemotherapy by an external fixator. It is performed, prior to resection, in metaphyseal pediatric bone sarcomas. It was designed to achieve a safe margin due to the ability of the physeal cartilage to be a barrier to tumor spread to the epiphysis, avoiding the need for articular reconstruction, and preserving the growth capacity most of the times.

Methods: We retrospectively reviewed patients who had a metaphyseal pediatric osteosarcoma or Ewing’s sarcoma treated at our institution with Cañadell’s technique between 1984 and 2021 with a minimum 2-year follow-up. Demographic data, metastases at diagnosis, type of reconstruction, functional results according to the Musculoskeletal Tumor Society scale, infection rate, local recurrence, and overall survival were obtained. All outcome data were collected prospectively and compared to patients in whom the epiphysis could not be preserved.

Results: A total of 169 patients with pediatric metaphyseal sarcomas (100 osteosarcomas and 69 Ewing’s sarcomas) were treated in our institution with Cañadell’s technique between 1984 and 2021. We found 74% of disease-free survival in osteosarcoma and 68% in Ewing’s sarcoma at a mean follow-up of 15 years versus 59% in those cases in which the epiphysis could not be preserved (p = 0.03). Also, patients whose epiphyses could not be preserved had more metastases at diagnosis. The global infection rate was 9%, the same as in other tumor operations in which chemotherapy and/or radiotherapy were used. In three cases (1.7%), the distraction occurred unexpectedly through the tumor.

Conclusions: Epiphysiolysis prior to resection of metaphyseal pediatric bone sarcomas provides better clinical outcomes in terms of survival and function than patients in whom the epiphysis could not be preserved.

Significance: This study shows the largest series of patients treated with epiphysiolysis prior to resection (Cañadell’s technique) of metaphyseal pediatric bone sarcomas during the last 40 years.

OP-131

Use of serum biomarkers and cytokines to differentiate septic arthritis, osteomyelitis, and transient synovitis in pediatric and adolescent patients

Nichelle Enata, Kirsten Brouillet, Ling Chen, Kim Quayle, Scott J. Luhmann

Washington University School of Medicine, St Louis, MO, USA

LOE-Diagnostic-Level II

Purpose: Differentiating transient synovitis (TS), osteomyelitis (OM), and septic arthritis (SA) in the pediatric population remains a clinical challenge, often resulting in the use of painful, invasive procedures and advanced imaging, which can delay diagnosis and management. The purpose of this study is to develop a serum-based panel of biomarkers and cytokines to accurately diagnose/differentiate TS, OM, and SA at initial presentation.

Methods: A prospective study was completed over an 8-year period, collecting serum samples at the initial evaluation at a tertiary care children’s hospital in patients with the working diagnosis of a possible musculoskeletal infection. Each sample was analyzed for 103 distinct biomarkers and cytokines using enzyme-linked immunosorbent assay (ELISA) testing. Final diagnoses were classified based on clinical scenario, arthrocentesis results, and post-operative synovial fluid cultures. Linear discriminant analysis was performed to identify limited sets of predictive biomarkers and cytokines to accurately diagnose SA, OM, and TS.

Results: A total of 164 pediatric patients whose working diagnosis included a musculoskeletal infection were identified at a single institution over an 8-year period. Average age of SA patients was 5.2 years (0–11 years) with 68% male. Average age of OM patients was 8.1 years (0–18 years) with 59% male. Average age of TS patients was 5.4 years (0–17 years) with 56% male. Twenty-six biomarkers were identified that demonstrated significant differences between SA, OM, and TS. To differentiate SA and TS, a panel of three biomarkers and cytokines was compiled (COMP, TIMP-1, CTACK), which was able to classify 61/69 cases properly (88% accuracy). To differentiate SA and OM, a separate three-panel combination was compiled (COMP, Fractalikine, EGF), which was able to classify 49/64 cases properly (77% accuracy).

Conclusions: The creation of serum-based biomarker/cytokines panels aimed to improve diagnostic accuracy and decrease delays in management in the diagnostic process, in the pediatric population. This study identified two panels of three serum-based biomarkers/cytokines that can accurately differentiate between SA, OM, and TS at initial presentation. Differentiation between TS and SA was 88% accurate, and OM-SA was 77%.

Significance: Serum-based biomarker/cytokine panels can differentiate TS-SA with 88% accuracy and SA-OM with 77% accuracy.

OP-132

Kicking the can in DDH: the impact of age on outcomes following secondary reconstructive surgery for residual dysplasia

Shamrez Haider, Laura M. Mayfield, Corey Gill, Harry K.W. Kim, Daniel J. Sucato, David A. Podeszwa, William Zachary Morris

Scottish Rite for Children, Dallas, TX, USA

LOE-Therapeutic-Level III

Purpose: Following closed reduction of developmental hip dislocations, residual dysplasia is common with rates of secondary reconstructive surgery approaching 50%–60%. The determination and timing of when to proceed with surgery is difficult as acetabular remodeling occurs gradually over the first years following closed reduction. The purpose of this study was to evaluate how age at secondary reconstructive surgery influences the clinical and radiographic outcomes following pelvic osteotomy for residual dysplasia.

Methods: Following institutional review board (IRB) approval, we retrospectively reviewed all Salter or Pemberton pelvic osteotomies performed for residual dysplasia following index closed reduction at a single institution between 1983 and 2020. Patients with concurrent femoral osteotomy, femoral head deformity on follow-up radiographs, or patients with <2 years radiographic follow-up were excluded. Acetabular index (AI) and migration index (MI) were measured on pre-operative, immediate post-operative, and 2-year follow-up radiographs. Following triradiate cartilage closure, final follow-up (FFU) anterior-posterior pelvis radiographs were measured for lateral center-edge angle (LCEA), Tönnis angle, MI, and lateralization ratio (LR). Univariate and multivariate analyses and spearman’s correlation coefficients were used to evaluate outcomes based on age at the time of surgery. Significance was set at p < 0.05.

Results: Eighty-four hips from 77 patients were included, including 52 Salter osteotomies (62%) and 32 Pemberton osteotomies (38%), with mean age of surgery 5.19 ± 1.57 years. There was no significant difference in markers of acetabular dysplasia at 2 years postop or after triradiate closure between hips treated before or after age 5 (all p > 0.05). A higher-than-expected number of patients (41/84, 49%) across both treatment groups demonstrated residual dysplasia at FFU with LCEA < 25 degrees (Figure). However, there was no difference in the rate of residual dysplasia at triradiate closure between hips treated before or after age 5 (48% versus 51%, p = 0.19). There was a weak negative linear correlation between age at pelvic osteotomy and FFU LCEA (−0.23, p = 0.04) across both treatment groups. However, there was no correlation between age at surgery and Tönnis angle, MI, or LR (all p > 0.05). In addition, age at the time of surgery was not a significant predictor of LCEA on multivariate analysis (p = 0.16).

Conclusions: We demonstrated high rates of residual dysplasia at triradiate closure following closed reduction and subsequent pelvic osteotomy. However, the age at secondary reconstructive surgery for residual dysplasia does not significantly influence the radiographic markers of dysplasia at triradiate closure.

Significance: These findings may guide counseling for families and suggest there is no opportunity cost to short-term continued observation while monitoring for acetabular remodeling.

EPOS/POSNA Abstract Book (77)

OP-133

Late-diagnosed DDH is rare in Finland with universal clinical screening program complemented with selective ultrasonography

Emma Luoto, Jenni Katariina Jalkanen, Ilari Kuitunen, Reijo Sund, Aarno Yrjana Nietosvaara

Kuopio University Hospital, Kuopio, Finland

LOE-Not Applicable-Level IV

Purpose: There is an ongoing debate regarding whether universal ultrasound screening should be used to detect developmental dysplasia of the hip (DDH) in newborn. The aim of our study was to assess the effectiveness of universal clinical screening complemented with selective ultrasound used in our country.

Methods: In Finland, pediatricians examine all newborns’ hips in the maternity hospital, and refer infants with suspected DDH to pediatric orthopedic outpatient clinic for a re-examination at 2 weeks of age. General practitioners conduct hip examinations on all infants at 4–6 weeks, at 4 months and at 1.5 years of age in child welfare clinics and refer the children with suspected DDH expectantly to a pediatric orthopedic service. Hip ultrasound is performed at 8 weeks of age to children with suspected or diagnosed DDH. For this retrospective cohort study, we collected the number of children under the age of 15 years that were given DDH (ICD-10 codes Q65.0-6) as the major diagnosis in three or more visits. The data were obtained from The Finnish Care Register for Health Care (HILMO), which collects ICD-10 codes of every medical appointment. We calculated the annual incidence per 1000 newborns of a given DDH diagnosis between 2002 and 2021. Late detected DDH was defined as children aged between 6 months and 15 years at the initial diagnosis who received invasive treatment.

Results: During the 20-year-long study period, altogether 1,103,269 babies were born (median per year = 57,214, range per year = 45,346–60,694). A total of 6421 children were given DDH as a diagnosis (mean per year = 321, range per year = 193–405), giving a mean calculated incidence of 5.8 per 1000 (95% confidence interval (CI) = 5.7–6.0) newborns. The female-to-male incidence rate of DDH was 4.4 (95% CI, 4.3–4.5). Altogether 120 (0.1 per 1000 newborns (95% CI = 0.09–0.1)) children aged between 6 months and 15 years were treated for DDH, with little yearly variation (0.04–0.2 per 1000 newborns). The incidences of late-detected cases varied between 0.07 and 0.2 per 1000 newborns in the five University Hospital Specific Catchment Areas.

Conclusions: The risk of late diagnosis of DDH leading to invasive treatment was 0.01% in Finland without a universal ultrasound screening program.

Significance: Finland’s universal clinical DDH screening of neonates complemented with selective ultrasonography is effective, resulting in one of the lowest reported nationwide incidences of late diagnosed DDH globally suggesting that universal ultrasound screening is unnecessary in our country.

EPOS/POSNA Abstract Book (78)

OP-134

Navigation versus fluoroscopy for anterior VBT screw placement, analysis of 530 screws with confirmatory 3D imaging

Chunho Chen, Jimmy Daher, A. Noelle Larson, Todd A. Milbrandt, Lawrence L. Haber

Ochsner Hospital for Children, New Orleans, LA, USA

LOE-Therapeutic-Level III

Purpose: Vertebral body tethering (VBT) is used to treat scoliosis in skeletally immature patients. Especially with MIS techniques, screw placement can be challenging, and ramifications of screw malposition are significant. The techniques of intraoperative three-dimensional (3D)-imaging/navigation and fluoroscopic screw placement with confirmatory 3D fluoro spine can possibly reduce the rate of pedicle screw malposition. We compare 3D screw accuracy for anterior VBT screws placed with fluoroscopy/check spin versus computed tomography (CT)-guided navigation.

Methods: Retrospective review of the two experienced VBT centers that routinely used either intraoperative CT-guided navigation or fluoroscopic screw insertion followed by check 3D fluoro scan (similar to CT), prior to cord placement, to confirm the screw positions after MIS surgery for VBT. Twenty-two of 133 patients who underwent CT-guided navigation had a postoperative CT scan. Fifty-five patients underwent fluoroscopic-guided screw insertions followed by intraoperative 3D fluoroscopic scan. Images of screws were assessed for appropriate length (no more than 2.5 mm short or beyond the far cortex) and appropriate placement within the vertebral body. Screw accuracy and rate of intraoperative screw revision rate were evaluated.

Results: A total of 530 screws had axial imaging available, including 385 fluoroscopically guided screws and 145 CT-navigated screws. The rate of ideal length screws (no more than 2.5 mm short or beyond the far cortex) was 125/144 (87%) in navigated group and 356/385 (92%) in the check spin group (p = 0.07), respectively. The mean screw length protruding from the cortex were 0.91 mm in navigated group and 0.62 mm in fluoroscopic group (p = 0.02). Ten out of 380 screws were revised intraoperatively after 3D spinsin, prior to cord placement in the fluoroscopic-guided group while no screw was revised in the navigated group. There were no vascular injuries, neurologic monitoring events, or cerebral spinal fluid leaks in either group.

Conclusions: Both CT navigation and use of a check spin are effective strategies to ensure accurate screw position and length. Fluoroscopic guidance might increase the radiation exposure to the surgeons but gives results while still in the OR, prior to cord placement, so revision of screws is simple and during the initial surgery. It also eliminates the need for an incision for the reference Array.

Significance: This is the first study that analyzes the accuracy of navigated and fluoroscopic VBT screws with confirmatory axial imaging. Both fluoroscopy- and CT-guided navigation have high accuracy in VBT surgery that may help lessen the learning curve and improve safety in VBT surgery.

EPOS/POSNA Abstract Book (79)

OP-135

Growth modulation response in thoracic VBT depends primarily on magnitude of concave vertebral body growth

Craig R. Louer, V. Salil Upasani, Jennifer Hurry, Hui Nian, Christine L. Farnsworth, Peter O. Newton, Stefan Parent, Pediatric Spine Study Group, Ron El-Hawary

Vanderbilt University Medical Center, Nashville, TN, USA

LOE-Therapeutic-Level III

Purpose: There is variability in clinical outcomes with vertebral body tethering (VBT) partly due to a limited understanding of the growth modulation (GM) response. We used the largest sample of patients with three-dimensional (3D) spine reconstructions to characterize the changes in disk and vertebra morphology that accompany GM during the first 2 years following VBT.

Methods: A multicenter registry was used to identify adolescent idiopathic scoliosis (AIS) patients who underwent VBT with ≥2 years of follow-up. Calibrated biplanar X-rays obtained at longitudinal time points (pre-op, post-op, and 2 years) underwent 3D reconstruction and subsequent analysis with custom MATLAB software to obtain precision measurements of apical 3 vertebra and 2 disks. GM was defined as change in instrumented Cobb from post-op to 2 years. Groupings based on GM magnitude were compared to determine which morphological changes are responsible for the GM response.

Results: Fifty patients (mean age: 12.5 ± 1.3 years) were analyzed over mean 27.7 months. GM ranged from 46.9° correction to 28.2° loss of correction. Improvement in instrumented Cobb from post-op to 2 years was positively correlated with concave vertebra height growth (r = 0.57, p < 0.001), 3D spine length growth (r = 0.36, p = 0.008), and decreased convex disk height (r = −0.42, p = 0.002). Fifty-four percent of patients were Neutral Modulators (“NM”; 10°> GM > −10°), 36% were High Modulators (“+M”; GM > 10°), and 10% were Poor Modulators (“−M”; −10°> GM[LC1]°). +M patients experienced an additional 1.6 mm (229% increase) of mean concave vertebra growth during study period compared to the −M group, (2.3 versus 0.7 mm, p = 0.039), while convex vertebra height growth was similar (1.3 versus 1.4 mm, p = 0.91, Figure 1).

Conclusions: The mechanism for initial correction and subsequent GM has been further elucidated. If GM occurs, vertebra body heights increase asymmetrically during the GM phase. A strong GM response is correlated with concave vertebral body growth and overall instrumented spine growth. A poor GM response is associated with increase in convex disk height (suspected tether rupture). Future aims will investigate the patient and technique-specific factors which influence increased growth remodeling.

Significance: This is the largest such study on the growth modulation phenomenon of VBT using 3D reconstructions. VBT induces vertebra remodeling by fostering concave vertebra growth, not by inhibiting convex vertebra growth as often hypothesized.

EPOS/POSNA Abstract Book (80)

OP-136

Spontaneous correction of the thoracic curve in Lenke 5 patients: lumbar vertebral body tether (VBT) versus posterior fusion

Jennifer Marie Bauer, Suken A. Shah, Jaysson T. Brooks, Baron S. Lonner, Amer F. Samdani, Firoz Miyanji, Peter O. Newton, Burt Yaszay, Harms Study Group

Seattle Children’s Hospital, Seattle, WA, USA

LOE-Therapeutic-Level II

Purpose: Vertebral body tethering (VBT) is a non-fusion option for skeletally immature patients with idiopathic scoliosis. As with posterior spinal fusion (PSF), compensatory curves are not commonly included in the construct. Prior studies demonstrated spontaneous correction of the compensatory thoracic curve after selective lumbar fusion, which can guide decision making of instrumented levels. However, no prior studies have examined thoracic curve correction after lumbar VBT. We hypothesize a smaller spontaneous correction of the unoperated thoracic curve from lumbar VBT compared to lumbar fusion because of decreased three-dimensional (3D) correction with VBT.

Methods: Retrospectively compared prospectively collected multicenter cohort study.

Results: Twenty-four VBT and 24 fusion patients were matched 1:1 for upper instrumented vertebra (UIV; T8-11), lowest instrumented vertebra (LIV; L2-3), and thoracic Cobb with no differences between pre-operative thoracic or lumbar curves. Fusion patients were 1.4 years older (p = 0.008). There were no significant differences between VBT and PSF for average pre-op or 2 years post-op major T or L curves, T1 tilt, or coronal balance. VBT had 4° less PJK and 10° less L lordosis at 2 years; PSF had 12 mm better coronal balance (Table 1). Thoracic curves worsened an insignificant amount from first erect to 2 years (2° in VBT, <1° in PSF). Compared to pre-operative flexibility radiographs, 2-year post-op thoracic curves were 6.2° (VBT) and 7.0° (PSF) larger (p = 0.83). There were 7 (24%) reoperations in the VBT group: 2 overcorrections relaxed, 2T adding-on (extended to T by PSF-1, VBT-1), 1 broken tether converted to PSF, and 1 (4%) reoperation in the fusion group (pseudarthrosis/broken screw). No other major complications.

Conclusions: Spontaneous thoracic correction is achieved to a similar degree for lumbar VBT and PSF patients operatively treated for their lumbar curves. There is little change in thoracic curve magnitude over time, and, on average, the correction does not reach the pre-operative flexibility curve measurement. There is a higher rate of revision in VBT patients to achieve these outcomes.

Significance: The uninstrumented thoracic curve spontaneously corrects to a similar degree in either tethered or fused lumbar spines, but to less than on the pre-operative flexibility imaging. This should be considered when deciding on whether to include the thoracic curve in a main lumbar VBT or PSF.

EPOS/POSNA Abstract Book (81)

OP-137

Are outcomes improving for AIS following FDA HDE approval?

Lawrence L. Haber, Melanie E. Boeyer, Daniel G. ho*rnschemeyer, Samantha C. Ahrens, Julia Todderud, Todd A. Milbrandt, Susan Scariano, Nicole Tweedy, A. Noelle Larson

Ochsner Hospital for Children, New Orleans, LA, USA

LOE-Therapeutic-Level III

Purpose: The US Food and Drug Administration (FDA) first approved vertebral body tethering (VBT) for AIS in August 2019. Published data thus far are from cohorts treated prior to approval 9/2019 with off-label products (first-generation data (1G)). We sought to evaluate second-generation outcomes (2G) from three experienced centers using a consecutive series of adolescent idiopathic scoliosis (AIS) patients, within FDA indications, treated with VBT for AIS. We hypothesized that 2G results would be superior to 1G due to the use of an on-label device and instrumentation and experience at these centers.

Methods: Multicenter retrospective review of perioperative and postoperative outcomes following VBT. Patient series were consecutive and from three experienced centers. Inclusion criteria were curves between 35 and 65 degrees, skeletally immature patients, and minimum follow-up (fu) of 2 years.

Results: A total of 92 subjects with 104 treated curves were included. Mean initial Cobb 52 (38–65) with mean fu 28 months (21–43). Mean coronal Cobb angles for the first post op visit (FV), 1- and 2-year time points were 26 (9–46), 21 (0–41), and 24 (3–49). Thirty-three patients > 3-year fu with a mean Cobb of 26 (1–40). At most recent fu 88% < 35 degrees. There was 1 fusion (1%) and 9 additional interventions 10%, including 4 reoperations for overcorrection, 4 surgeries for instrumentation complications, and 1 aspiration for pulmonary effusion. The overall additional intervention rate was 11%. Tether rupture 27%. There were 0 neurologic injuries or infections.

Conclusions: For this series of 92 AIS patients treated with an FDA-approved VBT, 2- to 4-year post op outcomes were improved with only 1% fusion rate and 88% of curves < 35. Complications occurred in 11% of patients, which included four reoperations for overcorrection. Good correction on first erect radiograph appears to be a predictor for success. Compared to historical series, second-generation data show promising improvements in outcomes and decreasing rate of complications/reoperations to the original first-generation cohorts.

Significance: This cohort of 92 patients treated with an FDA-approved VBT for AIS from three experienced centers shows improved outcomes, higher success rates, one fusion, and lower reoperation rates than earlier studies using off-label devices. First erect Cobb is likely a predictor for success. Cord rupture continues to be a concern. Larger cohorts and longer follow-up is critical to fully evaluate VBT for AIS.

OP-138

Outcomes in patients with tether rupture after anterior vertebral tethering (AVT) for adolescent idiopathic scoliosis: the good, the bad, and the ugly

John T. Braun, Sofia Federico, David Lawlor, Brian E. Grottkau

Massachusetts General Hospital for Children, Boston, MA, USA

LOE-Therapeutic-Level III

Purpose: Although multiple studies have reported tether rupture (TR) rates after anterior vertebral tethering (AVT) as high as 50%, none have adequately analyzed the clinical significance of TR and factors that potentially increase the likelihood of revision surgery. We reviewed 264 consecutive adolescent idiopathic scoliosis (AIS) patients after AVT and found 5% with early TR at < 2 years and 18% with late TR at ≥ 2 years. The impact of TR on patients was inconsequential in 62%, consequential in 11%, problematic in 19%, and beneficial in 8%.

Methods: Charts, X-rays, and computed tomography (CT) scans were reviewed for TR in 264 consecutive AIS patients treated with AVT for T and TL/L curves 33°–71°. Early TR occurred < 2 years and late TR ≥ 2 years. TR was further categorized as inconsequential (final curve < 40° and no pain), consequential (curve ≥ 40° or pain), problematic (revision required), or beneficial (improvement of overcorrection).

