Pelvic fixation in pediatric spinal fusion for neuromuscular scoliosis is associated with increased short-term complications but comparable long-term outcomes

Pelvic fixation is frequently used in posterior spinal fusion for neuromuscular scoliosis (NMS) to improve alignment and construct stability, particularly with significant pelvic obliquity. However, concerns remain regarding its association with increased surgical complexity and postoperative morbidity. This study compared short- and long-term postoperative outcomes between pediatric NMS patients who underwent posterior spinal fusion with and without pelvic fixation. A retrospective cohort study was conducted using the TriNetX Research Network, a federated database aggregating deidentified electronic health records from 106 healthcare organizations. Pediatric patients (≤21 years) with NMS who underwent posterior spinal fusion with or without pelvic fixation were identified. Before matching, 985 patients had undergone pelvic fixation, and 1492 had not. Following 1 : 1 propensity score matching, 592 matched pairs were retained for analysis. Matching controlled for differences in demographics, comorbidities, number of vertebral levels fused, and neuromuscular diagnosis. Postoperative complications were assessed at two time windows: short-term (1-365 days) and long-term (≥365 days). Pelvic fixation was associated with significantly higher short-term complication rates, including postoperative infections and wound breakdown. Mortality did not differ significantly between groups in either follow-up period. No statistically significant differences were observed in long-term complication rates, including pseudoarthrosis, revision surgery, and additional instrumentation. Pelvic fixation in pediatric posterior spinal fusion for NMS is associated with increased short-term morbidity, particularly wound complications and infections, which can affect recovery. Long-term outcomes, including hardware failure, pseudarthrosis, and revision, were comparable between groups. Careful perioperative management and counseling are essential when pelvic fixation is planned.