Acute Compartment Syndrome in Pediatric Patients on Extracorporeal Membrane Oxygenation Support.

BACKGROUND: When acute compartment syndrome (ACS) occurs in pediatric patients requiring venoarterial extracorporeal membrane oxygen (VA ECMO) support, there is little data to guide surgeons on appropriate management. The purpose of this study is to characterize the presentation, diagnosis, timeline, and outcomes of patients who developed this complication. METHODS: This is a single-center retrospective case series of children below 19 years old on VA ECMO support who subsequently developed extremity ACS between January 2016 and December 2022. Outcomes included fasciotomy findings, amputation, mortality, and documented function at the last follow-up. RESULTS: Of 343 patients on VA ECMO support, 18 (5.2%) were diagnosed with ACS a median 29 hours after starting ECMO. Initial cannulation sites included 8 femoral, 6 neck, and 4 central. Femoral artery cannulation was associated with an increased risk of ACS [odds ratio=6.0 (CI: 2.2 to 15), P <0.0001]. In the hospital, the mortality rate was 56% (10/18). Fourteen (78%) patients received fasciotomies a median of 1.2 hours after ACS diagnosis. Only 4 (29%) patients had all healthy muscles at initial fasciotomy, while 9 (64%) had poor muscular findings in at least 1 compartment. Patients with worse findings at fasciotomy had a significantly longer duration between ischemia onset and ACS diagnosis. Patients required a median of 1.5 additional procedures after fasciotomy, and only 1 (7%) developed a surgical site infection. Of the 7 surviving fasciotomy patients, 2 required amputations, 3 developed an equinus contracture, 1 developed foot drop, and 3 had no ACS-related deficits. Four patients did not receive fasciotomies: 3 were deemed too ill and later died, and 1 was diagnosed too late to benefit. The only surviving nonfasciotomy patient required bilateral amputations. CONCLUSIONS: Pediatric ECMO-associated ACS is not exclusive to patients with femoral artery cannulation. The majority of fasciotomy patients were diagnosed with ACS after muscle necrosis had already started. We were unable to definitively conclude whether fasciotomies provide better outcomes. There is a need for increased awareness and earlier recognition of this rare yet potentially devastating complication. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Half-pin Breakage in Multiplanar External Fixators Used for Pediatric Deformity Correction.

BACKGROUND: Pediatric patients with leg length discrepancies and complex deformities may require multiplanar external fixators for correction. We have encountered 4 cases of half-pin breakage with the Orthex hexapod frame. The purpose of this study is to report factors associated with half-pin breakage and compare various deformity correction characteristics between 2 hexapod frames - Taylor Spatial Frame (TSF) and Orthex. METHODS: Pediatric patients with lower extremity deformities treated with an Orthex or TSF at a single tertiary children's hospital between 2012 and 2022 were included for retrospective review. Variables compared between frame groups include frame configuration, half-pin/wire fixation, length achieved, angular correction, and frame time. RESULTS: There were 23 Orthex frames (23 patients) and 36 TSF (33 patients) included. Four Orthex and zero TSF had proximal half-pin breakage. The Orthex group was younger on average (10 vs. 12 y, P =.04*) at the time of frame placement. The majority (52%) of Orthex frames were used for simultaneous lengthening and angular correction, while the majority (61%) of TSF was used for only angular correction. Orthex had more half-pins used for proximal fixation (median 3 vs. 2, P <0.0001*) and more frames with nonstandard configuration (7 (30%) vs. 1 (3%), P =0.004*). Orthex group had a longer total frame time (median 189 vs. 146 days, P =0.012*) and longer time required for regenerate healing (117 vs. 89 d, P =0.02*). There were no significant differences in length gained, angular correction, or healing index between Orthex and TSF. Nonstandard configuration, increased number of proximal half-pins, younger age at index surgery, and increased lengthening were associated with pin breakage. CONCLUSIONS: This is the first study to report half-pin breakage while using multiplanar frames in pediatric lower extremity deformity correction. The Orthex and TSF groups consisted of significantly different patients and frame configurations, making it difficult to identify any specific cause for pin breakage. This study shows that pin breakage is likely caused by multiple factors and is associated with the increased complexity of deformity correction. LEVEL OF EVIDENCE: Level III-Retrospective Comparison Study.

Does the stabilization of the calcaneocuboid joint with Steinmann pin in Evans osteotomy affect its incidence of arthritis?