Results: Of 264 consecutive AIS patients s/p AVT, TR was found in 26 patients with 39 curves (20T/19TL) treated at age 14.6 years and R = 2.5. Curves with TR corrected from 49.8° pre-op to 19.9° post-op but lost 8.3° of correction with TR at 2.3 years settling to 28.2° final at 3.3 years F/U. Early TR was seen in 9/171 (5%) and late TR in 17/93 (18%) patients with 2–10 years F/U. TR was inconsequential in 62% (16/26), consequential in 11% (3/26), problematic in 19% (5/26), and beneficial in 8% (2/26). TR occurrence was more common in TL/L curves (73%) and at L2,3 (92%). All TL/L revisions involved tether replacement only whereas thoracic revision required fusion. Revision surgery was unrelated to curve correction or loss of correction but was related to convex back pain (p < 0.05).

Conclusions: This study demonstrated an early TR rate of 5% and late TR rate of 18% in a large series of patients treated with AVT for AIS over 13 years. While most patients had inconsequential TR (62%), with 8.3° loss of correction, a final curve < 40°, and no pain, several patients had consequential (11%) or problematic TR (19%). These adversely affected patients had a final curve ≥ 40°, or pain, or required revision surgery. Fortunately, a small number of patients (8%) benefited from TR by improvement in an area of impending overcorrection.

Significance: Although TR is common after AVT for AIS, in this large study, we found 62% were inconsequential (curves < 40° with only 8.3° loss of correction and no associated pain). Although 30% of patients had a consequential or problematic TR, 8% were beneficial.

OP-139

Complications in vertebral body tethering: what are the effects on patient-reported outcomes?

Katherine Sborov, Mansi Agarwal, Michael J. Heffernan, Jason Anari, Benjamin D. Roye, Stefan Parent, Firoz Miyanji, Selina Poon

Shriners Hospital for Children, Pasadena, CA, USA

LOE-Not Applicable-Level II

Purpose: Vertebral body tethering (VBT) is designed to modulate spinal growth without the disadvantages of posterior spinal fusion (PSF). VBT has continued to gain popularity for treatment of idiopathic scoliosis (IS); however, complication and reoperation rates have been reported as high as 25%. The purpose of this study is to determine how complications from VBT effect patient quality of life (QOL) up to 3 years after surgery.

Methods: In this retrospective cohort study, all AIS patients who underwent VBT were identified via an analysis of multi-center electronic medical record data from the Pediatric Spine Study Group (PSSG). Patient demographics, surgery dates, complications, Early Onset Scoliosis Questionnaire (EOSQ) scores, and Scoliosis Research Society (SRS) scores were collected. Complications were classified using the modified Clavien-Dindo-Sink (mCDS) system. Analysis of QOL after surgery was determined comparing survey scores of patients with and without any complication over time. Additional analysis was performed comparing patients with no/mild complications (mCDS grade I and II), to those with severe complications (mCDS grade IIIA or above).

Results: The study consisted of 339 surveys from 81 patients with EOSQ data and 293 surveys from 101 patients with SRS data. When comparing patients with a complication to those without a complication, patients with complications had significantly lower total EOSQ scores at 2, 2.5, and 3 years after surgery (p = 0.009, 0.001, and <0.001); however, there was no difference in total SRS scores at any time point. In comparing patients with severe complications to patients with mild complications/no complication, patients with severe complications had significantly worse total EOSQ at 2, 2.5, and 3 years after surgery (p = 0.018, 0.002, and <0.001) and SRS scores at 2, 2.5, and 3 years after surgery (p = 0.040, 0.018, 0.010).

Conclusions: Patients with any complication from VBT had worse EOSQ scores at 2 years after surgery. Severe complications (mCDS > 3) following VBT manifest with decreasing EOSQ-24 and SRS-22 scores over time and became statistically significant at 2 years and beyond. Long-term follow-up will ascertain whether these poorer QOL outcomes persist at time points greater than 3 years. Long-term follow-up will be important following VBT to compare to PSF for improved patient education.

Significance: This is the largest cohort of patient-reported outcomes following VBT and the first to study the impact of complications after VBT on HRQOL. The 2-year postoperative time point is an important turning point in quality of life for patients experiencing complications.

EPOS/POSNA Abstract Book (82)

OP-140

Implementation of the Team Integrated Enhanced Recovery (TIGER) protocol following vertebral body tethering

Daniel G. ho*rnschemeyer, Nicole Tweedy, Melanie E. Boeyer

University of Missouri, Columbia, MO, USA

LOE-Therapeutic-Level III

Purpose: The use of an Enhanced Recovery After Surgery Protocol (ERAS-P) has been shown to improve perioperative and postoperative outcomes in many surgical specialties, including pediatric spine deformities. To our knowledge, no such standardized protocol has been developed for vertebral body tethering (VBT) despite unique challenges given its anterior approach. To fill this gap, we developed a Team Integrated Enhanced Recovery (TIGER) Protocol and assessed its effect on perioperative and postoperative outcomes following VBT.

Methods: We retrospectively compared outcomes from 69 consecutive patients treated with a Main Thoracic Tether who received no protocol (P0; n = 23) to either Version 1 (P1; n = 23) or Version 2 (P2; n = 23) of the TIGER Protocol. P0 included a minimum one-night stay in the intensive care unit (ICU) with no other specific postoperative management strategies. P1 incorporated multimodal analgesia without a planned stay in the ICU. P2 discontinued patient-controlled analgesia (PCA) on postoperative day 1 with early chest tube removal. We assessed (1) Patient-Reported Pain (PRP), Oxycodone a Doses (OD), (4) Chest Tube Duration (CTD), Length of Stay (LOS), and any complications (e.g. readmissions) that occurred within the first 90 days. Differences between P’s were determined using a one-way analysis of variance with an alpha of ≤ 0.05 indicating significance.

Results: We observed a significant decrease in most variables across P0, P1, and P2 (Table 1), with the largest differences being between P0 and P2. We significantly reduced LOS and CTD by 2.1 and 1.9 days, respectively, between P0 and P2. The number of OD increased on postoperative day 1 between P0 and P2 (1.6 versus 3.3 doses) but was followed by a pronounced decrease on postoperative day 3 (4.3 versus 2.3 doses). Likewise, PRP was more than one point lower on postoperative days 2 (3.2 versus 2.1) and 3 (2.8 versus 1.7) between P0 and P2. We observed one complication in P0, two in P1, and two in P2; three complications required additional surgical intervention and two resulted in readmissions.

Conclusions: The TIGER Protocol significantly improved outcomes without a subsequent increase in complications, including readmissions. These data highlight the importance of developing perioperative and postoperative protocols specific to VBT and act as the foundation for the development of similar protocols at other institutions.

Significance: An ERAS-P can be a safe and effective way to improve perioperative and postoperative outcomes related to LOS, CTD, OD, and PRP in patients treated with VBT.

EPOS/POSNA Abstract Book (83)

OP-141

Validation study of MR bone-like image for diagnosis of stress fracture (spondylolysis) in the lumbar spine

Yutaka Kinosh*ta, Toshinori Sakai, Kosuke Sugiura, Jiro Kobayashi, Misaki Okita, Koki Moriyama, Shigeki Ueki, Nozomu Yanaida, Koichi Sairyo

Department of Orthopedics, Institute of Biomedical Sciences, Tokushima University Graduate School, Tokushima, Japan

LOE-Diagnostic-Level III

Purpose: In the medical treatment of stress fracture (spondylolysis) in the lumbar spine, computed tomography (CT) scan has been commonly used to classify the stage of the fracture for the treatment plan. However, compared to adults, children have higher radiosensitivity in each organ and have a longer life expectancy, so their radiation exposure should be reduced. With these situations as a background, we have started using bone-like image (BLI) of magnetic resonance imaging (MRI) in place of plain CT scan recently. The aim of this study was to validate the BLI of each stage of the lumbar spondylolysis compared with CT scans.

Methods: We retrospectively investigated BLIs and CT scans of 92 patients (83 males and 9 females, mean 13.9 ± 2.0 years) with lumbar spondylolysis taken from July 2021 to March 2023. A total of 838 pars interarticularis was examined, and all the date interval between CT and MRI were within 1 month, and each finding was compared. The BLI used in this study was based on a Siemens 3 Tesla volumetric interpolated breath-hold imaging (VIBE). The CT-based staging (early, progressive, terminal) was matched with the BLI-based staging (incomplete fracture line, complete fracture line, and gap of 2 mm or more) due to its characteristics, respectively.

Results: Of the 99 “early-stage fracture,” 88 were interpreted as “incomplete fracture” on BLI (concordance rate: 88.9%). Of the 48 “progressive-stage fracture,” 36 were interpreted as “complete fracture” (concordance rate: 75.0%). And, of the 16 “terminal-stage fracture,” 12 were interpreted as gap (concordance rate: 75.0%). Out of 675 pars interpreted as “no fracture” on BLI, 7 fractures were detected on CT scans. Sensitivity/specificity/accuracy of the BLI in diagnosing fractures compared with CT scans was 88.9/99.3/98.1% in early stage, 75.0/99.0/97.6% in progressive stage, 75.0/99.1/98.7% in terminal stage, and 83.4/97.0/94.4% for all fractures.

Conclusions: Although ability of BLI for staging of lumbar spondylolysis was not completely consistent, it is considered sufficient for use in clinical practice. In the future, this imaging technology may become indispensable for reducing radiation exposure in the medical treatment for children with spinal diseases.

Significance: This study presents MR BLI as a big potential to reduce medical radiation exposure in the medical treatment for many spinal diseases.

OP-142

Treatment and health-related quality of life of acute adolescent spondylolysis: a prospective comparative study with 2-year follow-up

Ella Virkki, Milja Holstila, Terhi Kolari, Markus Lastikka, Sari Inkeri Malmi, Kimmo Mattila, Olli Tapio Pajulo, Ilkka J. Helenius

Turku University Hospital, Turku, Finland

LOE-Therapeutic-Level II

Purpose: Spondylolysis is the most common cause of low back pain in young athletes. The study compares outcomes of acute adolescent spondylolysis treated with a rigid brace or a placebo.

Methods: A prospective, comparative study on clinical, radiographic, and health-related quality of life (HRQoL) outcomes in acute spondylolysis patients treated with a rigid thoracolumbar orthosis (Boston brace) or with a placebo (an elastic lumbar support) was performed. A total of 60 patients were prospectively enrolled. First 14 patients were randomized and the remaining 46 chose treatment method themselves. Treatment time was 4 months and follow-up time was 2 years. HRQoL was measured using a Scoliosis Research Society-24 (SRS-24) outcome questionnaire filled before treatment and at 4-month, 12-month, and 24-month follow-up visits. The primary outcome was the HRQoL at 24 months after treatment and whether treatment type or bony union of the spondylolysis affected it. Secondary outcomes were the bony union rates of spondylolysis with a Boston brace and a placebo, development of spondylolisthesis during follow-up time, and factors predicting development of spondylolisthesis.

Results: Out of 60 patients, 57 were included to analysis. Thirty (30/57) patients were treated with a Boston brace and 27 (27/57) patients with a placebo. The bony union rate of spondylolysis did not differ between study groups (20/30, versus 17/27, respectively, p = 0.789). Five patients (5/47, 95% confidence interval (CI) = 4.6, 22.6%) developed spondylolisthesis during 2-year follow-up time. All spondylolisthesis remained low grade through follow-up time (mean slip = 4.2 mm, range = 1.8–7.4 mm) and none of the patients needed operative intervention for spondylolisthesis. Predictive factors for development of spondylolisthesis besides non-union of the spondylolysis could not be estimated as there were so few patients with spondylolisthesis. The HRQoL was similar in both treatment groups in all domains of the SRS-24 through follow-up time (p > 0.05 for all). Two years after treatment, patients who had bony union of the spondylolysis had higher total SRS-24 score (p = 0.029) and higher satisfaction domain score (p = 0.0003) compared to patients with non-union of the spondylolysis, while other domains remained similar (p > 0.05 for all).

Conclusions: Acute spondylolysis can be treated with only restriction of sports. Bony union of the spondylolysis predicts better HRQoL during 2-year follow-up time.

Significance: Achieving bony union of adolescent spondylolysis is desirable as their HRQoL is higher 2 years after treatment. A brace is not needed for treatment. There is a risk of developing spondylolisthesis if bony union of spondylolysis is not achieved.

EPOS/POSNA Abstract Book (84)

OP-143

Spondylolysis, spondylolisthesis, and associated variables in pediatric patients with osteogenesis imperfecta: follow-up from a 2011 study

Garrett Matthew Gloeb, Brian P. Hasley, Maegen Wallace, Hannah Darland

University of Nebraska Medical Center, Omaha, NE, USA

LOE-Prognostic-Level III

Purpose: Osteogenesis imperfecta (OI) is a genetic disorder that results in bone fragility and fractures. Spondylolysis and spondylolisthesis are common in patients with OI and have been shown to be of higher prevalence than in the otherwise healthy population. Our previous study from 2011 showed a prevalence of spondylolysis of 8.2% and spondylolisthesis of 10.9%. The average age of patient was 6.1 years at the time of study. The purpose of this study was to evaluate these patients 10 years later to better understand this condition over time.

Methods: An institutional review board (IRB)-approved retrospective chart review was performed on the original 110 patients with OI enrolled in the prior study. Radiographic measurements in coronal and sagittal planes were performed with chart review to assess ambulatory status, OI type, and other relevant factors.

Results: A total of 72 patients met the inclusion and exclusion criteria for this study. The average age of patients was 15.8 years, and 44% were Risser 4 or 5. In total, 33% (24/72) of the patients had radiographic evidence of either spondylolysis or spondylolisthesis. Spondylolysis was present in 15.3% of cases (11/72). Spondylolisthesis was present in 18.1% of the cases (13/72): 75% were isthmic and 25% were dysplastic. All spondylolistheses were grade 1. No surgeries were reported for spondylolysis or spondylolisthesis correction. All spondylolysis and spondylolisthesis were noted at L5-S1, other than one case of a concurrent L4-L5 and L5-S1 spondylolysis. Scoliosis was noted in 68% of patients (49/72). Comparing the current study to the original study from 2011, there was no significant difference in ambulatory status (p = 0.17). There was a higher incidence of spondylolysis (p = 0.01), spondylolisthesis (p = 0.03), and either condition combined (p < 0.01) in the current study. Within the current study, comparisons were made between those who had spondylolysis or spondylolisthesis and those who did not. The presence of spondylolisthesis was correlated with higher angles of lumbar lordosis (p = 0.04), but spondylolysis was not associated with lordosis (p = 0.43). There was no correlation between spondylolysis and/or spondylolisthesis with the degree of thoracic kyphosis (p = 0.22, p = 0.35) or the presence of scoliosis (p = 0.58, p = 0.60). Ambulatory status correlated with the presence of isthmic spondylolisthesis only (p = 0.02) and not with dysplastic spondylolisthesis or spondylolysis (p = 0.26).

Conclusions: In our study, the incidence of spondylolysis and spondylolisthesis is notably higher than the 6%–8% incidence rate which has been described in an otherwise healthy population.

Significance: Patients with OI have an increased risk for spondylolysis and spondylolisthesis development.

EPOS/POSNA Abstract Book (85)

OP-144

Is it necessary to extend fusion to L4 when correcting pediatric L5/S1 spondylolisthesis?

Ziming Yao, Xuejun Zhang, Rongxuan Gao, Jiahao Jiao, Dong Guo

Department of Orthopedics, Beijing Children’s Hospital, Capital Medical University, National Center, Beijing China, People’s Republic of China

LOE-Prognostic-Level III

Purpose: Posterior spinal fusion has been widely applied for treatment of L5/S1 spondylolisthesis in children. However, the optimal fusion levels for the surgical treatment of spondylolisthesis have been a subject of controversy. The necessity of fusing L4 remains unclear.

Methods: We retrospectively reviewed 68 children with dysplastic L5/S1 spondylolisthesis who underwent posterior lumbar interbody fusion surgery in two hospitals. Patients were divided into two groups according to the upper instrumented vertebra (Group L4 and Group L5). Data were collected from medical records and radiological images preoperatively and at last follow-up. Radiographic parameters including pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, sagittal vertical axis, slip percentage, SDSG dysplastic lumbosacral angle, Dubousset’s lumbosacral angle, and severity index were measured. Surgery-related data and complication data were also collected. The incidence of complications was compared, including neurologic deficit, adjacent segment instability (ASI), and other complications. ASI was defined as progress of slippage > 3 mm, or posterior opening > 5° in the adjacent segment. The number rating scale (NRS) and Oswestry Disability Index (ODI) scores were used to evaluate the clinical outcome. All patients were followed for at least 2 years.

Results: Among 68 patients, there were 15 patients in Group L4 and 53 in Group L5. Patients involved in the two groups had similar baseline demographic characteristics and radiographic parameters. Post-operative slip percentage and SDSG dysplastic lumbosacral angle were significantly lower in the Group L5 (p < 0.05). No other post-operative radiographic differences were observed between groups. Transient neurologic deficits occurred in one patient in the Group L4 and three in the Group L5 (p > 0.05). There were 13 cases of adjacent segment instability in Group L5, compared with none in Group L4 (24.5% versus 0%, p > 0.05). Out of the 13 patients with ASI, 4 underwent revision surgery due to L4-L5 level instability and clinical symptoms. The other patients remained asymptomatic. NRS and ODI scores at last follow-up were also not significantly different between the two groups. Figure 1 shows a 10-year-old girl with high-grade dysplastic spondylolisthesis who underwent posterior L5-S1 fixation and fusion.

Conclusions: Fusion to L5 could achieve comparable satisfactory results to fixing to L4, albeit with an increased likelihood of ASI. Extending fusion to L4 may not be necessary for most of pediatric L5/S1 spondylolisthesis.

Significance: This article assesses the need for extending fusion to the L4 in pediatric L5/S1 spondylolisthesis correction to provide valuable insights for guiding the selection of fusion level.

EPOS/POSNA Abstract Book (86)

OP-145

Spinal fusion for Scheuermann kyphosis has higher complication and revision rates than spinal fusion for idiopathic scoliosis

Katherine Margaret Krenek, Nicole S. Pham, Marleni Albarran, John Vorhies

Stanford Children’s Health, Palo Alto, CA, USA

LOE-Prognostic-Level III

Purpose: Previous studies have reported variable risks associated with surgical treatment of idiopathic kyphosis (IK) when compared with adolescent idiopathic scoliosis (AIS). Some studies report comparable complication profiles while others suggest IK is higher risk. This study aims to compare 90-day and 1-year complication and reoperation rates from a large administrative database.

Methods: We used ICD-10 and CPT codes to identify patients aged 10–18 who underwent spinal fusion for AIS or IK between 2015 and 2021 in the Truven Marketscan database, which is an administrative claims database representing inpatient and outpatient encounters across the United States. Demographics, surgical variables, and complications for patients with 90-day and 1-year post-operative follow up were analyzed. Multivariable logistic regression modeling was performed to identify factors associated with complications and reoperations.

Results: We identified 3625 operative IK and AIS cases (3406 AIS, 219 IK) with 90-day follow-up. The IK cohort was older (age 15.2 versus 14.3, p < 0.001), had more males (54% versus 25%, p < 0.001), more comorbidities (0.3 versus 0.1, p < 0.001), more Ponte osteotomies (58% versus 40%, p < 0.001), and longer length of stay (4.9 days versus 3.8 days; p < 0.001). The 90-day complication rate was 13.7% in the IK cohort versus 4.8% in the AIS cohort(p < 0.001). Reoperation rate was 12.8% in the IK cohort versus 4.0% in the AIS cohort(p < 0.001). 2401 operative cases (2260 AIS, 141 IK) had 1-year follow-up. The 1-year complication rate was 15.6% in the IK cohort versus 5.4% in the AIS cohort(p < 0.001). The reoperation rate was 13.5% in the IK cohort versus 4.7% in the AIS cohort (p < 0.001). Regression analysis controlling for patient characteristics demonstrated that IK was associated with increased odds of overall complications at 90 days (odds ratio (OR) = 2.59; p < 0.001) and 1 year (OR = 2.61; p < 0.001) an increased odds of reoperation at 90 days (OR = 2.78; p < 0.001) and 1 year (OR = 2.38; p < 0.001) versus AIS. There was no association between 1-year complication or reoperation rates and age, sex, length of stay, geographic region, or Ponte osteotomies.

Conclusions: We used a large administrative database to compare the 90-day and 1-year complication and reoperation rates following spinal fusion for IK and AIS. Patients who undergo surgical treatment of IK have significantly increased risk of complications and reoperations than patients with AIS at 90 days and 1 year.

Significance: These data should be useful to providers to counsel patients about risks, benefits, and expected outcomes of surgical treatment for IK scoliosis.

OP-146

Arthroscopic Bankart repair for anterior glenohumeral instability in 488 adolescents between 2000 and 2020: risk factors for subsequent revision stabilization

Jeffrey Kay, Benton E. Heyworth, Donald S. Bae, Mininder S. Kocher, Matthew D. Milewski, Dennis Kramer

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level III

Purpose: Following arthroscopic Bankart repair (ABR) for anterior glenohumeral instability (GHI), adolescent athletes have higher rates of subsequent recurrent instability (R-GHI) than any other sub-population. Elucidating which adolescents are at highest risk of post-operative R-GHI may optimize surgical decision-making. The purpose of this study was to identify prognostic factors associated with recurrent instability requiring re-operation following ABRs, with particular attention to the number of dislocations sustained prior to the index arthroscopic Bankart procedure.

Methods: Patients 12–21 years old who had undergone ABR for anterior GHI at a pediatric tertiary care hospital between 2000 and 2020 were included. A multivariate Cox proportional hazards model, with percentage of patients with R-GHI undergoing re-operation, was utilized with a time-to-event outcome analysis. The Cox model effects were expressed as the hazard ratio (HR). All tests were two-sided, with alpha of 0.05.

Results: Four hundred and eighty-eight adolescent ABR patients (78% male; mean age: 16.9 ± 1.98 years) were analyzed, with 86 patients (17.6%) undergoing revision stabilization for R-GHI, yielding a cumulative risk of 8.8% at 2 years, 16.5% at 5 years, and 20% at 15 years. Revision stabilization procedures occurred at a mean of 2.6 ± 2.1 years from ABR. Risk factors for revision stabilization included > 1 pre-operative dislocation (2 dislocations: HR = 7.4, p = 0.0003; 3+ dislocations: HR = 10.9, p < 0.0001), presence of a Hill-Sachs lesion (small: HR = 2.5, p = 0.0114; medium-large: HR = 4.2, p = 0.0004), younger age (1-year decrease: HR = 1.2, p = 0.0015), and participation in contact sports (HR = 1.8, p = 0.01). Adolescents with only one pre-operative dislocation had a cumulative incidence of revision stabilization (3.2%), which was significantly lower than those with 2 (24.2%) or 3+ pre-operative dislocations (33.5%).

Conclusions: The number of dislocations prior to index ABR was the strongest risk factor for R-GHI requiring revision stabilization in adolescents with anterior GHI, with two dislocations conferring >sevenfold increased risk compared to a single pre-operative dislocation. Other significant risk factors included the presence of a Hill-Sachs lesion, younger age, and participation in contact sports.

Significance: This large cohort allowed for methodologically rigorous statistical techniques to clarify the precise risk factors, and degree of risk, for developing recurrent GHI following ABR in adolescent athletes, the population who is both at greatest risk for developing GHI and for ultimately experiencing post-operative recurrent GHI.

EPOS/POSNA Abstract Book (87)

OP-147

Length of post-treatment immobilization following medial humeral epicondyle avulsion fracture and return of full range of motion: an interim analysis

Ruth Hendry Jones, Samuel Aaron Beber, Eric W. Edmonds, Benton E. Heyworth, Scott D. McKay, Daryl U.S. Osbahr, Michael Saper, Christopher D. Souder, Matthew D. Ellington, Kevin H. Latz, J. Todd Lawrence, Peter D. Fabricant, Donna M. Pacicca, MEMO Study Group

Hospital for Special Surgery, New York, NY, USA

LOE-Therapeutic-Level II

Purpose: Medial humeral epicondyle fractures account for 12%–20% of pediatric and adolescent elbow fractures. As the return of full range of motion (ROM) is a key recovery outcome in pediatric and adolescent patients, it is critical to identify factors which may decrease the risk of elbow stiffness. The purpose of this study is to investigate the interplay of the following variables and their association(s) with regaining full ROM: association between surgical versus nonoperative treatment, length of immobilization, engagement in formal physical therapy, and length of time between injury and treatment.

Methods: This study was conducted prospectively utilizing data from the Medial Epicondyle Multicenter Outcomes (MEMO) cohort study group. Patients diagnosed with a medial epicondyle fracture between 8 and 18 years old, treated surgically or non-surgically (at the discretion of the treating surgeon), were included if they had at least 1 year of follow-up data. Regaining full ROM as defined by 0°–140° extension, or within 5° of extension or 10° of flexion compared to the contralateral side, total time of immobilization following initiation of treatment, participation in formal physical or operational therapy, and the time from injury to treatment initiation (e.g. surgery or casting) were recorded.

Results: A greater proportion of surgically treated patients (N = 150) regained full ROM compared to nonoperatively treated patients (N = 52) (71% versus 56%, p = 0.05). Immobilization time was statistically significantly shorter in patients who were treated operatively than those treated non-operatively (2.0 ± 1.1 weeks versus 3.0 ± 1.2 weeks, p < 0.001). The time of immobilization for those who regained full ROM was statistically significantly shorter than those who did not regain full ROM (2.1 ± 1.2 weeks versus 2.6 ± 1.1 weeks, p = 0.004). Multivariable regression analysis revealed that immobilization time was an independent predictor of regaining full ROM (b = −0.353, p = 0.02) and each week of prolonged immobilization decreased the chances of regaining full ROM by 35%.

Conclusions: The results illustrated that surgically managed patients, despite typically presenting with greater fracture displacement, had better ROM outcomes with a lower incidence of residual elbow stiffness. This association was mediated by shorter immobilization times resulting in more reliably regaining full ROM.

Significance: Because elbow stiffness is a common and feared negative outcome after medial epicondyle fracture treatment, techniques to minimize immobilization times should be considered. With surgical treatment requiring shorter posttreatment immobilization times, surgery may provide an avenue for consistently superior postoperative ROM outcomes in the treatment of medial epicondyle humerus fractures.

OP-148

Mid-term results of treatment of traumatic knee chondral fractures in adolescents

Alberto Losa Sánchez, Gonzalo Cogolludo Pimentel, Joaquín Nuñez De Armas, Javier Fernandez Jara, Luis Moraleda Novo

Hospital Universitario La Paz, Madrid, Spain

LOE-Therapeutic-Level IV

Purpose: Chondral fractures of the knee are common in adolescents and pre-adolescents because of the weaker interface between the articular cartilage and the subchondral bone. Controversy remains regarding the viability of the fragment, if it is going to heal if we fix it, and if it is going to be mechanically functional in the mid- and long-term. The aim of this work is to report the mid-term radiological (magnetic resonance imaging (MRI)) and clinical (patient-reported outcome measures (PROMs)) results of traumatic chondral lesions of the knee in adolescents that were fixed.

Methods: Thirty-three adolescents and pre-adolescents with a traumatic chondral lesion of the knee were included. Demographic, clinical, and surgical data were collected, including symptoms (pain, blockage, joint effusion), presence of patellar instability, lesion location and size, number of implants, and associated surgical procedures. The detached fragment was fixed through an arthrotomy using bioabsorbable pins (Smartnail, Conmed) (Figure 1). Preoperative and postoperative MRI were analyzed. Patients were asked to fill the Kujala, KOOS, Lysholm, Tegner, and UCLA Activity level questionnaires.

Results: Mean age at the time of trauma 13.5 ± 2.2 years. Average time until MRI was performed 66 ± 79.5 days (median = 24 days). Average time until surgery 103 ± 105 days (median = 64 days). Location was patella (54.5%), lateral femoral condyle (33%), femoral trochlea (9%), and medial femoral condyle (3%). Symptoms at the ER were pain (97%), effusion (51.5%), snapping (33%), and locking (6%). 54.5% reported an episode of patellar dislocation. Physis were open at the time of diagnosis in 85% of the patients. The average follow-up was 5.7 years (SD = 3; 1.5–14), with an average age of 19.4 ± 3.9 years. According to MRI results (average 21 months after surgery), all cases healed with good aspect of the articular cartilage. At the latest follow-up, the mean PROMS results were Kujala 87.3; KOOS 91.8; Lysholm 83.1; Tegner 6; and UCLA Activity Level 7.

Conclusions: Fixation of traumatic chondral injuries of the knee in adolescents or pre-adolescents obtains good clinical and radiological results after a mean follow-up of 5.7 years.

Significance: Due to these good results, we strongly recommend fixing a traumatic chondral injury of the knee in pre-adolescents or adolescents.

EPOS/POSNA Abstract Book (88)

OP-149

Patellar lateralization, absence of hyperlaxity, and the mechanism of injury are associated with osteochondral fracture after first-time acute lateral patellar dislocation in adolescents: an MRI-based evaluation

Servet Igrek, Yavuz Sahbat, Erdem Koc, Aytek Huseyin Celiksoz, Mert Osman Topkar, Okan Aslantürk

Kartal Dr. Lütfi Kırdar City Hospital, İstanbul, Turkey

LOE-Prognostic-Level II

Purpose: Although the risk factors for patellofemoral dislocation are clearly defined, specific risk factors for osteochondral fracture (OCF) after patellar dislocation have not been defined yet. The aim of this study was to determine risk factors for OCF by evaluating patients with and without OCF after first-time acute patellar dislocation (APD).

Methods: This multi-center study was conducted as a retrospective examination of the radiological measurements on the magnetic resonance imaging (MRI) of 306 patients. The patients were divided into the OCF group and non-OCF group, and OCFs were grouped according to whether the fracture was in the patella or femur. Patellar height, patellar lateralization, trochlear morphology, patellofemoral matching, and patella types were evaluated on patient MRIs. The presence of hyperlaxity in the patients was determined according to the Beighton scale score. The injury mechanisms of the patients were grouped as pivot sports (contact or non-contact) injuries, injuries resulting from simple falls or straight running, and injuries during daily activities.

Results: A total of 120 OCFs were detected in 108 (35.2%) patients, of which 96 (80%) were in the patella and 24 (20%) in the femur. The rate of OCF after pivot sports injury was found to be significantly higher than in other injury mechanisms (p = 0.001). The rate of absence of hyperlaxity in cases with OCF was found to be statistically higher (p = 0.001). The measurements of tibial tubercule-trochlear groove (TT-TG), tibial tubercule-posterior cruciate ligament (TT-PCL) distance, and lateral patellar displacement were statistically higher in cases with OCF (p = 0.001). In patients without hyperlaxity, the rate of OCF localization in the patella was significantly higher (p = 0.001). No correlation was found between any other parameters and OCF (p > 0.05). The absence of hyperlaxity, and the measurements of TT-TG distance, TT-PCL distance, and lateral patellar displacement were independent risk factors for the incidence of OCF according to the logistic regression analysis.

Conclusions: The absence of hyperlaxity and patellar lateralization are independent risk factors for the occurrence of OCF after first-time patellar dislocation. Pivot sports injury is a non-independent risk factor for the presence of OCF. In patients without hyperlaxity, the incidence of OCF in the patella is higher than in the femur. These important factors should be considered when evaluating patients and starting their treatment.

Significance: The main findings of the current study were that pivot sports (contact, non-contact) injury, absence of hyperlaxity, and lateralized patella were risk factors for OCF after first-time APD in the adolescent patient group.

EPOS/POSNA Abstract Book (89)

OP-150

Number of patellar dislocation events is associated with increased chondral damage of the trochlea: data from the JUPITER group

Joshua Bram, Emilie Lijesen, Daniel W. Green, Matthew William Veerkamp, Bennett Elihu Propp, Danielle Chipman, Benton E. Heyworth, Jacqueline Munch Brady, Beth Shubin Stein, sh*tal N. Parikh, JUPITER Study Group

Hospital for Special Surgery, New York, NY, USA

LOE-Prognostic-Level III

Purpose: Patellofemoral instability (PFI) is frequently associated with chondral injuries to the patella and trochlea. Although prior studies have demonstrated a link between patellar dislocation and chondral injury, the influence of the number of patellar dislocation events on chondral wear is not established. This study aimed to understand the association between the number of patellar instability events and chondral damage in a large population undergoing patellar stabilization procedures.

Methods: This was a retrospective review of patients undergoing primary PFI procedures from December 2016 to September 2022 in the prospective, multi-center Justifying Patellar Instability Treatment by Results (JUPITER) cohort. Cartilage lesions were classified using the International Cartilage Repair Society (ICRS) classification, where ICRS grades 2–4 are defined as abnormal or severely abnormal. The number of dislocation events was grouped into 1–2, 3–5, and >5 dislocations. Multivariable regressions were used to control for demographic characteristics potentially influencing cartilage wear.

Results: A total of 938 patients at mean age 16.2 ± 3.8 years (61.4% female) were included. Of these, 580 (61.8%) demonstrated a chondral injury. The most commonly affected region was the patella (53.1%), followed by the femoral condyles (15.8%), and trochlea (109, 11.6%). Medial patellofemoral ligament (MPFL) reconstruction was performed in 861 (91.8%) cases. There were no differences in the presence (p = 0.21) or grade (p = 0.72) of patellar chondral lesions based on the dislocation number. Patients with >5 patellar dislocations more frequently had a trochlear chondral lesion (19.8%) than the groups with fewer dislocations (1–2: 8.4%, 3–5: 13.0%, p < 0.001). A greater number of dislocations were also associated with a higher proportion of ICRS grades 2–4 trochlear lesions (>5: 15.3%, 3–5: 11.7%, 1–2: 7.6%, p = 0.009). Combined patellar and trochlear lesions were also higher in the most frequent dislocation group (>5 dislocations: 15.8%, 3–5: 9.9%, 1–2: 6.1%, p < 0.001). In multivariable regression accounting for age, sex, BMI, and dislocation count, a dislocation count >5 was the only variable significantly predictive of the presence of a trochlear chondral lesion (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.36–3.43, p = 0.001).

Conclusions: This study demonstrates that an increased number of patellofemoral dislocation events are associated with more frequent trochlear and combined patellar/trochlear chondral damage with higher injury severity potentially requiring surgical management.

Significance: This is the first, large prospective study to demonstrate that multiple patellar dislocations can result in increased and more severe chondral damage.

EPOS/POSNA Abstract Book (90)

OP-151

Dysplasia worsens over time: trochlear morphologic changes in skeletally immature patients across consecutive magnetic resonance imaging studies

Kevin Jossue Orellana, Julianna Lee, Daniel Yang, David Matthew Kell, Jie C. Nguyen, J. Todd Lawrence, Brendan Williams

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Prognostic-Level III

Purpose: Trochlear dysplasia is the most consistent risk factor for recurrent patellofemoral instability (PFI), but there is limited understanding of how the trochlea develops during growth. The aim of this study is to evaluate serial magnetic resonance imaging (MRI) performed in skeletally immature patients with and without PFI to characterize changes in trochlear anatomy over time. We predict that PFI leads to progressive worsening of trochlear dysplasia over time.

Methods: A retrospective case-control study was conducted on pediatric patients (<18 year old) with and without a diagnosis of PFI who had multiple ipsilateral MRIs of the knee at least 6 months apart. Inclusion criteria were patients with open distal femoral physis at the initial MRI and no intervening surgery between MRIs. All patients with PFI were included, and 30 age-matched patients without PFI were identified for comparison. MRIs were retrospectively reviewed to evaluate trochlear morphology using Dejour and Oswestry-Bristol Classifications (OBC) and to measure sulcus angle (SA), trochlear depth index (TDI), medial condylar trochlear offset (MCTO), and lateral trochlear inclination (LTI). Univariate and bivariate statistics were performed to evaluate differences in morphology between MRIs and between groups.

Results: Ninety-eight PFI patients with an average age of 12.5 ± 2.5 years at initial MRI and 30 non-PFI patients with an average age of 11.6 ± 2.8 years were identified. Among PFI patients, rates of moderate to severe (Dejour B-D, OBC flat or convex) trochlear dysplasia increased from the initial to the most recent imaging (67% vs 88%, p < 0.001), and statistically significantly more dysplastic LTI and SA were observed on follow-up (p < 0.05). Among non-PFI patients, the percentage of patients with normal trochlear morphology increased from 53% to 87% (p < 0.001), and less dysplastic measures of TDI, LTI, and SA were seen on follow-up imaging (p < 0.05). When comparing rates of change, trochlear metrics changed toward a more shallow and dysplastic direction in the PFI cohort and toward a deeper and less dysplastic direction in the non-PFI group.

Conclusions: Skeletally immature patients with untreated PFI have trochlear dysplasia that progressively worsens over time. Conversely, those without PFI have trochlear characteristics that appear to normalize with growth. Future work should seek to determine whether patellar stabilization interventions can impact trochlear morphologic changes.

Significance: This study indicates that during early adolescence, trochlear morphology progressively worsens in patients with PFI but progressively deepens in those without PFI.

EPOS/POSNA Abstract Book (91)

OP-152

The incidence and risk factors for an osteochondral fracture after patellar dislocation

Samir Sharrak, Ali Asma, Marcus A. Shelby, Matthew William Veerkamp, Eric J. Wall, sh*tal N. Parikh

Cincinnati Children’s Medical Center, Cincinnati, OH, USA

LOE-Prognostic-Level III

Purpose: Chondral and osteochondral fracture (OCF) are frequently encountered during patellar dislocation. The incidence of such fractures that may require surgical intervention is not known. It is also not known which patient or anatomic risk factors are related to the occurrence of these fractures. The purpose of our study was to evaluate the incidence of OCF following patellar dislocation and identify the risk factors related to the presence of OCF.

Methods: Using a hospital-based surgery database from 2012 to 2022, patients who underwent medial patellofemoral ligament (MPFL) reconstruction were identified. Two distinct groups were established based on the presence of an OCF. Age, gender, skeletal maturity, BMI, Ehlers-Danlos syndrome (EDS), sports injury, reduction requirement, history of contralateral instability, and first-time vs recurrent ipsilateral patellar dislocation were noted. Trochlear depth, Caton-Deschamps Index, tibial tubercule-trochlear groove (TT-TG) distance, and patellar tilt were calculated on MRI. The independent t-test was used for comparison of continuous variables, and chi-square test was used for comparison of categorical variables.

Results: During the study period, 555 knees in 468 patients had MPFL reconstruction. Of these, 177 knees (31.9%) had contralateral instability. The average age at surgery was 15 (±2.83) years. Of all, 65.4% were female. Two hundred twenty-five (40.5%) were skeletally immature. One hundred twenty-two knees (22%) had first-time dislocation, and 433 knees (78%) had recurrent dislocation. Ninety-eight knees (17.7%) required reduction of patellar dislocation, and 45.8% of dislocation were sports related. One hundred fifty-two knees (27%) had an OCF. Forty-six (30%) OCFs required fixation (33 with screw, 11 with bioabsorbable nail, and 2 combined). The average size of OCF that required fixation was 18 mm (7–31 mm) (Figure 1). The rate of OCF fixation in the first dislocation group was 27%, and in the recurrent instability group, it was 3%. Male gender (p = 0.002, odds ratio [OR] = 1.8) and first-time dislocation (p < 0.01, OR = 14.9) were risk factors for OCF. EDS diagnosis (p = 0.009, OR = 0.46) and contralateral instability (p < 0.01, OR = 3.3) were protective factors for OCF. Patella alta was a protective factor (p = 0.03) for OCF, but trochlear dysplasia, patellar tilt, and TT-TG distance were not.

Conclusions: In this large surgically treated patellar instability cohort, the rate of OCF that had to be addressed was 27%. The average size of OCF that underwent fixation was 18 mm. First-time dislocation in males constituted an at-risk group for presence of OCF. Contralateral instability, EDS, and patella alta were protective factors.

Significance: Knowledge related to the incidence and risk factors related to presence of OCF would help in patient counseling and surgical planning.

EPOS/POSNA Abstract Book (92)

OP-153

Isolated medial patellofemoral ligament reconstruction with and without bony patellar fixation in young patients: a multicenter comparison of three operative techniques

Brendan Williams, David Matthew Kell, Kevin Jossue Orellana, Morgan Batley, Nathan Chaclas, Alexandra Dejneka, Amin Alayleh, Theodore J. Ganley, Neeraj Patel, J. Todd Lawrence

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Therapeutic-Level III

Purpose: Various techniques have been described for medial patellofemoral ligament reconstruction (MPFLR) in the setting of patellofemoral instability (PFI). Most rely on bony patellar-sided fixation, carrying the small but not insignificant risk of iatrogenic patellar fracture as well as implant cost. Alternative soft-tissue patellar-sided fixation options have been described, but comparisons with traditional techniques are limited. The purpose of this study was to compare postoperative complication and risk of recurrent instability among three MPFLR techniques in a multicenter trial with a population of young PFI patients.

Methods: A retrospective comparative study was conducted from 2010 to 2021 at two large tertiary care pediatric hospitals identifying adolescent and young adult patients who underwent isolated MPFLR. Patients were grouped based on patellar fixation: (1) allograft bony patellar fixation (BPF) with suture anchors or interference screws, (2) autograft quadriceps tendon turndown (QTT), and (3) allograft modified basketweave (MBW). The latter two techniques utilize suture-based fixation of the graft to the anterior patellar periosteum. Patient demographics, preoperative imaging measures, postoperative complications, and need for subsequent stabilization surgery were recorded. Treatment groups were compared with univariate testing.

Results: We identified 217 patients undergoing isolated MPFLR (83 BPF, 98 QTT, 36 MBW) who had a mean age of 15.3 ± 2.36 years (8.0–18.9 years) and were predominantly female (60%). All baseline characteristics and preoperative imaging measures were similar between treatment groups (Table 1) except for sex distribution (p = 0.017). At a mean follow-up of 1.62 ± 1.63 years, there was a 6% overall rate of early postoperative complication (BPF 8%, QTT 6%, and MBW 8%) and a 13% rate of persistent subluxation or dislocation (BPF 16%, QTT 10%, and MBW 14%) of which 3.7% (BPF 3.6%, QTT 3.1%, and MBW 5.6%) required revision surgical stabilization. There were no significant differences in the rate of complications or subsequent surgical treatment among treatment groups (p > 0.05).

Conclusions: This large, multicenter cohort of adolescents and young adults undergoing isolated MPFLR identified no significant difference in the rate of complications or persistent instability following surgical reconstruction among the three compared operative techniques. These findings support soft-tissue patellar MPFLR fixation as an acceptable alternative to traditional bony techniques.

Significance: Our findings indicate that soft-tissue patellar fixation techniques demonstrate a comparable risk profile and early outcomes to bony fixation options. Given the risks and costs of bony constructs in the setting of the evolving patellar ossification in skeletally immature patients, pediatric surgeons may safely consider these alternative options for patellar-sided MPFLR fixation.