PURPOSE: This study aims to determine the effect of retaining a Steinmann pin in the calcaneocuboid joint on its rates of arthritis following Evans calcaneal osteotomy lengthening procedure. The study hypothesized that leaving the pin across the calcaneocuboid joint post-operatively would lead to higher rates of arthritis. METHODS: This is a retrospective review of patients under 18 years of age who underwent Evans osteotomy at our hospital from January 2015 to May 2020. The Patients were stratified into 2 groups: Group 1 (pin was left post-operatively across the joint and removed on follow-up) and Group 2 (pin was removed during surgery). Demographic data were recorded, including age, sex, and body mass index. Calcaneocuboid arthritis was determined by radiographic imaging at least one-year follow-up. Time to pin removal, size of the pin and graft, and subluxation were analyzed as possible risk factors for arthritis. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated. RESULTS: 39 patients were included in the study: 24 patients had the pin removed post-operatively, and 15 had the pin removed intra-operatively. There were no significant differences between the 2 groups regarding body mass index, age, sex, or laterality. Calcaneocuboid arthritis rates were significantly higher in the Group 1 than Group 2 (12(50%) vs. 2(13.3%), respectively; p = 0.02). On multivariate regression, both age (OR, 1.305 [95%CI: 1.009-1.696]; p = 0.044) and leaving the pin in the joint postoperatively (OR, 7.661 [95%CI: 1.208-48.570]; p = 0.031) were found as risk factors for arthritis at follow-up. The mean time to pin removal, the size of the pin, and the size of the graft were not found to be significant predictors of arthritis (p > 0.05). CONCLUSIONS: This study shows that leaving the Steinmann pin in the calcaneocuboid joint in children post-operatively is associated with an increased risk of developing early radiographic signs of calcaneocuboid joint arthritis.

Spica MRI predictors for epiphyseal osteonecrosis after closed reduction treatment of dysplasia of the hip.

Spica MRI with intravenous gadolinium contrast after closed reduction for developmental dysplasia of the hip (DDH) helps to determine successful reduction and attempts to identify patients at risk for epiphyseal osteonecrosis. The objective of our study was to evaluate spica MRI predictors for epiphyseal osteonecrosis after closed reduction. This was a retrospective study of all patients undergoing closed reduction for DDH followed by gadolinium-enhanced spica MRI between July 2011 and November 2014. Patient demographics and clinical follow-up through 2017, including the development of epiphyseal osteonecrosis and need for reintervention after the initial reduction, were recorded. MRI data included hip abduction angles and quantifying the percentage of femoral head enhancement. Twenty-five hips in 21 patients (16 girls, five boys, mean age: 0.99 years, range: 0.4-3.1 years) were included in our study. The mean follow-up period was 3 ± 1.5 years (range: 0.65-6.1 years). Eight (32%) of 25 hips went on to develop osteonecrosis. Epiphyseal osteonecrosis was more likely with less than 80% enhancement (sensitivity 87.5%, specificity 88.25%, positive predictive value 78%, negative predictive value 94%). The mean contrast enhancement for patients developing osteonecrosis compared with those who did not was 37.5 and 86.5%, respectively; P = 0.001. Immediate postspica MRI with gadolinium is a useful prognostic tool for determining future risk for epiphyseal osteonecrosis in children treated for DDH. Our data complement existing literature and suggest that even in cases with partial epiphyseal enhancement, osteonecrosis may still develop. When the epiphyseal enhancement is less than 80%, it is recommended that spica cast revision is considered.

Chronic Osteomyelitis Caused by Haemophilus parainfluenzae: A Case Report.

CASE: A 14-year-old boy presented with a pathologic fracture of the distal aspect of the tibia and a remote history of a dog bite near the injury site. Imaging studies, biopsy, and presentation corroborated the diagnosis of chronic osteomyelitis. Multiple diagnostic methods were negative until an open biopsy identified Haemophilus parainfluenzae, a fastidious oropharyngeal bacterium, with polymerase chain reaction analysis. The patient underwent extensive debridement, placement of external fixation, and a year-long antibiotic therapy regimen. He subsequently required a tibial-fibular osteotomy at a second site with placement of an intramedullary nail for correction of a leg-length discrepancy. CONCLUSION: This case report illustrates the complex management of chronic osteomyelitis in pediatric patients, its sequelae, and the importance of considering treatment of atypical pathogens.