EPOS/POSNA Abstract Book (93)

OP-154

Higher rate of redislocation and osteoarthritis after proximal realignment procedures vs MPFL reconstruction: a comparative long-term study of patellar instability in adolescents with open physis with mean 9 years of follow-up

Maija Jääskelä, Marja Susanna Perhomaa, Lasse Lempainen, Jaakko Sinikumpu

Pediatric Orthopedics and Traumatology, Oulu University Hospital, Oulu, Finland

LOE-Therapeutic-Level II

Purpose: There has been a change of paradigm toward MPFL reconstruction (MPFLR) in treating patellar instability. Previously, proximal realignment procedures (PRP), such as Madigan and Insall, were usual, supported by the idea that growing bones were not involved. We aimed to compare the long-term results of MPFLR and PRP, particularly the risk of redislocation and the rate of early postoperative osteoarthritis.

Methods: All patients aged <17 years, with open physis (N = 129), who had been treated surgically due to patellar instability in 2005–2019 were preliminary included. Nonresidents and patients treated with procedures other than MPFLR/PRP (e.g. tibial tuberosity transfer, sulcus plasty, medial repair) were excluded. Finally, there were 24 patients with 25 knees, out of 31 eligible ones (81%), who participated in long-term clinical and radiographic follow-up visits after mean 9 (2–18) years postoperatively. Surgery performed was based on treating surgeon’s preference and selected individually for every patient. Redislocation and osteoarthritis in radiographs were the main outcomes. Subjective outcomes were also evaluated.

Results: The overall rate of redislocation was 44% (11/25). It was higher (7/10, 70%) after PRP, compared to MPFLR (4/15, 26.7%, p = 0.027). Osteoarthritis (Kellgren and Lawrence groups (KL) II–IV) in the tibiofemoral joint was found in 4/10 (40%) knees after PRP and none after MPFLR (p = 0.008). The respective numbers of patellofemoral osteoarthritis (KL II–IV) were 4/10 (40%) after PRP and one (6.7%) after MPFLR (p = 0.004). Altogether 2/10 (20%) patients in PRP vs 10/15 (66.7%) in MPFLR groups reported no disabilities in daily activities (p = 0.032). Eight of 10 (80%) in PRP and 4/15 (26.7%) in MPFLR groups, respectively, were unable to participate in any or specific sports at the time of follow-up (p = 0.008). There was no difference in subjective knee-specific recovery measured by IKDC (MPFLR 77.8 (SD 14.9) vs PRP 77.5 (SD 18.4), p = 0.973) or Lysholm Knee Scoring Scale (MPFLR 80.5 (SD 12.9) vs PRP 77.1 (15.2), p = 0.589).

Conclusions: In the long term, a great majority (70%) of the patients treated with PRP suffered from redislocation, which is 2.6-fold higher than the rate for those treated with MPFL (27%). PRPs are associated with high (40%) rate of osteoarthritis, given that the patients were young adults, aged <36 years, at the time of follow-up.

Significance: MPFLR should be the choice of treatment, also in skeletally immature patients.

EPOS/POSNA Abstract Book (94)

OP-155

Suture-based repair with debridement and bone grafting of unstable osteochondritis dissecans of the knee

Crystal Perkins, Anthony Egger, Michael T. Busch, Cliff Clifton Willimon

Children’s Healthcare of Atlanta, Atlanta, GA, USA

LOE-Therapeutic-Level IV

Purpose: Unstable osteochondritis dissecans (OCD) lesions of the knee require treatment of the pathologic subchondral bone as well stabilization of the overlying articular cartilage. The purpose of this study is to describe the surgical technique and early outcomes of OCD debridement, autogenous bone grafting, and suture-based repair of unstable OCD of the knee in pediatric patients.

Methods: A retrospective single-institution study was performed of patients with an unstable OCD of the femoral condyle treated with open debridement, autogenous bone grafting, and suture-based repair between January 2020 and May 2022. Patients were contacted prospectively at the time of the study to complete patient-reported outcome scores (PROs) (pedi-IKDC and HSS Pedi-FABS).

Results: Ten patients, five females and five males, with a mean age of 13.6 years (range 9.0–16.0), were included. OCD location was the medial femoral condyle in eight patients and lateral femoral condyle in two patients. All patients underwent arthrotomy, mobilization of the articular cartilage while maintaining an intact hinge, debridement of fibrinous tissue, and curettage and drilling of the sclerotic bed. Distal femoral autograft was harvested from the ipsilateral femoral metaphysis, morcellated, and compacted into the OCD base. The chondral fragment was then repaired utilizing a suture-bridge construct with Vicryl suture (nine patients) or braided nonabsorbable suture (one patient) loaded through small knotless anchors. Magnetic resonance images (MRIs) were obtained in nine patients to assess healing at a mean of 6 months postoperatively. MRI demonstrated bone graft incorporation, minimal bone edema, and a congruent articular cartilage surface in seven patients (78%). One patient had progressive failure of the repair with a loose body, ultimately requiring conversion to osteochondral allograft transplantation 5 months following repair. A second patient had bone marrow edema on her postoperative MRI and later went on to develop progressive instability with cystic changes resulting in conversion to an osteochondral allograft 2 years after repair. Mean clinical follow-up was 13 months. PROs were obtained in nine patients (90%) at a mean time of 23 months following surgery. Median Pedi-IKDC was 100 and HSS Pedi-FABS was 22. Nine patients participated in sports prior to surgery, and eight (89%) returned to sports following surgery.

Conclusions: OCD debridement with autogenous bone grafting and suture-based repair is a viable single-stage surgical treatment for unstable OCD of the knee.

Significance: This novel surgical treatment for unstable OCDs improves biology at the parent-progeny interface, enhances stability, and maintains the native cartilage without the implant-related complications associated with metal screws or bioabsorbable implants.

OP-156

Osteochondritis dissecans of the femoral condyle and coronal malalignment: an evaluation of the demographics, incidence, and severity of disease

Claire Clark, Benjamin Johnson, Charles Wyatt, Bayley Nicole Selee, Philip Wilson, Henry Bone Ellis

Scottish Rite for Children, Frisco, TX, USA

LOE-Prognostic-Level III

Purpose: Osteochondritis dissecans of the knee (KOCD) is uncommon, often presenting in active, skeletally immature patients. An association between condylar OCD lesion location and lower-extremity coronal plane angular deformity has been established, but the clinical implication is evolving. This study aimed to confirm the high rate of coronal malalignment in KOCD and the variation in demographics, presentation features, and radiologic disease severity between those with and without malalignment.

Methods: Patients enrolled in an institutional prospective cohort on KOCD were reviewed. Patients with more than one KOCD in the same knee or inadequate/missing standing alignment imaging within 3 months of presentation were excluded. Prospectively collected clinical, demographic, and radiographic data were obtained, and standard standing alignment measurements were performed. Comparative analysis was performed between KOCD in each condyle presenting with malalignment compared to those that did not.

Results: A total of 156 patients (187 knees) were included, with a mean age of 12.91 years (range 5.42–18.34), 36.36% female, and 66.3% MFC lesions. Of all skeletally immature condylar KOCD, 39.83% presented with malalignment. Twenty-nine of 124 (23.4%) MFC KOCDs were in varus, with most in grade I (26, 21.0%). Forty-two of 63 (66.7%) LFC KOCDs were in valgus, with 46.0% being grade I, 17.5% grade II, and 3.2% grade III. MFC KOCDs in varus were more likely to be “Black or African American” (p = 0.008), larger (coronal width 16.6 mm vs 14.1 mm, p = 0.008), have a linear fluid signal on MRI (64.3% vs 38.8%; p = 0.019), and undergo surgery (86.2% vs 57.9%; p = 0.007). Similar differences were found in LFC KOCDs in valgus, including larger size (sagittal width 20.79 mm vs 16.37 mm; p = 0.006) and a majority “Black or African American” presentation (91.7%; p = 0.05).

Conclusions: Over 1/3 skeletally immature patients with KOCD may be in coronal malalignment and, thus, candidates for guided growth. Valgus is very common in LFC KOCDs, especially in “Black or African American” patients, and is associated with larger anterior to posterior lesions. MFC KOCDs in varus are commonly larger and more advanced lesions.

Significance: The results of this study are significant because they provide a foundation for various future studies. Further investigation is required to determine whether malalignment is detrimental to KOCD healing rates. The results also open doors for research into whether correcting mechanical axis deviation using guided growth surgery can aid in the healing of KOCD lesions.

OP-157

Osteochondral allograft transplantation for capitellar osteochondritis dissecans: excellent patient-reported outcome scores and high return to sports

Cliff Clifton Willimon, Michael T. Busch, Anthony Egger, Erin Yuder, Jason Kim, Shivangi Choudhary, Crystal Perkins

Children’s Healthcare of Atlanta, Atlanta, GA, USA

LOE-Therapeutic-Level IV

Purpose: Unstable osteochondritis dissecans of the capitellum (OCD-C) treated with loose-body removal and marrow stimulation has historically been associated with suboptimal return to high-demand upper-extremity sports. Fresh osteochondral allograft transplantation (OCAlloT) is an alternative treatment which restores subchondral bone and articular cartilage. The purpose of this study was to evaluate the outcomes of OCAlloT in pediatric patients with unstable OCD-C 10 mm or greater in size.

Methods: A single-center prospective study was performed of consecutive pediatric patients, less than 19 years of age, with unstable OCD-C treated with OCAlloT using pre-cut 10-mm, 12-mm, or 16-mm cores. Imaging was obtained preoperatively to assess OCD characteristics, and postoperatively to assess incorporation of the graft. Patient-reported outcome scores (PROs) were obtained preoperatively and annually following surgery. Minimum follow-up duration was 2 years.

Results: Twenty-six elbows in 24 patients, with a mean age of 13.4 years, met inclusion. The most common primary sport was gymnastics in 11 elbows (42%) and baseball/softball in 7 elbows (27%). Most patients (88%) played at a competitive level. OCD location was central in 17 elbows (65%) and far lateral in 9 elbows (35%). Mean MRI size of the OCD was 11 mm in coronal width, 12 mm in sagittal length, and 6 mm in depth. Most elbows (85%) were treated with a single allograft plug. Median OCA size was 12 mm. There were no infections or arthrofibrosis. Two elbows (8%) had a secondary surgery, both underwent partial synovectomy and chondroplasty at 14 and 16 months following the primary surgery. Postoperative MRIs were obtained in 15 elbows (58%) and had a mean BOGIE (Boston Osteochondral Graft Incorporation in the Elbow) score of 11. Mean follow-up duration was 40 months (range 25–60 months). PROs are listed in Table 1. Twenty-one elbows (81%) had returned to sports at 1 year postoperatively, and all but one patient had returned to sports by 2 years following surgery. Forty-five percent of gymnasts returned to gymnastics, while the remaining pursued different sports. Five of six baseball players (83%) returned to baseball.

Conclusions: OCAlloT as a treatment for OCD-C is associated with low rates of complications, excellent graft incorporation, high elbow function and patient satisfaction, and overall high rates of return to sports at 2 years.

Significance: OCAlloT as a treatment for large unstable OCD-C in athletes playing high-demand upper-extremity sports may be associated with more durable early to midterm outcomes than debridement and marrow stimulation.

EPOS/POSNA Abstract Book (95)

OP-158

Intraarticular deformity after temporary epiphysiodesis around the knee

Bjoern Vogt, Jan Disselkamp, Georg Gosheger, Adrien Frommer, Jan Duedal Rölfing, Gregor Toporowski, Carina Antfang, Robert Roedl, Andrea Laufer

University Hospital Muenster, Muenster, Germany

LOE-Therapeutic-Level III

Purpose: Temporary epiphysiodesis (tED) of the distal femur and proximal tibia is an established procedure for correction of leg length discrepancy (LLD). Moreover, it may be employed bilaterally to reduce excessive height. This study evaluated the effect of tED with two different devices on potential intraarticular deformity and coronal malalignment in individuals between 8 and 16 years of age.

Methods: A retrospective radiological analysis of children who underwent tED either by implantation of RigidTacks (Merete, Berlin, Germany) or eight-Plates (Orthofix, Lewisville, TX, USA) between 2009 and 2021 was performed. The assessment of radiological parameters (femoral notch-intercondylar distance (FNID), width of femoral physis (WFP), tibial roof angle (TRA), femoral floor angle (FFA) (Fig.1), joint line convergence angle (JLCA), mechanical lateral distal femoral angle (mLDFA), medial proximal tibial angle (MPTA), and mean absolute difference (MAD)) was conducted on anteroposterior long-leg standing radiographs prior to implantation and prior to device removal, respectively.

Results: Eighty-six individuals (33 girls, 53 boys) with a mean age of 12.5 ± 1.7 years at the time of surgery were included. In 11 patients, tED was conducted bilaterally by implantation of RigidTacks at the medial and lateral distal femur and proximal tibia, respectively, to reduce excessive predicted height. In 75 patients, tED was carried out unilaterally to correct LLD. According to the origin of the LLD, devices were implanted at the distal femur (n = 18), the proximal tibia (n = 10), or both sites (n = 47) medially and laterally. RigidTacks were used in 38 (51%), and eight-Plates in 37 (49%) of these 75 procedures. The mean postoperative follow-up duration was 3.4 ± 1.9 years. In the RigidTack group, the radiological assessment showed a significant change of the FNID (p = 0.011) after tED. In the eight-Plate group, the WFP (p = 0.021), FNID (p = 0.006), and MAD (p = 0.004) changed significantly; the absolute change of the MAD was 3.6 ± 4.9 mm. These findings correlated with an absolute number of five revision surgeries (four conversions to temporary hemiepiphysiodesis, one correction osteotomy) in the eight-Plate group to correct secondary coronal malalignment. In the RigidTack group, six clinically significant changes of coronal alignment that required revision for conversion to temporary hemiepiphysiodesis were detected.

Conclusions: While secondary coronal deformities were observed in both groups, significant changes in joint morphology were only detected in the eight-Plate group. However, further investigation will have to elucidate if this effect may be attributed to differences in the operation technique and implant positioning and whether these findings are clinically relevant.

Significance: Epiphysiodesis devices should cautiously be applied for tED for length correction, as they may produce significant alterations in coronal alignment and intraarticular deformity.

EPOS/POSNA Abstract Book (96)

OP-159

Removal of the metaphyseal screw from tension band constructs after angular correction with hemiepiphysiodesis has high rates of physeal tethering and subsequent need for implant removal

Timothy Torrez, Senah Stephens, Emily Zhang, Chris Makarewich

Department of Orthopedics, University of Utah, Salt Lake City, UT, USA

LOE-Therapeutic-Level IV

Purpose: Removal of the metaphyseal screw from tension band plate constructs after correction of angular deformity in patients treated with hemiepiphysiodesis has been suggested as an alternative to removing the plate and both screws. While this has the potential benefit of increasing the ease of implant removal and reinsertion in the event of rebound, there is debate in the literature regarding the benefits and risks of leaving the epiphyseal screw and plate in place.

Methods: Patients treated with hemiepiphysiodesis at the distal femur and/or proximal tibia with tension band plate and screws who underwent subsequent removal of the metaphyseal screw after correction were included. Charts and radiographs were reviewed for the need for metaphyseal screw reinsertion, subsequent removal of deep implants, and evidence of physeal tethering. Tethering was defined as progressive overcorrection in the treated bone segment after removal of the metaphyseal screw with the mechanical axis moving one full mechanical axis zone or more.

Results: A total of 215 patients with 387 limbs treated met inclusion criteria. Of those, 175 patients were treated for idiopathic genu valgum while 40 were treated for angular deformities due to other conditions (15 skeletal dysplasia, 8 syndromic, 5 Blount’s disease, 4 multiple hereditary exostoses, 2 focal fibrocartilaginous dysplasia, 2 posttraumatic, 2 congenital femoral deficiency, 1 nonossifying fibroma, 1 endocrine). Among all patients, 59 individuals (27%) underwent replacement of the metaphyseal screw due to need for repeat angular correction. One hundred one patients (47%) required implant removal of the tension band and epiphyseal screw construct previously left in place (74 symptomatic, 7 elective, 20 due to tethering). Overall, there were 44 cases of tethering in 36 patients (17%). Patients with tethering included 23 with idiopathic genu valgum, 4 multiple hereditary exostoses, 3 skeletal dysplasia, 2 posttraumatic, 2 syndromic, 1 congenital femoral deficiency, and 1 endocrine. In cases of tethering, seven patients were treated with observation, 11 with implant removal only, 16 with hemiepiphysiodesis on the opposite side, and 2 with osteotomy.

Conclusions: In patients treated with hemiepiphysiodesis with tension band plate, removal of the metaphyseal screw after correction has high rates of tethering and further surgery for iatrogenic deformity correction and implant removal. This technique is not recommended.

Significance: This is the largest series to date examining removal of the metaphyseal screw from tension band plate constructs. Tethering can occur in patients of many diagnoses and often results in the need for further surgical intervention.

EPOS/POSNA Abstract Book (97)

OP-160

Accuracy of four different methods for estimation of remaining growth and timing of epiphysiodesis

Anne Berg Breen, Harald Steen, Sanyalak Niratisairak, Are Hugo Pripp, Joachim Horn

Oslo University Hospital, Oslo, Norway

LOE-Therapeutic-Level III

Purpose: Calculation of remaining growth in children and the timing of epiphysiodesis in leg length discrepancy (LLD) are commonly done by four main methods: the Green-Anderson (GA) method, the White-Menelaus (WM) method, the Moseley Straight Line Graph (M-SLG) method, and the Multiplier (MP) method. According to available literature, none of the methods have shown superior accuracy or precision than the others.

Methods: From a local Health Register consisting of 415 children with LLD prospectively enrolled during the period 1992–2019, 191 children (aged 10–16 years) treated with surgical closure of the growth plate and follow-up until skeletal maturity were included. The patients had at least two simultaneous leg-length measurements and bone age assessments with the last examination conducted 6 months or less before surgery. We evaluated and compared the accuracy of the four prediction methods by the mean absolute prediction error (mAPE; the difference between predicted and measured leg length at maturity) for the long leg, the short leg, and the LLD, based on chronological age versus bone age and the importance of including the reduced growth rate (inhibition) of the short leg compared to the long leg in the calculations.

Results: The mean LLD preoperatively was 2.80 (standard deviation (SD) 1.23) cm, and at maturity, 1.26 (SD 0.99) cm. The WM method used with bone age was the most accurate method with an mAPE for the short leg of 1.6 (SD 1.3) cm, long leg 1.0 (SD 1.2) cm, and LLD 1.0 (SD 0.8) cm. Pairwise comparison of short leg and LLD according to WM and the other methods was statistically significant, also clinically relevant compared to the MP method. Incorporating the reduced growth rate of the short leg did not improve the accuracy for others compared with the WM method.

Conclusions: The WM method used with bone age is the most accurate method in prediction of remaining growth and the timing of epiphysiodesis in children of ages between 10 and 16 years.

Significance: These findings are of clinical importance for the accurate timing of epiphysiodesis.

OP-161

Does osteotomy level influence consolidation time in tibias treated for limb length discrepancy?

Sandeep Bains, Jeremy Dubin, Larysa Hlukha, John E Herzenberg, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

LOE-Therapeutic-Level III

Purpose: It is not clear if the violation of endosteal blood supply that occurs because of intramedullary canal reaming has a negative effect on the bone regeneration following limb lengthening with magnetic intramedullary lengthening nails (MILNs). Delayed consolidation, as it relates to percentage of the tibial canal reamed, has not yet been assessed in the setting of limb length discrepancy (LLD). To this end, we sought to investigate whether the following factors mediate consolidation: percentage of canal reamed, osteotomy level, age, weight, and nail size.

Methods: This is a retrospective clinical record review of 87 patients who underwent tibial lengthening for LLD between 2014 and 2021, at one institution. The cohort included 109 cases. Degree of canal reamed was calculated as a percentage (diameter of canal after reaming/diameter of canal before reaming × 100) and then classified into three groups (<80%, 80%–120%, and >120%). Osteotomies were stratified by diaphyseal, meta-diaphyseal, and metaphyseal levels.

Results: Our findings demonstrated no statistically significant (p = 0.483) impact on the incidence of delayed consolidation arising from the degree of canal reaming prior to intramedullary nail insertion. Likewise, tibial osteotomy level was not associated with an observable change in consolidation index. Age, weight, and nail size also did not appear to mediate consolidation rate in a clinically relevant manner (p = 0.378, 0.351, 0.142, respectively). The consolidation rate did, however, show a strong negative correlation to the amount of lengthening achieved (p < 0.001).

Conclusions: Consolidation outcomes for our cohort were most affected by the amount of lengthening achieved over the course of treatment. Other variables did not emerge as evident mediators in this regard, including percent of canal reaming prior to nail insertion, osteotomy level, age, weight, and nail size. This result, though perhaps a bit surprising, is nonetheless valuable for its promising utility in clinical decision-making. In addition, this study provides a foundation for subsequent investigation beyond the scope of the tibia and one particular limb treatment facility into the larger world of lengthening goals and the nuances that govern them.

Significance: Delayed tibial consolidation after distraction osteogenesis for LLD presents a challenge for patients and surgeons alike. A comprehensive understanding of the various factors informing treatment is essential to appropriately performing safe, efficacious procedures for LLD, as well as for managing the expectations of patients and their families.

OP-162

Does perioperative ketorolac affect bone healing in pediatric limb lengthening or reconstruction patients?

Christopher A. Iobst, Anirejuoritse Bafor, Danielle Hatfield, Anthony Yassall

Nationwide Children’s Hospital, Columbus, OH, USA

LOE-Therapeutic-Level III

Purpose: Distraction osteogenesis represents an extreme version of bone healing since the body must not only heal the osteoplasty but also produce additional new bone at the same time. Consequently, this biologic situation may be the most sensitive to the potential inhibitory effects of ketorolac on bone healing. To our knowledge, no previous study has assessed the effect of perioperative ketorolac on distraction osteogenesis in pediatric patients.

Methods: After obtaining institutional review board (IRB) approval, a retrospective chart review of all patients younger than 17 years between 2017 and 2020 with an osteoplasty for lengthening or gradual deformity correction was performed. Data reviewed included demographics, surgery details, perioperative pain medications, duration of healing, complications, and length of follow-up. Statistical analysis was performed using Spearman’s rank correlation test.

Results: Seventy-six patients were identified, and each averaged four doses of ketorolac. The deformity correction group consisted of 46 patients. The average age was 13 years, and the average deformity correction was 21°. The average total ketorolac given was 94 mg. At average follow-up of 22 months, there was no correlation between the amount of ketorolac used and the duration of healing (p = 0.82). The lengthening group consisted of 30 patients. The average age was 12 years, and the average lengthening amount was 4.1 cm. The average total ketorolac given was 85 mg. At average follow-up of 21 months, there was no correlation found between the amount of ketorolac used and the duration of healing (p = 0.82).

Conclusions: As a result of the opioid epidemic, orthopedic surgeons are using more nonnarcotic pain medications. There is still a concern in the orthopedic community that the use of nonsteroidal anti-inflammatory drugs (NSAIDs) can affect bone healing in their patients. In our study of pediatric distraction osteogenesis patients, we found no correlation between the total amount of ketorolac used and the duration of healing in either limb lengthening or deformity correction. Since distraction osteogenesis represents a tremendous anabolic load on bone to achieve healing, the fact that our distraction osteogenesis patients did not experience any deleterious effects from ketorolac should be reassuring to the pediatric orthopedic community that perioperative ketorolac use is safe. These results reinforce and expand the previously reported evidence that NSAIDs can be used safely as a nonnarcotic alternative in all pediatric orthopedic settings.

Significance: The results of this study are the first to demonstrate that ketorolac can be administered safely in the perioperative setting for pediatric limb-lengthening and deformity correction patients.

OP-163

Evaluation of physical and mental health in adults who underwent limb-lengthening procedures with circular external fixators during childhood or adolescence

Alessandro Depaoli, Marina Magnani, Agnese Casamenti, Marco Ramella, Giovanni Gallone, Gino Rocca, Giovanni Trisolino

IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy

LOE-Therapeutic-Level IV

Purpose: The use of external fixators (EFs) for limb lengthening is common for treating lower-limb-length discrepancy (LLD) in children and adolescents. Since these patients are underage, the decision to undergo a prolonged treatment course with a nonnegligible prevalence of complications falls on parents. In this study, we evaluated the results of the Short Form 36 (SF-36) questionnaire in adult patients who had undergone lengthening surgery with an EF for LLD during childhood or adolescence.

Methods: An Italian version of the SF-36 questionnaire was administered to a cohort of 50 patients who had undergone limb-lengthening procedures for various causes of LLD using circular EFs. These patients received treatment at an average age of 13.4 years (range 7.0–17.4 years) over the period from 2009 to 2021. On average, the questionnaire was completed approximately 8.5 years after the removal of the last EF (range 1.9–13.5 years). We compared the results of each questionnaire item as well as the physical and mental health summary scales (method by Ware et al.) to normative data for age and gender. Our retrospective analysis encompassed several variables, including demographic characteristics, the underlying etiology of LLD, the age at which surgery was performed, the number of lengthening procedures undertaken, preoperative LLD measurements, the total duration of treatment (TTT), the external fixator index (EFI), and residual heterometry. In addition, we assessed complications using the classification system established by Lascombes et al.

Results: In our study, 16% of patients exhibited Physical Component Summary (PCS) scores that fell more than 1 standard deviation (SD) below the normative data, with 6% scoring more than 2 SD below. In contrast, 84% of patients had Mental Component Summary (MCS) scores lower than 1 SD, and 44% scored lower than 2 SD, underscoring the notable prevalence of mental health issues among patients treated for LLD. We observed a modest correlation between PCS values and residual deformity, whereas MCS values exhibited a slight influence with the number of major complications and the TTT.

Conclusions: Treatment of LLD with a circular EF showed good results for physical function in almost all patients. However, the high prevalence of patients with mental health issues highlighted the need for greater psychological support for children and adolescents undergoing lengthening procedures.

Significance: This study is among the few evaluating the functional and psychological impact in young adults of lengthening procedures for LLD performed during childhood and adolescence.

OP-164

Infection rates and risk factors with magnetic intramedullary lengthening nails

Jeremy Dubin, Sandeep Bains, Connor James Green, Larysa Hlukha, John E Herzenberg, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

LOE-Therapeutic-Level III

Purpose: Surgical site infection (SSI) related to intramedullary lengthening nails (ILNs) can lead to delayed consolidation or loss of limb function, resulting in deleterious effects to a patient’s quality of life. With the increasing utilization of magnetic intramedullary lengthening nails (MILNs) in limb-lengthening procedures, we sought to determine the rate of, and risk factors for, infection associated with these newer devices.

Methods: We reviewed a consecutive series of patients who underwent femoral and/or tibial lengthening with MILNs at a single institution between 2012 and 2020 (n = 420). SSI was classified into two groups according to CDC-NHSN criteria. These were defined as, 1) “superficial incisional” (i.e. occurring within 30 days postoperatively and involving incisional skin and subcutaneous tissue), and 2) “deep incisional” (i.e. occurring 30-365 days postoperatively and involving fascial/muscle layers. Post-operative surveillance time was 12 months. Demographics, health metrics, comorbidities, and limb- and surgery-related factors were assessed as potential risk factors for SSI.

Results: Overall incidence of infection was 3.3% (14/420). Superficial infections occurred in 0.5% (2/420). Deep infection comprised 2.9% (30%, 12/420), of which 75% (9/12) were confirmed osteomyelitis. In those patients who developed SSI, the same limb had a history of prior external fixation in 57% (8/14), while 35.7% (5/14) had previous infection or a history of both. Of these, only one case of infection qualified as superficial. A sub-analysis of all patients with a history of prior external fixation in the same bone, regardless of current infectious presentation, was positively correlated with SSI. No other surgery-related infection risk factors reached statistical significance.

Conclusions: Patients with a history of previous external fixation and/or prior infection in the same bone show an independent association with increased rate of infection recurrence. Other speculated risk factors, such as body mass index (BMI), smoking status, certain comorbidities, and prior procedures or trauma, did not reveal an observable relationship to infectious outcomes, although this does not preclude the necessity for future investigation in expanded cohorts.

Significance: These patients could be considered a high-risk group for developing deep-tissue infection. Potential preventatives include prolonged oral antibiotics after MILN insertion or injection of absorbable antibiotic simultaneous with nail insertion.

OP-165

Are you ready to rumble? Fitbone versus precise nail smackdown for managing limb length discrepancy

Elizabeth W. Hubbard, Alexander Cherkashin, Mikhail Samchukov, David A Podeszwa, John G Birch

Scottish Rite for Children, Dallas, TX, USA

LOE-Therapeutic-Level III

Purpose: Intramedullary devices have become the preferred surgical implants for limb lengthening. Currently, two Food and Drug Administration (FDA)-approved intramedullary lengthening nails are available in the United States. While these devices have been compared to external fixation in terms of efficacy, patient comfort, and likelihood of complications, minimal information is available comparing these implants to one another.

Methods: We reviewed all intramedullary limb-lengthening procedures performed at a single center between 2006 and 2020. Information collected included the underlying diagnosis, history of prior lengthening, discrepancy (LLD) at the time of intramedullary lengthening, implant used, and perioperative complications.

Results: In the 14-year study period, 44 patients underwent intramedullary limb lengthening, 24 with the Fitbone and 20 with the Precise (Table 1). There was no difference between groups with regards to underlying etiology, baseline LLD, or incidence of prior surgery or infection. Fitbone patients were more likely to have undergone prior lengthening with an external fixator (Table 1). Implant-related complications were comparable, although there was a trend toward greater implant-related revision surgeries in Fitbone patients (5 vs 1, p = 0.19). More regenerate problems in Fitbone patients were managed surgically while regenerate problems in Precise patients were managed through modification of the lengthening protocol (p = 0.02). There were greater overall joint-related complications in the Fitbone group (p < 0.063), but almost all Fitbone patients were managed successfully with physical therapy and modification of lengthening, whereas five Precise patients required surgical management for loss of motion and joint subluxation/dislocation.

Conclusions: Results suggest that these are equally effective lengthening devices with similar rates of implant-related complications. However, loss of motion and joint subluxation/dislocation are among the most serious complications of lengthening, and intramedullary implant selection does not impact this risk. That almost all Fitbone patients regained joint stability and motion through nonoperative treatment is a reminder that careful physical examination and analysis of radiographs during lengthening as well as aggressive physical therapy can effectively be used to maintain motion and joint stability in these patients.

Significance: The Fitbone and Precise implants are equally effective at correcting limb length discrepancy with comparable rates of complications and implant-related issues. Regardless of implant choice, all patients need to be monitored closely for loss of motion and joint subluxation during lengthening. Modifying distraction rate, rhythm, and frequency in combination with aggressive physical therapy are effective methods to prevent joint-related complications while lengthening.

EPOS/POSNA Abstract Book (98)

OP-166

Chronic knee pain following infrapatellar/suprapatellar magnetic intramedullary lengthening nails versus external fixators in limb length discrepancy

Larysa Hlukha, Oliver Sax, Kyle Kowalewski, John E Herzenberg, Michael Assayag, Philip McClure

International Center for Limb Lengthening, Baltimore, MD, USA

LOE-Therapeutic-Level IV

Purpose: Magnetic intramedullary lengthening nails (MILNs) via an infrapatellar (IP) or suprapatellar (SP) approach are commonly used in tibial lengthening and deformity correction. Prior to the popularization of these devices, however, gradual deformity correction using external fixation was the norm in limb lengthening. Much of the literature has been concentrated in tibial trauma studies, which have shown MILN via SP to be associated with less knee pain than IP or external fixation. Yet no known research has similarly investigated chronic knee pain and MILNs. We assessed differences in chronic anterior knee pain following tibial lengthening via an IP or SP approach with an MILN versus an external fixator.

Methods: We reviewed 147 tibias (55 MILN/IP, 22 MILN/SP, 71 external fixators) in 124 tibial-lengthening procedures at one institution, from February 2012 to July 2020. All explanted patients with ≥12-month follow-up were included. Knee pain was assessed prior to surgery and then postoperatively at 6 months and 12 months, with both the Lysholm Knee Scoring Scale (LKSS) for functional outcomes and the numeric pain scale (0–10) for subjective pain reporting. Differences in knee pain outcomes were compared across methods, with subgroup analysis of MILN for SP and IP.

Results: Mean LKSS was 96.3 for external fixation and 88.5 for MILN (p = 0.011). In the MILN sub-groups, mean LKSS was 91.7 for IP and 85.3 for SP. The IP group reported a lesser mean pain score (0.6 vs 2.1) at 12 months. Bilateral nail recipients demonstrated no knee pain differences from unilateral. At 12 months, external fixation had better knee functional outcomes.

Conclusions: Tibial lengthening via external fixation was associated with less anterior knee pain and better functional outcomes, as compared with either of the MILN approaches. Within the MILN group, IP surpassed SP, particularly in terms of subjective pain scores.

Significance: The emergence of MILNs has been expected to offer improvements in limb-lengthening outcomes as compared to external fixation. However, MILN usage could bring new clinical challenges, particularly concerning the potential for chronic anterior knee pain and decreased functional knee outcomes postoperatively. We focused on tibial lengthening, but similar investigations into chronic knee pain could be raised in larger patient samples and/or for retrograde MILNs in the femur.

OP-167

Three-dimensional gait analysis and patient-reported outcome measures before and 1 year after femoral derotational osteotomy in adolescents with increased femoral anteversion

Anders Grønseth, Anna Marie Johansson, Terje Terjesen, Joachim Horn

Section for Children’s Orthopedics and Reconstructive Surgery, Division of Orthopedic Surgery, Oslo, Norway

LOE-Therapeutic-Level II

Purpose: Idiopathic increased femoral anteversion (IFA) is a common finding in early childhood, and the condition normalizes spontaneously in most children. Persisting IFA after the age of 12 years may require treatment with femoral derotational osteotomy (FDRO). However, the biomechanical and functional effects of FDRO and the selection of patients who might benefit from treatment remain uncertain. The purpose of our study was to explore the kinematic, clinical, and functional effects of FDRO, by comparing selected parameters preoperatively and 1 year after surgery.

Methods: We performed a single-center prospective cohort study. Patients were recruited after written consent from an ongoing randomized controlled trial on IFA. Inclusion criteria were patient age 10–18 years, symptoms consistent with IFA, and CT-verified AV angle ≥30°. Three-dimensional gait analysis was performed preoperatively and 1 year after surgery. The patient group was compared to a reference group of 31 healthy children. Other outcome measures were clinical hip rotation, AV angle measured by CT, and the subscores Activity of Daily Living (ADL) and Sport on the Knee and Osteoarthritis Outcome Score for children (KOOS-Child).

Results: Twenty-eight FDROs were performed in 18 children (15 females). Mean age at surgery was 13.3 years (10–16). The mean AV angle was 51.4° (35°–67°) preoperatively and 21.1° (3°–39°) postoperatively (p < 0.001). Three-dimensional gait analysis in the transversal plane during stance demonstrated significant changes for hip rotation and foot progression angle. The mean internal hip rotation was 8.3° preoperatively and 0.0° after surgery (p < 0.001). The corresponding values for internal foot progression were 12.4° and 0.2° (p < 0.001). The clinical examination showed an improvement in external hip rotation of 26.9°, from a mean of 11.9° to 38.8°. KOOS-Child showed statistically significant improvements in mean ADL (from 79 to 96 points; p < 0.001) and sports (from 53 to 90 points; p < 0.001).

Conclusions: Three-dimensional gait analysis 1 year after FDRO in adolescents with idiopathic IFA demonstrated significant changes in external hip rotation and foot progression angle. The increase in external hip rotation during gait was less pronounced than the clinical improvement of passive external hip rotation and the CT-measured AV angle. The operation led to significant functional improvement.

Significance: Our findings are of clinical significance and contribute to the decision-making process when evaluating adolescents with idiopathic IFA.

OP-168

Correlation of preoperative simultaneous fibular pseudarthrosis with postoperative ankle valgus risk in congenital tibia pseudarthrosis patients

Ge Yang

Hunan Children’s Hospital, Changsha, People’s Republic of China

LOE-Therapeutic-Level III

Purpose: This study evaluated the correlation of preoperative concurrent fibular pseudarthrosis with the risk of ankle valgus deformity in patients with congenital pseudarthrosis of the tibia (CPT) who underwent successful surgical treatment.

Methods: The children with CPT who were treated at our institution between 1 January 2013 and 31 December 2020 were retrospectively reviewed. The independent variable was preoperative concurrent fibular pseudarthrosis, and the dependent variable was postoperative ankle valgus. Multivariable logistic regression analysis was performed after adjusting for variables that might affect the risk of ankle valgus. Subgroup analyses with stratified multivariable logistic regression models were used to assess this association.

Results: Of the 319 children who underwent successful surgical treatment, 140 (43.89%) developed ankle valgus deformity. Moreover, 104 (50.24%) of 207 patients with preoperative concurrent fibular pseudarthrosis developed an ankle valgus deformity compared with 36 (32.14%) of 112 patients without preoperative concurrent fibular pseudarthrosis (p = 0.002). After adjusting for sex, body mass index, fracture age, age of patient undergoing surgery, surgery method, type 1 neurofibromatosis (NF-1), limb-length discrepancy (LLD), CPT location, and fibular cystic change, patients with concurrent fibular pseudarthrosis presented a higher risk of ankle valgus than those without concurrent fibular pseudarthrosis (odds ratio (OR) 2.326, 95% confidence interval (CI) 1.345–4.022). This risk further increased with CPT location at the distal one-third of the tibia (OR 2.195, 95% CI 1.154–4.175), age <3 years of patient undergoing surgery (OR 2.485, 95% CI 1.188–5.200), LLD < 2 cm (OR 2.478, 95% CI 1.225–5.015), and occurrence of NF-1 disorder (OR 2.836, 95% CI 1.517–5.303).

Conclusions: Our results indicate that patients with CPT and preoperative concurrent fibular pseudarthrosis have a significantly increased risk of ankle valgus compared with those without preoperative concurrent fibular pseudarthrosis, particularly in those with CPT location at the distal third, age < 3 years at surgery, LLD < 2 cm, and NF-1 disorder.

Significance: This study underscores the clinical significance of preoperative concurrent fibular pseudarthrosis in CPT patients undergoing surgical treatment. It reveals a substantial association between this condition and a heightened risk of postoperative ankle valgus deformity. The findings provide critical insights for clinicians, enabling them to identify high-risk patients, particularly those with CPT located at the distal tibia, age under 3 years at surgery, limb-length discrepancy of less than 2 cm, and concurrent NF-1. This knowledge informs treatment decisions, potentially reducing the incidence of ankle valgus for CPT patients.

OP-169

Will my child walk funny? The rotational profile of infants and children with classic bladder exstrophy

Maia Regan, Stefano Cardin, Christopher John DeFrancesco, David B Horn

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Prognostic-Level IV

Purpose: Bladder exstrophy is a rare, complex disorder involving the urinary, reproductive, intestinal, and musculoskeletal system. Skeletal findings in this condition include an externally rotated pelvis and acetabular retroversion. While these findings might be expected to cause out-toeing, there are no published data on the rotational profile of infants and toddlers with classic bladder exstrophy (CBE) to confirm this. This study therefore characterizes the rotational profile and walking age of infants and children with CBE.

Methods: A retrospective database of patients with CBE aged 0–17 years at a tertiary care pediatric hospital from January 2014 to June 2023 was queried for historical, examination, and radiographic findings including rotational profile and age at independent ambulation. Patients with incomplete records and those with a diagnosis of cloacal exstrophy or epispadias were excluded.

Results: A total of 46 patients met the inclusion criteria. Seventeen (37%) were female, and 29 (63%) were male. All had exstrophy repair combined with iliac osteotomies at a median age of 3.5 months. There were 22 (47.6%) posterior osteotomies and 24 (52.4%) anterior osteotomies. Forty-four (95.7%) osteotomies were secured with anterior suture fixation, and two with threaded wires. Patients were immobilized with either a spica cast (n = 41, 89%) or skin traction (n = 5, 11%). Preoperatively, bilateral hip internal and external rotation in extension averaged 43° and 78° degrees, respectively. After surgery, hip internal rotation initially decreased and then increased over time while external rotation decreased over the same time as shown in Figure 1. There was not a statistically significant difference in internal or external rotation between patients who had either anterior or posterior osteotomies (p = 0.354 and 0.088, respectively). At 3 years of age, foot progression angle (n = 21) averaged +8.7° ± 5.48° (range 0°–20°) while thigh foot angle (n = 30) averaged +2.8° ± 4.39° (range 0°–10°). Despite most patients undergoing surgery before age 1, all patients walked independently on time at a mean age of 13 ± 2.4 months (range 11°–18 months).

Conclusions: Infants and children with CBE who undergo early reconstruction walk independently at a normal age. They also have a typical rotational profile even though their underlying pelvic anatomy may predispose them toward an externally rotated gait.

Significance: This is the first study documenting rotational profile and age at ambulation for infants and children with CBE. This study provides pediatric orthopedic surgeons with normative data for CBE and will be a valuable aid when counseling families whose child has CBE.

EPOS/POSNA Abstract Book (99)

OP-170

Development and validation of a diagnostic aid for developmental dysplasia of the hip

Andreas Roposch, Rachel Buckingham, Claudia Maizen, Pranai Buddhdev, Aresh Hashemi-Nejad

Great Ormond Street Hospital for Children, London, UK

LOE-Diagnostic-Level II

Purpose: We previously developed standardized diagnostic criteria for development displacia of the hip (DDH) in a multinational EPOS study. These criteria were then validated in a sample of POSNA members. Our aim was that such criteria would enable nonexperts to evaluate infants for DDH in a manner approaching the practice of orthopedic surgeons, with the potential to improve early diagnosis. In this study, we present the development and validation of a diagnostic aid for DDH based on those criteria.

Methods: We devised a diagnostic aid for use in primary care based on our previously validated diagnostic criteria; this was done in several steps with feedback from target diagnosticians. We performed a diagnostic test study in an enriched sample of target infants. The index test was the diagnostic aid administered by 38 family physicians, who examined 354 six- to eight-week-olds. The reference standard test was the outcome of the infant’s examination in a specialist infant hip clinic. The tests were performed concurrently in a setting mimicking primary care. Blinding was maintained at all levels.

Results: The diagnostic aid resulted in a nine-item binary checklist and a short video. The prevalence of DDH was 23.7% (95% confidence interval (CI) 19.4%, 28.5%); PPV = 58.9% (48.9%, 68.3%); NPV = 91.5% (87.3%, 94.7%), post-test disease likelihood despite negative test = 8.5% (5.3%, 12.7%), sensitivity = 75% (64.4%, 83.8%); specificity = 83.7% (78.7%, 87.9%). Wrongly detected were leg length discrepancies (n = 19), Ortolani (n = 9), Barlow (n = 10), and limited abduction (n = 7). Excluding mild ultrasonic abnormalities from analysis gave a sensitivity of 91.1% and specificity of 83.7%.

Conclusions: The diagnostic aid was easy to use in routine clinical care. It demonstrated face, content, and criterion validity in the hands of family physicians.

Significance: A new diagnostic aid has been developed and validated. It has the potential to enable family physicians or pediatricians to evaluate infants for DDH in a manner approaching the practice of orthopedic surgeons. The aid is currently evaluated in a randomized trial for its effectiveness.

OP-171

Spontaneous recovery in the vast majority of stable dysplastic hips

Wesley Theunissen, Maria Christine Van Der Steen, Arnold T Besselaar, Floris Van Douveren, Jaap J Tolk

Máxima Medical Center, Veldhoven, The Netherlands

LOE-Therapeutic-Level II

Purpose: Worldwide controversy exists on the optimal treatment for stable dysplastic hips: abduction brace treatment or active surveillance by ultrasound imaging. This study aims to investigate the percentage of Graf IIb stable dysplastic hips that recover spontaneously without abduction brace treatment and to determine prognostic factors for spontaneous recovery.

Methods: A prospective cohort study was performed at the Máxima Medical Center (Veldhoven, the Netherlands) between April 2018 and May 2023. Infants aged 90–135 days at the first outpatient clinic visit, diagnosed with Graf IIb hip dysplasia and a primary treatment of active surveillance with ultrasound imaging, were included. Ultrasonographic imaging was repeated after 6 weeks. Spontaneous recovery was defined as an α-angle ≥60 degrees after 6 weeks of active surveillance. In case of an α-angle <60 degrees, abduction brace treatment (Pavlik harness) was initiated. Baseline infant characteristics and ultrasound measurements were used as potential predictor variables for spontaneous recovery in univariate and multivariate logistic regression analyses.

Results: A total of 920 infants with hip dysplasia were part of the prospective cohort. Five-hundred seven infants were diagnosed with Graf IIb and had an initial treatment of 6 weeks of active surveillance. This corresponds with 674 hips, as 167 infants had bilateral DDH. Spontaneous recovery of hip dysplasia was observed in 624 hips (92.6%) and in 468 infants (92.3%). Fifty hips (7.4%) and 39 infants (7.7%) did not recover spontaneously and needed additional abduction brace treatment. Univariate logistic regression analysis showed that a higher α-angle and first-born child were potential predictor variables for spontaneous recovery. In multivariate analysis, none of these parameters were significant predictor variables for spontaneous recovery.

Conclusions: Most of the Graf IIb stable dysplastic hips recover spontaneously in infants aged 90–135 days after 6 weeks of active surveillance. This supports that infants with Graf IIb dysplastic hips do not routinely require therapeutic intervention. Reducing unnecessary abduction brace treatment may relieve the burden for the infant, parents, and healthcare system. Future research should focus on the long-term effects of active surveillance on residual dysplasia and the effect of abduction brace treatment after the age of 135 days.

Significance: Regular abduction brace treatment for all Graf IIb dysplastic hips leads to an overtreatment of 92.6% of these hips. We recommend to initially observe all infants aged 90–135 days with Graf IIb dysplastic hips for 6 weeks before starting abduction brace treatment.

OP-172

Follow-up after successful Pavlik Harness treatment for DDH: is 2 years enough?

Jessica Poppy Jane Larwood, Edward Lindisfarne, Kirsten Elliott, Alexander Aarvold

Southampton General Hospital, Southampton, UK

LOE-Economic-Level II

Purpose: There is a lack of clarity regarding the optimum duration for following up children treated successfully for developmental dysplasia of the hip in a Pavlik harness. The purpose of this study was to examine whether children with normal clinical and radiological findings at 2 years of age ever show deterioration by 5 years of age.

Methods: Data were collected prospectively on all babies treated in Pavlik harness at our institution over an 18-month period, with follow-up to 5 years. Demographic, clinical, and radiological parameters were recorded. Standard anterior-posterior radiographs of both hips were taken at 1, 2, and 5 years of age. A normal hip radiograph was defined as acetabular index (AI) within normal range adjusted for age, symmetrical and adequately sized ossific nuclei, and an International Hip Dysplasia Institute (IHDI) grade of 1; plus, a center-edge angle greater than 20° on the radiograph taken at 5 years of age.

Results: There were 170 hips (in 101 babies) successfully treated with a Pavlik harness and had radiographs available for analysis from three distinct time points of 1, 2, and 5 years of age. Of these, 92% of hips were radiologically normal at 2 years of age, and 100% were radiologically normal at 5 years of age. Every child who had normal radiographs at age 2 years had normal clinical and radiological examination at 5 years, with none having any intervention.

Conclusions: This study supports the notion that, following successful treatment with Pavlik harness, it is safe to discharge at 2 years of age.

Significance: Longer follow-up is not necessary if clinical and radiological parameters are normal at 2 years of age. This new information can help with service planning.

OP-173

Comparable amount of residual dysplasia after active surveillance versus abduction brace treatment

Wesley Theunissen, Jaap J Tolk, Arnold T Besselaar, Floris Van Douveren, Maria Christine Van Der Steen

Máxima Medical Center, Veldhoven, The Netherlands

LOE-Therapeutic-Level II

Purpose: The treatment of developmental dysplasia of the hip varies worldwide. In 2021, the Dutch Orthopedic Society introduced a new national guideline on the treatment of stable hip dysplasia. Instead of abduction brace treatment, this guideline recommends to initially monitor all 3-month-old infants with stable hip dysplasia, called active surveillance. If the hip does not normalize ultrasonographically after 6–12 weeks, abduction brace treatment is started. This study compares the amount of residual dysplasia at 1-year follow-up in Graf IIb dysplastic hips treated with abduction brace versus active surveillance.

Methods: A cohort study was performed at the Máxima Medical Center (Veldhoven, the Netherlands). Infants aged between 90 and 135 days at the first outpatient clinic visit and diagnosed with Graf IIb hip dysplasia were included. We compared patients treated before and after the 2021 DDH guideline introduction. The first group of infants was treated with abduction brace treatment by a Pavlik harness after the first outpatient clinic visit between June 2016 and December 2017. The second group of infants was treated according to the active surveillance protocol between January and December 2021. Pelvic radiographs were routinely performed at 1 year of age. The primary outcome was residual dysplasia, defined as an acetebular index (AI) > 2 SD above the value expected for age, gender, and side as defined by Tönnis.

Results: A total of 86 infants (95 hips) in the abduction brace treatment group and 109 infants (147 hips) in the active surveillance group were included. Residual dysplasia was observed in 9 infants (10.5%) and 10 hips (10.5%) in the abduction brace treatment group and in 14 infants (12.8%) and 17 hips (11.6%) in the active surveillance group. The mean AI was 24.6 ± 4.0° in the group that was immediately treated with a Pavlik harness and 24.7 ± 3.8° in the active surveillance group. No statistically significant difference was observed in residual dysplasia (p = 0.257) and acetabular index (p = 0.218) at 1 year of age between the two different treatment strategies. The difference fell within a previously defined noninferiority margin of 10%.

Conclusions: This study shows that infants with Graf IIb stable dysplastic hips can safely be treated by active surveillance. At 1-year follow-up, the amount of residual dysplasia and mean AI is comparable between the group that received abduction brace treatment and the group that received active surveillance.

Significance: Active surveillance is a viable and safe treatment for Graf IIb stable dysplastic hips based on the 1-year follow-up results.

OP-174

Influence of standardized hip ultrasound protocol in Pavlik harness during management of developmental hip dislocation

Carlos David Pargas Colina, Todd Blumberg, Caleb Allred, Apeksha Gupta

Seattle Children’s Hospital, Seattle, WA, USA

LOE-Therapeutic-Level IV

Purpose: Infant hip dislocations benefit from early detection and treatment for optimal outcomes. Prior studies have identified wide variability in the success rate of bracing between institutions. While there are standardized methods to screen infants for hip dysplasia, there are no clear guidelines regarding how to image a child being treated for a hip dislocation with a Pavlik harness. As a result, there is substantial variability in how treatment success or failure is monitored between and within institutions. The purpose of this study was to determine if a standardized in-harness imaging protocol improves outcomes and the likelihood of successful treatment for dislocated hips being treated with the Pavlik harness.

Methods: All patients with hip dislocations and pretreatment ultrasound (US) were included from July 2018 to July 2022. A new institutional US protocol was implemented in July 2020, during which standardized in-harness imaging was obtained for patients with hip dislocations. Patients treated before the implementation of standardized in-harness imaging were categorized as non-standardized and after implementation as a standardized group. Outcomes were compared between standardized and non-standardized groups. A p value < 0.05 determined the significance.

Results: One hundred twenty-eight hips met inclusion criteria (n = 97 patients). The mean age at diagnosis was 41.6 ± 23.4 days and was predominantly female (85.6%). There was no significant difference between the patients’ demographics and baseline clinical characteristics between the standardized and nonstandardized groups. Pavlik’s harness success rate was significantly higher in the standardized group (85% vs 63%, p = 0.0058). Twenty-eight hips in the nonstandardized group remained dislocated. They were indicated for surgical treatment, while only eight hips remained dislocated in the standardized group and necessitated closed or open reduction.

Conclusions: These data suggest standardization of imaging for patients with hip dislocations undergoing Pavlik harness treatment may significantly improve the Pavlik harness success rate.

Significance: The study included 128 hips from 97 patients over a 4-year period, implementing standardized imaging in July 2020. The results showed a significantly higher success rate (85% vs 63%) in the standardized group. This suggests that standardizing imaging protocols for Pavlik harness treatment can lead to improved success rates.

OP-175

Utility of “Pavlik holiday” for infantile hip dysplasia following failure of Pavlik harness treatment

Maia Shoham, Hiba Naz, Nicole S Pham, Stephanie Pun, Kali Tileston, Meghan N Imrie

Stanford University, Stanford, CA, USA

LOE-Therapeutic-Level IV

Purpose: Pavlik harness is 90% successful in treating developmental dysplasia of the hip (DDH). We present a case series of infantile dysplastic hips that initially failed Pavlik treatment but went on to successful reduction with a second round of brace treatment after a harness-free interval—a “Pavlik holiday.”

Methods: We retrospectively identified patients with nonteratologic, dislocated hips that underwent a Pavlik holiday in a pediatric orthopedic tertiary care center. Hip dislocation was defined as a positive Ortolani sign and/or reduced femoral head coverage (FHC) (<30%) on ultrasound. Hips that did not reduce after 3–4 weeks of full-time Pavlik treatment were instructed to discontinue the Pavlik harness for a period, a “Pavlik holiday,” after which it was reinstituted full time. Hips were reassessed clinically and radiographically every 2–3 weeks during the second trial of bracing prior to considering reduction of the hip in the operating room. Success was defined as hips that reduced with a second round of Pavlik harness treatment and did not require closed or open reduction in the operating room. Mann–Whitney and Fisher’s exact tests compared age, clinical features, ultrasound measurements, and length of time in-harness or on Pavlik holiday between successful and unsuccessful patients.

Results: Twenty-one hips from 16 patients (13 female, 3 male) were given a Pavlik holiday after initial harness treatment failed to reduce the hip. Eleven (52%) hips successfully reduced during a second round of Pavlik treatment following the holiday. Median age at initial Pavlik application was 5.9 weeks (range 0.9–13.9). All hips were dislocated on initial ultrasound (median %FHC 15, alpha angle 49), and 13 were Ortolani-positive. The first round of Pavlik treatment lasted for a median of 22 days in the successful group and 27.5 days for the unsuccessful group (p = 0.096). Median holiday duration was 28 days (range 8–67). Median duration of the second Pavlik treatment was 65 days in the successful group with final %FHC of 60.

Conclusions: A “Pavlik holiday” rescued approximately half of dislocated hips that failed a first round of treatment. Future investigations will focus on risk factors for failing Pavlik treatment and predictive factors for success of the “Pavlik holiday.”

Significance: We have demonstrated a 50% success rate with a second Pavlik harness trial following initial unsuccessful reduction. This can be implemented while patients wait until they are large enough to undergo spica casting and therefore has the potential to avoid more invasive intervention without delaying care.

EPOS/POSNA Abstract Book (100)

OP-176

Predicting the resolution of residual acetabular dysplasia following successful brace treatment for developmental dysplasia of the hip in infants

Ayesha Saeed, Catharine Bradley, Yashvi Verma, Simon P Kelley

The Hospital for Sick Children (SickKids), Toronto, ON, Canada

LOE-Prognostic-Level II

Purpose: Successful bracing for developmental dysplasia of the hip (DDH) in infancy is characterized by normal clinical examination and hip ultrasound at the end of treatment. However, radiographic residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had DDH treated in infancy. It is important to predict those that will resolve and those that may need corrective surgery to optimize efficient follow-up protocols. We therefore aimed to identify the prevalence and predictors of RAD at 2 years and 5 years after bracing and identify factors that predicted spontaneous resolution.

Methods: This was a single-center, prospective longitudinal cohort study of infants with DDH managed using a published, standardized Pavlik harness protocol between 2012 and 2016. RAD was measured at a mean follow-up of 2 years using acetabular index-lateral edge (AI-L) and acetabular index-sourcil (AI-S). At 5 years, RAD was measured using AI-L, AI-S, center-edge angle (CEA), and acetabular depth ratio (ADR). At both timepoints, each hip was classified based on published normative values for normal, borderline (1–2 SD), or dysplastic (>2 SD) based on sex, age, and laterality.

Results: Of 202 infants that completed the protocol, 181 (90%) had 2- and 5-year follow-up radiographs. At 2 years, in 304 initially pathologic hips, based on AI-L and AI-S, the prevalence of RAD (dysplasia) was 10%, and RAD (borderline) was 30%. At 5 years, RAD (dysplasia) based on any measure decreased to 1%–3%, and RAD (borderline) decreased to <1%–2%. On logistic regression, no variables were predictive of RAD at 2 years. Only AI-L at 2 years was predictive of persistent RAD at 5 years (p < 0.001). Heat mapping of hips at 2 and 5 years showed that if both hips were normal at 2-year follow-up (n = 96), all remained normal at 5 years. In those with bilateral borderline hips at 2 years (n = 21), only two were borderline at 5 years, none were dysplastic. In those with either borderline-dysplastic or bilateral dysplasia at 2 years (n = 26), three (12%) had dysplasia at 5 years.

Conclusions: The vast majority of RAD at 2 years after brace treatment spontaneously resolved by 5-year follow-up without surgical intervention. Children with normal radiographs at 2 years after brace treatment can be discharged from care. Targeted follow-up for those with abnormal AI-L at 2 years will identify those few that may benefit from surgical correction at 5-year follow-up.

Significance: Our evidence-based pragmatic approach to DDH follow-up will inform efficient follow-up protocols and reduce unnecessary exposure to radiography.

OP-177

Residual acetabular dysplasia at walking age: a study of 470 hips treated with Pavlik harness

Luckshman Bavan, Thomas Lloyd, Lucy Llewellyn-Stanton, Max Mifsud, Alpesh Kothari

Oxford University Hospitals NHS Foundation Trust, Oxford, UK

LOE-Prognostic-Level III

Purpose: This study aims to report on the acetabular indices of walking age children following successful DDH treatment with Pavlik harness and investigate risk factors for residual acetabular dysplasia (RAD).

Methods: We retrospectively reviewed the data for children treated for DDH at a single center between 2015 and 2020. Acetabular indices (AI) measured on pelvic radiographs taken at 2- and 4-year follow-up visits were referenced against age- and sex-matched normal data. Values above the 90th percentile were considered to represent RAD.

Results: A total of 305 children (256:49 F:M) with 470 successfully treated hips were suitable for inclusion. Mean age at treatment initiation was 7.0 ± 4.5 weeks, and mean treatment duration was 15.9 ± 4.3 weeks. Of the 470, 27% and 19% of hips were found to have RAD at 2-year (n = 448, mean age 26 ± 3 months) and 4-year (n = 208, mean age 44 ± 6 months) follow-up, respectively. The chi-square test for independence demonstrated the relationship between age and incidence of RAD was significant (p = 0.032). Patients with RAD at 2 years were found to have been treated for longer (p = 0.028) and had lower alpha angles on final ultrasound assessment (p < 0.001). Patients with RAD at 4 years were older at initiation of treatment (p = 0.041), had lower alpha angles on final ultrasound assessment (p = 0.001), and were more likely to have had RAD at 2 years (p < 0.001). Multivariate analysis identified lower alpha angles on final ultrasound to be the only predictor for RAD at 2 years (odds ratio (OR) 1.08, 95% CI 1.02–1.14, p = 0.011), and presence of RAD at 2 years to be the only predictor for RAD at 4 years (OR 18.4, 95% CI 6.3–54.2, p < 0.001).

Conclusions: The risk of RAD beyond walking age in children successfully treated with Pavlik harness is not negligible. However, we observed that a significant proportion of children with RAD at 2-year follow-up had spontaneously improved without any intervention.

Significance: These data suggest that routine long-term radiological follow-up of children treated with Pavlik harness is necessary. Based on our findings, we would recommend delaying surgical intervention to address RAD until at least 4 years of age.

EPOS/POSNA Abstract Book (101)

OP-178

Salter innominate osteotomy for the treatment of developmental dysplasia of the hip in children: Results of 99 consecutive osteotomies after 13–34 years of follow-up

Renee Anne Van Stralen, Ena Colo, Allard Hosman, Wim Willem Schreurs

Radboud UMC, Nijmegen, The Netherlands

LOE-Therapeutic-Level IV

Purpose: Reorientation of the acetabulum might be indicated to achieve a concentric and stable hip in children with developmental hip dysplasia. This study describes the long-term results after Salter pelvic osteotomies at our institution.

Methods: Between 1981 and 2002, 99 Salter osteotomies have been performed at our institution in 76 patients without underlying neuromuscular pathology. Patients underwent a physical examination, clinical assessment was performed by Harris Hip Score (HHS), the Oxford score, and Visual Acuity Score (VAS), and patients had pelvic radiographs taken.

Results: Two patients (three hips) were excluded, and 15 patients (19 hips) were lost to follow-up. The median follow-up was 22 years (range 13–34 years). A total hip arthroplasty (THA) was performed in 6 out of 77 hips (8%). There was a significantly higher rate of AVN in the population of children undergoing a Salter with an open reduction (p < 0.001). There were statistically significant differences in the group with and without AVN regarding HHS (p = 0.006), Oxford hip score (p = 0.016), Modified Oxford hip score (p = 0.018), VAS score in activity (p = 0.046), and VAS score satisfaction (p = 0.005).

Conclusions: The rate of THA was 8% at follow-up. Secondary results suggest that AVN occurs more frequently when a Salter osteotomy is combined with an open reduction. When AVN occurs, clinical outcome scores and patient satisfaction are significantly lower and pain scores are significantly higher. If there is no AVN and a well-reduced hip can be achieved, good clinical results can be expected at a long-term follow-up.

Significance: This study further emphasizes the sustained effect of the Salter innominate osteotomy in children with developmental dysplasia of the hip. It can also help us counsel patients better about the long-term consequences of the condition and the surgery.

EPOS/POSNA Abstract Book (102)

OP-179

Outcomes following closed reduction for developmental dislocation of the hip

Michele Cerasani, Christina Herrero, Ronald McCartney, Aurelio Alberto Muzaurieta, Pablo Castañeda

NYU Langone Orthopedics, New York, NY, USA

LOE-Therapeutic-Level IV

Purpose: The goal in treating developmental dislocation of the hip is to establish a stable, congruent, and concentric motion between the growing components of the joint: while minimizing complications. While nonoperative treatments are preferred, there are instances where brace treatment is impractical due to age constraints or ineffectiveness. In such cases, closed reduction has classically been considered the next line of treatment. This is a retrospective analysis of a consecutive single-surgeon series, aimed to evaluate midterm outcomes for patients who underwent closed reduction for developmental hip dislocation.

Methods: This is a retrospective review of 103 hips that underwent closed reduction. The mean age at the time of reduction was 10.3 months, and the minimum follow-up was 6 years, with a mean of 7.4 years. To assess outcomes, we employed the Severin classification for radiographic results and determined the rates of proximal femoral growth disturbance and the necessity for secondary procedures.

Results: Of the 103 patients who underwent closed reduction, 44% (45 hips) achieved Severin types 1 or 2, while 49% (50 hips) ended as Severin types 3 or 4. We found a redislocation rate of 7% (7 hips). We identified proximal femoral growth disturbance in 19% (20 hips) of cases, and we found that 50% (52 hips) required a secondary intervention. Notably, for patients who transitioned to closed reduction following unsuccessful brace treatment, our findings were striking. In this cohort, comprising seven patients who failed with the Pavlik method and subsequently underwent closed reduction, five of the 7 exhibited proximal femoral growth disturbance, and six required further surgical intervention.

Conclusions: Our series found the likelihood of requiring a secondary procedure after a closed reduction in the treatment of developmental dislocation of the hip to be high and the risk of presenting PFGD to be significant. It also underscores that closed reduction after failed brace treatment carried a notably high risk of proximal femoral growth disturbance and the subsequent need for additional surgery.

Significance: While prioritizing nonsurgical options as a first-line treatment is a prudent approach, it is equally vital to provide parents with comprehensive information about potential treatment options and their associated outcomes.

OP-180

Closed reduction in developmental dysplasia of hip: predicting acetabular remodeling at skeletal maturity

Evelyn Kuong, Janus Wong, Wang Chow

Hong Kong Children’s Hospital, Hong Kong, Hong Kong

LOE-Prognostic-Level III

Purpose: Outcomes after early closed reduction of developmental dysplasia of hip (DDH) are occasionally unpredictable. Here, we develop a clinical model depicting age-specific risk profiles, to guide clinical decisions in optimizing long-term outcomes.

Methods: Children with DDH at two tertiary pediatric orthopedic centers over a 53-year-period with minimum follow-up until skeletal maturity were examined. Only hips that underwent closed reduction before 2 years of age were included. Those with open reduction, neuromuscular disorders, collagenopathies, chromosomal, or syndromic disorders were excluded. Radiographs since birth were retrieved with assessment of Tonnis grading, acetabular index (AI), lateral center edge angle, proximal femoral growth disturbance acetabular angle, and Severin grading. Primary outcomes involve development of a prognostication model to predict risk of good (Severin grades I or II) or poor (Severin grades III or above) hip outcomes. Secondary outcomes involved differences in hip outcomes with reference to age-specific acetabular indices, proximal femoral growth disturbance, initial Tonnis grading, gender, and age of reduction.

Results: A total of 2068 radiographs from 101 hips were analyzed. Mean follow-up was 19.2 years, with maximal follow-up at 46 years. The mean age at reduction was 9 ± 7 months. Femoral osteotomies were later performed in 14 hips, while pelvic osteotomies were performed in six hips (2 Salters, 1 Dega, 1 triple, and 2 shelf procedures). Hip arthroplasty was performed in one patient at follow-up of 46 years. Eight-two percent of hips experienced good Severin outcomes. Proximal femoral growth disturbance was present in 13%. Acetabular angle at latest follow-up (before triple, shelf, and arthroplasty) was 45 ± 4 degrees, with lateral center edge angle of 25 ± 8 degrees. Children with poor outcomes had higher AI across all ages (p < 0.01). Prereduction AI is a strong predictor of poor long-term outcome at skeletal maturity, with area under receiver operating characteristic (ROC) curve of 0.843 (95% CI 0.788–0.898, p < 0.01). Prereduction AI exceeding 33 degrees predicts poor outcome with 87% specificity and 62% sensitivity. Reduction after 3 months of age (p = 0.035) and growth disturbance (p < 0.01) were also predictive of poorer long-term outcomes. Earlier reduction before 6 months (6% vs 27%, p = 0.016) was associated with decreased risk of future surgery.

Conclusions: Closed reduction before 6 months of age is associated with decreased risk of future surgery. Prereduction AI of over 33 degrees at any age is associated with poor outcomes.

Significance: A personalized risk assessment chart visualizes our model developed from support vector machine algorithm, with age and AI as axis variables, attaining an accuracy of 84%.

EPOS/POSNA Abstract Book (103)

OP-181

Acetabular remodeling in developmental dysplasia of the hip: a tri-center analysis of open versus closed reduction in 459 hips

William Zachary Morris, Eduardo Novais, Patricia E Miller, Samantha L Ferraro, Laura M Mayfield, Wudbhav N Sankar

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level III

Purpose: This study aims to compare acetabular remodeling following closed and open reduction for developmental dysplasia of the hip (DDH).

Methods: This is a three-center, institutional review board (IRB)-approved study. We identified 538 hips from 459 patients aged 0–24 months who underwent an isolated closed or open reduction for DDH between 2000 and 2018. Serial radiographs were reviewed, and acetabular index (AI) measurements were assessed at follow-up visits. Only the initial hip treated per patient was analyzed. General additive modeling evaluated acetabular remodeling’s temporal shape and extent by treatment group and patient sex. AI measurements for males and females were compared to age-specific normative AI values throughout follow-up. Multivariable logistic regression identified factors associated with failure to remodel within normal limits by age 4.

Results: Thirty-six percent (166/459) underwent open reduction, while 64% (293/459) underwent closed reduction. Hips undergoing open reduction were slightly older (mean age 10.4 vs 8.9 months; p = 0.002), with a higher proportion of IHDI grade-4 (41% vs 15%; p < 0.001). Patients were followed up until they reached an endpoint (additional intervention or last radiographic follow-up) for a median of 5 years (IQR, 4.4–6.7 years). AI remodeling showed no significant difference over time across reduction groups (p = 0.90). However, IHDI grade-4 hips treated with closed reduction displayed poorer remodeling patterns than IHDI grade-4 hips undergoing open reduction (p < 0.001; Figure 1). By age 4, 66% (303/459) of the cohort achieved correction within 95% of the normal AI range. Multivariable analysis revealed that each additional year of age at reduction increased the odds of not remodeling within normal limits by 2.6 times (OR = 2.57; 95% CI, 1.35–4.87; p = 0.004). Patients with IHDI grade-4 (OR = 2.12; 95% CI, 1.21–3.69; p = 0.008) and males (OR = 2.12; 95% CI, 1.06–4.22; p = 0.03) were less likely to remodel to normal AI by age 4. In addition, each additional degree of prereduction AI increased the odds of not remodeling by 15% (OR = 1.15; 95% CI, 1.09–1.20; p < 0.001).

Conclusions: Overall, no significant difference in AI improvement rate was observed between hips undergoing closed or open reduction within the first 9 years postreduction. However, IHDI grade-4 hips treated with closed reduction exhibited less favorable remodeling patterns than those with open reduction. Furthermore, older age at reduction, IHDI grade-4, male sex, and more severe preoperative AI were independent factors associated with failure to remodel within normal limits by age 4.

Significance: This comprehensive analysis of 459 hips presents significant implications for clinical decision-making in DDH treatment, particularly for IHDI grade-4 hips. While both closed and open reduction have comparable remodeling for lower-grade cases, our results suggest considering open reduction for IHDI grade-4 hips to achieve superior acetabular remodeling.

EPOS/POSNA Abstract Book (104)

OP-182

Reevaluating the role of triradiate cartilage status in shaping curve progression among patients with juvenile idiopathic scoliosis

Hong Zhang, Chan-Hee Jo, Daniel J Sucato

Scottish Rite for Children, Dallas, TX, USA

LOE-Prognostic-Level III

Purpose: Triradiate cartilage (TRC) plays a pivotal role in assessing the maturation status of patients undergoing scoliosis treatment to determine risk for curve progression. Our hypothesis posits that the closure of the TRC marks the initial peak in curve progression among patients with juvenile idiopathic scoliosis (JIS). Our primary objective is to investigate whether the status of the TRC can function as an independent radiographic parameter, assessing its relationship with curve progression.

Methods: We conducted a longitudinal evaluation of 185 individuals diagnosed with JIS, comprising 126 girls and 59 boys, with an average age of 9.7 ± 1.5 years. These patients, all initially presenting with open-TRC, eventually underwent surgery during adolescence. Serial radiographs were utilized to monitor their progress, with an average follow-up period of 7.7 years. The TRC was categorized into three distinct statuses: (1) open-TRC: the TRC remained unfused. (2) Closing-TRC: a nonfused remnant was visualized. (3) Closed-TRC: the TRC was no longer visible, occurring prior to the initial appearance of the Risser sign. For each stage, we measured the main Cobb angles and calculated the curve progression rate per month. Subsequently, we correlated the TRC status with curve progression.

Results: The average duration for the closing-TRC was 1.1 ± 0.5 years, occurring between the ages of 11.2 ± 0.9 and 12.3 ± 1.1 years in girls. In contrast, boys experienced a longer period for the closing-TRC, spanning from the age of 13 ± 1.1 to 14.4 ± 1.1 years, which was 1.8 to 2.1 years later than girls. During the closing-TRC phase, curve progression exhibited distinct patterns. In girls, it averaged 1.4°± 1.0 per month, while in boys, it was slightly lower at 1.3°± 0.8 per month. These rates were significantly higher than those observed during the open-TRC phase (0.5°± 0.5 per month in girls and 0.3°± 0.7 per month in boys) (p < 0.0001). The duration of the closed-TRC phase until the appearance of the Risser sign was 9.2 ± 5.0 months in girls, while in boys, it was notably shorter, at 0.8 ± 4.6 months.

Conclusions: Our findings indicate that scoliotic curves in association with a closing-TRC exhibited significantly greater progression than those with an open TRC. The presence of a closing-TRC serves as a valuable indicator, signifying a critical period of scoliosis progression.

Significance: The closing-TRC may prove particularly valuable in guiding treatment decisions, especially in cases with borderline indications for the management of JIS.

OP-183

Increased thoracic sagittal spine length improves pulmonary function in early-onset scoliosis

Matt Holloway, Todd F Ritzman, Lorena Floccari, Richard Steiner, Jennifer Hurry, Amir Mishreky, Ron El-Hawary, Pediatric Spine Study Group

Akron Children’s Hospital, Akron, OH, USA

LOE-Prognostic-Level IV

Purpose: Early-onset scoliosis (EOS) can result in thoracic insufficiency syndrome (TIS), leading to significant morbidity or early mortality primarily attributable to restrictive lung disease. Growth-friendly EOS surgery can control curve progression and sustain growth until adequate thoracic height is achieved to avoid TIS. The traditional T1–T12 measurement of spine growth on coronal radiographs overlooks out-of-plane increases in spine length leading to an underestimation of the growth effects of surgical interventions. Sagittal spine length (SSL) measured from T1 L1 has been validated to reliably assess the length of the thoracic spine along the sagittal arc of curvature and account for this deficiency. Pulmonary function tests (PFTs), specifically forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and FEV1/FVC are recommended for EOS patients prior to and following surgical intervention, but it is unknown how these correlate to SSL.

Methods: This was a multicenter retrospective review of data collected prospectively. EOS patients with both postdefinitive fusion radiographs and PFT data available, excluding neuromuscular and syndromic etiologies, had SSL measured (n = 49). Pearson correlations between PFT data and SSL were analyzed.

Results: Actual FEV1 and actual FVC had statistically significant positive correlations with SSL (FEV1 r = 0.334, p = 0.007; FVC r = 0.331, p = 0.008). FEV1 predicted, FVC predicted, and FEV1/FVC ratio did not have a statistically significant correlation with SSL. Linear regression models were also built for pulmonary function variables with statistically significant correlations to further describe the relationships with SSL.

Conclusions: This study confirms the hypothesis that a positive correlation exists between SSL and postoperative FEV1a and FVC. Because of the statistically significant correlations between SSL and PFTs, SSL can be used as a predictive measure of pulmonary function following definitive fusion.

Significance: Further long-term PFT follow-up evaluation of a larger population of postdefinitive fusion EOS patients has potential to clarify a definitive ideal thoracic length as measured by SSL which is preventive of the disabling complication of TIS.

OP-184

Documenting the variation of proximal foundation constructs and their correlation with unplanned return to the operating room in children with magnetically controlled growing rods

Bahar Shahidi, Fernando Rios, Hazem Elsebaie, Bailee Monjazeb, William Kerr, Joshua Pahys, Steven Hwang, Amer F Samdani, Lindsay Andras, Matthew E Oetgen, Peter O Newton, Burt Yaszay, Peter F Sturm, Michael G Vitale, Paul D Sponseller, Gregory Mundis, Behrooz A Akbarnia, Pediatric Spine Study Group

Pediatric Spine Foundation, Valley Forge, PA, USA

LOE-Therapeutic-Level IV

Purpose: The evolution of magnetically controlled growing rod (MCGR) technique has led to modifications in the configuration of the proximal construct to decrease the incidence of implant-related complications (IRCs) and revision surgeries. However, there are no data characterizing the performance of the most used configurations reducing risk of complications.

Methods: A total of 487 patients were identified from an international multicenter EOS database. Inclusion criteria were EOS patients, primary dual MCGR, age ≤ 9 years, complete radiographs, and minimum of 2 years in follow-up. Seventy-six patients had incomplete x-rays, five had apical fusions, and 18 had inconclusive complications status leaving 388 patients for review. A digital spine template was created to document UIV; number of levels; number, type, and location of anchors; as well as implant configuration. We reviewed the first available postoperative and latest follow-up radiographs by a group of two senior surgeons and two spine fellows. Unplanned return to the operating room (UPROR) due to IRC was defined as any change in proximal anchors between the postoperative and final follow-up radiographs.

Results: The most common proximal construct configuration: UIV at T2 (50.0%) with 17.5% UPROR, followed by T3 (34.0%) with 12.1% UPROR; number of levels was 3 (57.1%) with 16.8% UPROR, and 2 (26.0%) with 17.0% UPROR; number of proximal anchors was 6 (49.9%) with 14.1% UPROR, and 4 (27.0%) with 18.3% UPROR. The most common types of anchors were all screws (42.0%) with 9.9% UPROR, and all hooks (26.4%) with 31.4% UPROR (p < 0.001). The most protective construct (nine cases) was UIV at T3 across three levels with six anchors, screws, and hooks (0% UPROR) followed by UIV at T3, across three levels (28 cases) with six anchors, hooks (7.1% UPROR). The most common construct (46 cases) was UIV at T3, with six anchors, screws (17.4% UPROR).

Conclusions: Proximal anchor configuration impacts the incidence of implant-related UPROR in MCGR. The most protective (T3 UIV, 3 levels, 6 anchors, screws, and hooks) was used in only 2.3% of cases.

Significance: Proximal construct configuration, including the upper instrumented vertebra (UIV), the number of foundational levels, and the number and type of anchors, is an important factor affecting the outcomes of MCGR. We found that the most utilized configurations are not the most protective against UPROR.

EPOS/POSNA Abstract Book (105)

OP-185

More screws, more OR time, same failure rates: enabling technology use in proximal fixation of growing spine constructs

Daniel Gabriel, Sydney Lee, Shanika De Silva, Daniel Hedequist, Craig Munro Birch, Brian D Snyder, Michael T Hresko, Grant Douglas Hogue

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level III

Purpose: Over the last decade, enabling technology has shown promise in enhancing construct placement accuracy and reducing complications in spine surgery. However, its role in growth-friendly spine surgery remains underexplored.

Methods: In this retrospective single-center cohort study, patients were included if they had a diagnosis of early-onset scoliosis (EOS) and underwent instrumented growth-friendly surgery with traditional growing rods (TGRs) or magnetically controlled growing rods (MCGRs) from 2013 to 2023. Those with a history of prior spine surgery were excluded. Key metrics including proximal anchor density (defined as the number of anchors per vertebral level), proximal fixation failure rates, operative time, and unplanned returns to the operating room were compared between ET patients and non-ET patients using t-tests, Wilcoxon rank sum tests, or Fisher’s exact tests.

Results: Of the 123 eligible patients (48% female), 34 received enabling technology assistance, primarily via CT-based O-arm guidance (one case utilized both O-arm and robotic guidance), while 89 underwent traditional fluoroscopic surgery. The mean age at the index surgery was 7.4 ± 2.8 years, average follow-up was 51 months, and average body mass index (BMI) was 16.4 ± 2.7. Preoperative Cobb angles averaged 77.4 ± 23.9 (major) and 43.2 ± 17.6 (minor). ET-assisted patients had a significantly higher screw-based proximal anchor density (1.3 vs 0.0, p < 0.001) but longer operative times (374 mins vs 272 mins, p < 0.001). There were no significant differences in proximal fixation failure rates (p = 0.5) or unplanned returns to the operating room (p = 0.6). ET use was found to be increasing over the past decade.

Conclusions: Enabling technology in growth-friendly pediatric spine deformity surgery increased screw-based anchor density and higher operative times but did not significantly alter proximal fixation failure rates or unplanned revisions in this cohort.

Significance: This study fills a critical knowledge gap in understanding the impact of enabling technology in growth-friendly spine surgery for pediatric spine deformities, offering insights into its potential benefits and areas for improvement.

EPOS/POSNA Abstract Book (106)

OP-186

The risks and benefits of definitive surgery in the graduation of i-EOS patients whose deformities were managed with GR: a comparison with matched AIS patients

Gokay Dursun, Rafik Ramazanov, Halil Gokhan Demirkiran, Mehmet Ayvaz, Muharrem Yazici

Hacettepe University, Ankara, Turkey

LOE-Therapeutic-Level II

Purpose: Early-onset scoliosis (EOS) is a progressive, life-threatening condition that needs to be treated carefully. Treatment with growing rods (GR) is the most frequently preferred method and is usually followed by posterior instrumentation and fusion (PIF), which is also called graduation. Graduation surgery is technically demanding and complicated, leading to a preference for avoiding definitive fusion when there’s adequate improvement in scoliosis angle, no implant failure, and no need to change instrumentation level. The aim of this study is to compare the risks and benefits of instrumented posterior fusion between patients with adolescent idiopathic scoliosis (AIS) treated with standard PIF and patients with idiopathic EOS treated with GR and graduated with PIF.

Methods: This is a retrospective study, included patients with idiopathic EOS who underwent dual-GR and definitive surgery, as well as those who underwent standard PIF with AIS during the study period. The AIS and the EOS groups were matched in terms of angle, T2–T12 kyphosis, L1 S1 lordosis, gender, and age variables by Propensity Score Matching analysis (Method nearest 1:3).

Results: One hundred seventy-six patients (24 EOS, 152 AIS) were included in the study. Seventy-two AIS patients were matched against 24 EOS patients. Statistically significant differences were found between the groups in terms of scoliosis correction percentage, surgery time, transfusion need, and number of instrumented segments. The percentage of T1–T12 increase, percentage of T1 S1 increase, instrumented spinal segment length increase, and the estimated blood loss (EBL) were similar (Table 1). Complications were seen in six patients in the EOS group. Intraoperative neuromonitoring alerts were seen in two patients, but both resolved with appropriate interventions. One superior mesenteric artery syndrome, two proximal anchor pull-outs, and one superficial infection were recorded. In the AIS group, three patients had complications (one trunk shift, one screw malpositioning, and one shoulder instability) and had to undergo revision surgery.

Conclusions: Although the EOS group had longer surgical time (53 minutes more), more bleeding (125 cc more), and less correction of the coronal deformity, trunk height gained by definitive surgery was the same as the AIS group. There is a difference in favor of AIS between the groups in terms of coronal deformity correction rates, but the final deformity size in EOS patients was clinically insignificant (20° (13–34)).

Significance: In conclusion, definitive fusion in EOS with idiopathic etiology does not carry an excessive risk for complications, and the gains obtained by the patients at the end of surgery are remarkable.

EPOS/POSNA Abstract Book (107)

OP-187

Lessons learned from 20 years of history using Vertical Expandable Prosthetic Titanium Rib (VEPTR) in early-onset scoliosis patients

Norman Ramirez-Lluch, Alexandra M Claudio-Marcano, John T Smith, John B Emans, Amer F Samdani, Mark A Erickson, John “Jack” M Flynn, Norberto J Torres-Lugo, Gerardo Olivella, Pediatric Spine Study Group

University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico

LOE-Not Applicable-Level III

Purpose: The use of Vertical Expandable Prosthetic Titanium Rib (VEPTR) for treating early-onset scoliosis (EOS) has markedly declined. At the verge of the VEPTR era, we assessed 20 years of this device’s outcomes, encompassing coronal correction, spine growth height, pulmonary function, complication rates, and the impact on health-related quality of life (HRQoL). We analyzed all EOS patients from the Pediatric Spine Study Group (PSSG) registry who were treated initially with VEPTR and followed up for at least 5 years.

Methods: We examined demographic and radiographic parameters, pulmonary function tests, 24-Item Early Onset Scoliosis Questionnaire (EOSQ-24) findings, and complications of all the patients from the PSSG database who underwent VEPTR instrumentation with a minimum of 5 years of follow-up.

Results: A total of 447 patients with a mean age of 4.24 + 2.62 years; 51.0% male were included. Fifty percent had congenital scoliosis, followed by neuromuscular (27.5%), syndromic (11.9%), and idiopathic etiologies (10.3%). Of these, 213 patients had at least one comorbidity. Thoracic insufficiency syndrome was the most common comorbidity. Five years after the initial surgery, 237 patients continued with VEPTR, 186 were fused, and 24 required hardware removal. Initial mean body mass index was 16.40 + 2.68 kg/m2; most recent was 17.42 + 4.08 kg/m2 (p < 0.001). Preoperative coronal Cobb angle was 66.94 + 23.59°; most recent was 56.71 + 18.85° (p < 0.001). Preoperative sagittal Cobb angle was 46.73 + 7.62°; most recent was 53.95 + 22.85° (p < 0.001). The T1 S1 spine height increased from 232.99 + 47.93 mm to 297.54 + 63.47 mm (p < 0.001), T1–T12 height changed from 141.63 + 33.87 mm to 188.33 + 43.35 mm (p < 0.001), and L1 S1 height went from 90.56 + 20.19 mm to 109.63 + 24.47 mm (p < 0.001). During the follow-up period, 82 patients underwent pulmonary function testing. Forced vital capacity (FVC) diminished from 61.92 + 31.58% to 46.84 + 20.18% (p < 0.001). Forced expiratory volume in one second (FEV1) decreased from 85.53 + 148.22 to 47.98 + 22.12 (p = 0.004). EOSQ-24 scores (N = 238) changed from 71.92 + 18.95 to 73.17 + 19.24 (p = 0.328). Seventy-two percent of patients had postoperative complications (336/447). Evaluation between all EOS categories showed better results in congenital scoliosis.

Conclusions: We present the most extensive sample of VEPTR utilization in the literature. The VEPTR’s objectives were to improve coronal deformity, stimulate spine growth, and hold respiratory function deterioration. Our results indicate that the first two objectives were achieved. However, the VEPTR technique could not prevent worsening of respiratory function. Similarly, no improvement in HRQoL was observed. Although we acknowledge the limitations of analyzing limited PFT/EOSQ data, it is important to highlight the trend observed in both parameters.

Significance: Due to high complication rates, we should continue to seek alternative treatments for EOS.

OP-188

Quality of life assessment in early-onset scoliosis: a comparison between the EOSQ-24 and EOSQ-SELF questionnaires on the same patients with two different respondents and time points

Barlas Goker, Gizem Kinikli, Yasemin Yavuz, Rafik Ramazanov, Ataberk Beydemir, Halil Gokhan Demirkiran, Muharrem Yazici

Hacettepe University, Ankara, Turkey

LOE-Not Applicable-Level III

Purpose: Twenty-four-Item Early Onset Scoliosis Questionnaire (EOSQ-24) is a parent proxy questionnaire designed to assess the health-related quality of life (HRQoL) of early-onset scoliosis (EOS) patients during their childhood years. EOSQ-SELF, a novel self-reported questionnaire, assesses HRQoL in older children (>8 years) and adolescents. So far, the same group of EOS patients has not been evaluated with both EOSQ-24 and EOSQ-SELF. The aim of this study was to evaluate how the same pathology was reflected in the parent and patient at different time points by comparing the answers to the common questions between EOSQ-24 and EOSQ-SELF.

Methods: A group of otherwise healthy idiopathic/idiopathic-like EOS patients whose parents filled out EOSQ-24 at the initiation of growth-friendly treatment was re-tested by the EOSQ-SELF questionnaire at the end of treatment. Both EOSQ-24 and EOSQ-SELF are validated in Turkish. Inclusion criteria were patients with EOS, independent ambulation, age over 8 years, literacy in Turkish, no apparent intellectual impairment, and minimum 24 months after graduation surgery. The common questions between the two surveys with nearly identical phrasings were extracted. Common items from the two tests were compared with a Wilcoxon signed rank test.

Results: Twenty-one patients (15 females, 6 males) who previously filled out EOSQ-24 met the inclusion criteria. The mean age of the group was 10.0 (5–16) years at EOSQ-24 participation and 18.0 (13–24) at the final analysis. There were nine congenital (40.9%), five juvenile idiopathic (22.7%), two low-tone neuromuscular scolioses (9.0%), two spina bifida (9.0%), one mucopolysaccharidosis (4.5%), one arthrogryposis (4.5%), and one secondary to a neuroblastoma resection (4.5%). Four patients had magnetically controlled (18.1%) and 17 had traditional growing rod instrumentation (77.2%). The mean number of surgeries was 10.2 (1–22). There were five cases of rod breakage (22.7%), two screw loosening (9.0%), two pullout (9.0%), and one infection (4.5%) that underwent revision. Ten patients graduated with definitive surgery (47.6%) and 11 graduated without (52.3%). Fourteen questions were found common in 10 domains (Table 1). The scores were significantly different in five questions of four domains. EOSQ-SELF had significantly less favorable scores in the pain/discomfort, pulmonary function, and fatigue/energy level domains, and scores in the parental burden/relationships domain were significantly higher (p < 0.05).

Conclusions: There was a general trend of worse results in the self-reported group. These findings suggest either parents or caregivers may not accurately perceive the problems of EOS patients, or EOSQ-24 may fail to demonstrate some challenges faced by patients over the treatment process.

Significance: First study to compare answers to similar questionnaires between the patients and proxies.

EPOS/POSNA Abstract Book (108)

OP-189

Utility of preoperative echocardiogram for large curve scoliosis patients

Chidebelum Nnake, Matan Malka, Alondra Concepción-González, Emma Berube, Nicole Bainton, Michael G Vitale, Benjamin D Roye, Joshua E Hyman

Morgan Stanley Children’s Hospital at New York Presbyterian, New York, NY, USA

LOE-Diagnostic-Level III

Purpose: Previous literature has demonstrated the need for adequate preoperative screening, including echocardiograms, to assess intraoperative risks in cases of severe scoliosis. However, in a relatively healthy population of patients with no prior cardiac history, the benefit of a screening echocardiogram is unclear. The purpose of this study is to quantify the incidence of cardiac findings in patients undergoing screening echocardiography based solely on curve magnitude, specifically those patients with curves ≥90°.

Methods: A single-institution retrospective chart review was performed ranging from 2018 to 2023. Inclusion criteria were patients with scoliosis curves ≥90° undergoing screening echocardiogram within 6 months of a surgical spine procedure. Exclusion criteria were patients with diagnoses associated with cardiac anomalies or dysfunction, previous cardiac history, or any patients with a primary sagittal plane deformity.

Results: Fifty patients met the inclusion criteria and were included in the study. The mean age at surgery was 14.0 ± 4.9 years. The mean magnitude of the major curve was 108 ± 18.7. Seventy-six percent of the patients had a normal echocardiogram, of which 33% were technically challenging to obtain. Abnormal findings were seen in 24% (Table 1) and included mild valvular regurgitation and dilation. No patient had their anesthetic plan modified. Only one patient was recommended to follow up with cardiology postoperatively, and their surgery went without complication. In terms of postoperative cardiac events, 42 (84.0%) of the patients had none. Eight patients (14.0%) were given vasopressors to increase mean arterial pressure to protect spinal cord function after significant intraoperative blood loss and/or changes in spinal cord monitoring. Cardiac dysfunction was not felt to be a contributing factor in any of these cases, and only one of these eight patients had positive findings on echocardiogram.

Conclusions: Echocardiograms were performed on patients with severe scoliosis, but no underlying cardiac history, cardiac symptoms, or diagnosis associated with cardiac comorbidities did not help in quantifying perioperative risk. Results were hard to interpret in one-fourth of the studies and did not produce actionable findings or contribute to anesthetic management.

Significance: Our study suggests screening echocardiograms in patients without any cardiac history, symptoms, or a diagnosis with a known association with cardiac comorbidities has low utility in this patient population. Creating clear, evidenced-based indications for screening exams, like echocardiograms, is important to assess preoperative risk responsibly and help minimize the scheduling, psycho-social, and financial burdens endured by families in this population.

OP-190

Intraoperative CT-based technology significantly increases radiation exposure in the pediatric population

Vishal Sarwahi, Sayyida Hasan, Keshin Visahan, Aravind Patil, Katherine Eigo, Sarah M Trent, Alex Kwong Juen Ngan, Yungtai Lo, Terry D Amaral

Northwell Health, New Hyde Park, NY, USA

LOE-Not Applicable-Level III

Purpose: In the past, pedicle screw insertion had been done using free-hand technique or fluoroscopy guidance. Recently, intraoperative CT-based navigation has been adopted to aid in visualization of pedicle screw insertion to allow for screw accuracy and safety in spine surgery. Albeit the safety benefits of this new technology, it runs the risk of increasing radiation exposure in this vulnerable population.

Methods: A retrospective chart review of 596 AIS patients between 2015 and 2023 from a single institution was done. One hundred ten patients were operated on with just CT-based technology (CT-nav group), 268 patients were operated on using fluoroscopy guidance, and 218 patients were operated on utilizing a hybrid, TNT (technique n’ technology), approach. Surgical and clinical outcomes were compared. Kruskal–Wallis test was done for continuous variables, and chi-square test was done for categorical variables.

Results: There were no significant differences in demographic or radiographic variables. CT-nav and TNT had a significantly higher radiation dose than fluoroscopy (p < 0.001), Ct-nav has the highest radiation dose at 21.2 mGy. CT-nav also had the highest time under radiation at 21.6 seconds (p < 0.001). Operative time in this group was significantly higher than that in the other two groups, taking 278.5 minutes to complete surgery (p < 0.001).

Conclusions: New technology in the medical field comes with advantages as well as disadvantages. In this case, CT-based technology can give surgeons confidence in their screw placement, creating a safer and more accurate procedure; however, the added radiation and operative time is harmful for adolescents.

Significance: Intraoperative CT-based technology leads to an increase in harmful radiation exposure in adolescents during spine surgery. This technology should be further explored.

OP-191

In the era of liposomal bupivacaine: is patient-controlled analgesia even needed?

Ernest Y Young, Ernest Dankwah, Ryan C Goodwin, David P Gurd, Thomas E Kuivila

Cleveland Clinic, Cleveland, OH, USA

LOE-Therapeutic-Level III

Purpose: In the face of the opiate epidemic, there is a directive to decrease opiate consumption in pediatric patients after surgery. At our institution, liposomal bupivacaine, delivered via erector spinae plane block (ESPB) prior to surgery, has been found to be an effective pain-controlling adjunct. Due to improved pain control with ESPB, our institution replaced patient-controlled analgesia (PCA) with as-needed intravenous and oral analgesia. This study was performed to compare opiate consumption, postoperative pain scores, length of stay (LOS), and mobility in patients treated with a PCA to those without PCA.

Methods: Retrospective chart review of consecutive patients undergoing posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) was performed. Pain control in both cohorts involved an ESPB with liposomal bupivacaine prior to incision and postoperative oral oxycodone, ketorolac, and gabapentin. The PCA group received 2 days of IV hydromorphone via the PCA. The non-PCA group instead received as-needed IV hydromorphone. Opioid consumption was measured via morphine milligram equivalents (MME). Pain scores were measured via the Visual Acuity Score (VAS). Patient mobility was measured by steps taken. These were measured by function of postoperative day from surgery (POD). Statistical analysis was performed using one-way analysis of variance and chi-square tests.

Results: Seventy-two consecutive patients undergoing PSF were reviewed. There were 36 patients in the PCA cohort and 36 in the non-PCA cohort. Patients were comparable in baseline characteristics in terms of age, gender, weight, blood loss, and number of levels fused (p > 0.05). The non-PCA group had significant lower MME at each point after surgery, most notably at POD-0 (18.4 vs 54.9, p < 0.01), POD-1 (28.8 vs 64.6, p < 0.01), and POD-2 (30.4 vs 47.2, p < 0.01) and throughout the entire hospital stay (99.8 vs 200.7, p < 0.05). Postoperative pain scores were no different at POD-0 (4.9 vs 4.8, p = 0.9), POD-1 (5.1 vs 5.2, p = 0.7), and POD 3 (4.3 vs 5.1, p = 0.4). There was a significant difference at POD-2, with the PCA cohort having more pain (6.0 vs 4.6, p = 0.02). There was no difference in mobility between the cohorts (p > 0.05). The non-PCA patients had a lower LOS (3.7 vs 4.1, p = 0.02).

Conclusions: In patients undergoing scoliosis surgery with ESPB, removal of the PCA reduced opiate consumption by half and lowered length of stay without any change in postoperative pain scores or mobility.

Significance: A PCA is not needed after scoliosis surgery with liposomal bupivacaine.

OP-192

Safety data for robotics coupled with navigation for pediatric spine surgery: initial intraoperative results of a prospective multicenter POSNA-funded registry

Nicole Welch, Alexa Bosco, Jeffrey Michael Henstenburg, Craig Munro Birch, Grant Douglas Hogue, Michael T Hresko, Mark A Erickson, Roger F Widmann, Jessica H Heyer, Kirsten Ross, Robert Francis Murphy, Dennis P Devito, Daniel Hedequist, SPARTAN

Boston Children’s Hospital, Boston, MA, USA

LOE-Therapeutic-Level I

Purpose: The utilization of robotics coupled with navigation (RCN) in pediatric spine surgery remains a relatively novel approach. This prospective multicenter registry seeks to evaluate the intraoperative efficacy, potential challenges, and complications associated with RCN. It was hypothesized that RCN for pedicle screw placement in pediatric spine surgery has a short-term complication profile equivalent to freehand screw placement.

Methods: A comprehensive review of prospectively consented patients, with multiple underlying diagnoses, who underwent posterior spinal fusion surgery using RCN at six pediatric institutions from 2021 to 2023 was conducted. Patient demographics, surgical data, RCN data, technical difficulties, intraoperative, and immediate postoperative complications were summarized.

Results: The registry consists of 186 patients averaging 15.1 years of age. Majority of patients are female (68%) with idiopathic scoliosis (60%). The mean preoperative major curve was 63°, and total number of levels instrumented averaged 10.2. RCN levels averaged 6.4 (62%). The robotic platform was mounted via spinous process clamp (80%) and posterior superior iliac spine pin (20%). RCN registration occurred an average of 1.2 times per patient. Thirty-eight patients had registration with preoperative CT (20%), and 146 had O-arm registration (79%). RCN was aborted due to failed registration in two cases (1%). Loss of registration was noted by safety check prior to drilling in 15 cases (8%). Technical difficulties with navigation occurred in 20 cases (11%) requiring recalibration. Inability to perform screw trajectories with RCN due to soft-tissue pressure on the robotic arm occurred in 26 patients (14%). A total of 3272 pedicle screws were placed. Of the 1369 freehand screws, 31 were mispositioned (2.26%), with four medial breaches (0.29%). A total of 1903 screws were executed with RCN (58%). Sixteen RCN screws were mispositioned (0.84%), with three medial breaches (0.16%). Based on granular screw data available for 124 patients, 297 in-out-in screw trajectories were attempted with RCN, of which 291 were executed successfully (98%). All mispositioned screws were redirected intraoperatively; thus, no returns to the operating room for screw malposition were observed. There were no dural tears or neurologic deficits related to screw placement (Table 1).

Conclusions: Prospective multicenter data confirm earlier retrospective studies outlining the safety and efficacy of RCN-assisted pediatric spine surgery.

Significance: This is the first prospective multicenter surgical outcomes registry evaluating the use of RCN in pediatric spine surgery. These initial intraoperative results show RCN is a promising technology in the pediatric spine space and warrants further study.

EPOS/POSNA Abstract Book (109)

OP-193

The impact of lumbar microdiscectomy in adolescents on PROMIS pain, physical function, and mental health domains

Scott J Luhmann, Read Abraham Streller

Washington University School of Medicine, St. Louis, MO, USA

LOE-Therapeutic-Level IV

Purpose: Lumbar microdiscectomy in adolescents is an infrequently performed procedure, reserved for pain and neurologic symptoms unresponsive to nonsurgical management. Most published studies have focused on the interventional impact on pain outcomes creating a paucity of data on physical function and mental health outcomes. The study hypothesis is PROMIS can detect changes in pain, physical function, and mental health in adolescents undergoing lumbar microdiscectomy.

Methods: This is a retrospective analysis including all patients (n = 36) who underwent a lumbar microdiscectomy surgery (34 single level, 2 multi-level) from a single surgeon at a tertiary-care pediatric hospital, identified from a surgical database. PROMIS scores (Mobility (MOB), Pain Interference (PI), Upper Extremity (UE), Physical Functioning (PF), Peer Relationships (PR), Anxiety, and Depression) were obtained preoperatively and at 6 weeks, 3 months, 6 months, 1 year, and 2+ years postoperatively.

Results: A total of 36 patients (24 female), whose mean age was 16.6 years at surgery (range, 13–20 years) were included in the analysis. Preoperatively, 3 patients had motor weakness, 11 lower-extremity numbness, and 35 radicular symptoms. Microdiscectomy levels were L4 L5 (n = 16), L5 S1 (n = 18), L4 S1 (n = 1), and L3 L5 (n = 1). Mean preoperative PROMIS scores: Mob 32.2 (range, 22.7–46.0), PI 62.5 (range, 47.0–77.8), UE 44.9 (range, 25.4–57.3), PF 37.2 (range, 33.6–41.5), PR 55.6 (range, 40.3–66.0), anxiety 56.2 (range, 50.6–67.1), and depression 48.5 (range, 31.9–61.6). Postoperatively, there were improvements in MOB (p = 0.05) at each time point, with a +11.3 improvement at 2 years (p = 0.0027). In PI, there was a significant decrease (p = 0.0001) immediately after surgery with sustained improvement (−8.6) at 2 years (p = 0.0009). For UE and PR, there was a statistically significant improvement from the preoperative baseline scores to the 1-year postoperative visit for UE (+10.6; p = 0.008) and PR (+8.0; p = 0.01), but no difference at 2 years. PF, anxiety, and depression domains did not demonstrate any statistically significant changes across any time intervals.

Conclusions: Using the PROMIS instrument, there were significant improvements postoperatively after lumbar microdiscectomy in adolescents in MOB, PI, UE, and PR up to 1 year postoperatively and continued improvement in MOB and PI. These data demonstrate PROMIS is a sensitive instrument detecting changes in these four commonly obtained domains over 2-year follow-up after surgery.

Significance: Using PROMIS, lumbar microdiscectomies in adolescents, who failed nonsurgical management, demonstrated improvements in pain, upper- and lower-extremity function, and peer relationships postoperatively.

EPOS/POSNA Abstract Book (110)

OP-194

What are the morphological risk factors for pediatric anterior cruciate ligament tears and tibial spine fractures?

Chang-Ho Shin, Akbar Nawaz Syed, Morgan Swanson, Theodore J Ganley, Tibial Spine Research Interest Group

Children’s Hospital of Philadelphia, Philadelphia, PA, USA

LOE-Not Applicable-Level III

Purpose: Tibial spine fractures (TSFs) are considered equivalent to midsubstance ruptures of the anterior cruciate ligament (ACL) in terms of injury mechanism. However, why some patients sustain ACL tears and others have TSF has yet to be fully revealed, with only two studies comparing the radiographic knee morphology between patients with ACL tears and TSF. We aimed to identify common morphological risk factors for ACL tears and TSF and determine the morphological difference between ACL tears and TSF.

Methods: One hundred fifty-nine age- and sex-matched patients under 18 years of age (53 ACL tears, 53 TSF, and 53 controls with anterior knee pain) who visited a single large pediatric hospital institution between March 2009 and April 2023 were study subjects. Forty-one patients were male, and 12 patients were female in each group. We retrospectively collected demographics and measured various parameters on multiplanar reconstruction MRI, including bone age, articular medial tibial slope (MTS) and lateral tibial slope (LTS), bony MTS and LTS, medial tibial depth (MTD), lateral compartment middle articular cartilage slope (LMCS), lateral compartment meniscus-bone angle (LMBA), lateral compartment meniscus-cartilage height (LMCH), lateral femoral condyle ratio (LFCR), alpha angle, intercondylar notch width index (NWI), and notch angle. The shape of the intercondylar notch was classified into U- or A-shapes. Parameters showing a significant difference among the groups in one-way ANOVA, Kruskal–Wallis test, chi-square test, or univariate multinomial logistic regression analysis were selected as independent variables for multivariate analysis.

Results: The mean age at MRI was 13.5 ± 2.2 years for males and 12.2 ± 2.5 years for females. Height, weight, BMI, bone age, articular MTS, bony MTS, MTD, and LMCH were not significantly different among the three groups (Table 1). In the multivariate multinomial logistic regression analysis, articular LTS was associated with the occurrence of ACL tears (relative risk ratio (RRR), 1.27 (95% CI, 1.12–1.43)) or TSF (RRR, 1.17 (95% CI, 1.04–1.32). The NWI was associated with ACL tears (RRR, 0.86; 95% CI, 0.77–0.95) but not with TSF (RRR, 1.01; 95% CI, 0.91–1.11).

Conclusions: High articular LTS is the common risk factor for both ACL tears and TSF. Patients with ACL tears have a narrow intercondylar notch compared to patients with TSF or controls.

Significance: This is the first study that compared knee morphology on MRI among ACL tears, TSF, and controls. The results of this study help bring light to a predisposition toward ACL tears over TSF under a similar injury mechanism in pediatric patients.

EPOS/POSNA Abstract Book (111)

OP-195

Dynamic point-of-care ultrasound is effective in the early diagnosis of anterior cruciate ligament injuries in children and adolescents

Marcell Benjamin Varga

Manninger Jenő Baleseti Központ, Budapest, Hungary

LOE-Diagnostic-Level III

Purpose: Several studies have proven that ultrasound (US) can improve the efficiency of early diagnostics of anterior cruciate ligament (ACL) injuries. ACL US is mainly performed by sonologists or radiologists. We have very little data on how effective these tests are if they are performed by an orthopedic surgeon. We also have no information on the applicability of ACL US in children and adolescents. In this retrospective study, we analyzed the results of point-of-care ultrasound (POCUS), which were performed by orthopedic surgeons on children with suspected ACL injury.

Methods: We reviewed the data of children and adolescents who were examined with ultrasound between 2018 and 2021 for suspected ACL injury. ACL POCUS was done immediately after the physical examination, according to a standard technique. The tests were performed by an orthopedic resident and young and a senior orthopedic surgeon. The inclusion criteria were as follows: The child’s age is between 0 and 15 years, the growth zones are open, the child later underwent MRI and/or arthroscopy, which confirmed or excluded the fact of an ACL injury. We excluded patients with incomplete recordings and documentation.

Results: One hundred nineteen children met the aforementioned criteria. The children were between 8 and 15 years of age (mean = 13.29). Positive findings were found in 47 and negative findings in 72 children with ACL POCUS. During the subsequent treatment, 57 children underwent only MRI examination, 11 children underwent only arthroscopy, and 51 children underwent both MRI and arthroscopy. The specificity of the test was measured as 0.958 and the sensitivity as 0.917 for complete ACL rupture. Regarding all ACL injuries (complete + partial), we found the sensitivity to be 83.019, and the specificity to be 95.45. The interrater agreement between radiologist and clinicians was 94.957% (Cohen’s k: 0.8945).

Conclusions: POCUS can indicate functional insufficiency caused by ACL injury in children and adolescents. The biggest advantage of the test is that it is quick and simple, as well as noninvasive. Further prospective diagnostic tests and standardized examination protocols can confirm our favorable experiences.

Significance: Cheap and simple method for the diagnosis of pediatric anterior cruciate ligament injuries.

OP-196

Low rates of complications following quadriceps tendon autograft ACL reconstruction in adolescents: strategies for success in the first 12 months

Crystal Perkins, Michael T Busch, Anthony Egger, Jason Kim, Erin Yuder, Shivangi Choudhary, Cliff Clifton Willimon

Children’s Healthcare of Atlanta, Atlanta, GA, USA

LOE-Therapeutic-Level II

Purpose: The use of quadriceps tendon autograft for ACL reconstruction has been associated with higher rates of complications, including arthrofibrosis, as compared to hamstring and patellar tendon autograft reconstructions. The purpose of this study was to describe complications in adolescent patients requiring reoperation within the first 12 months following ACL reconstruction with soft-tissue quadriceps tendon autograft (ACLR-Q).

Methods: A prospective single-center study was performed of all patients younger than 20 years who underwent ACL reconstruction with a soft-tissue quadriceps tendon autograft from 26 May 2020 to 28 February 2022. Patients were treated with postoperative bracing in extension until sufficient quadriceps control was obtained. A standard physical therapy protocol was utilized, emphasizing early terminal knee extension and return to sports no sooner than 9 months postoperatively pending appropriate strength and mechanics at 6-month functional testing. Postoperative outcomes were collected, including complications requiring reoperation, patient-reported outcome scores, and contralateral ACL injury.

Results: Three-hundred seventy patients, mean age 16 years (range 11–20 years), underwent ACLR-Q during the study window. Three-hundred nine patients (84%) had minimum 1-year follow-up and were included in this st