Pelvic Fixation for Non-Ambulatory Patients with Neuromuscular Scoliosis Treated with Magnetically Controlled Growing Rods-A 4-Year Comparison of Two Different Fixation Methods.

Background/Objectives : This study aims to analyze the efficacy and safety of the two pelvic fixation systems, S-hooks (SH) and lumbar-sacral-alar-iliac (SAI) screws, when used in association with magnetically controlled growing rods (MCGRs) in non-ambulatory children with severe neuromuscular scoliosis (NMS). Methods : Forty-one patients were retrospectively examined and subdivided corresponding to ilium hook fixation or SAI screws. The major curve correction (%) and pelvic obliquity (PO) correction (%) were assessed utilizing scoliosis plain film radiographs over time. Complications and unplanned return to the operating room (UPROR) were recorded. Patient-specific pre- and postoperative values were included in a backward stepwise regression model to assess UPROR. Results : Mean age at index intervention was 9.4 years. Preoperative main curve was 81° and PO was 22°. 21 and 20 patients were categorized into the SH and SAI subgroups, respectively. Initial curve correction was significantly better in the SAI subgroup (63 vs. 42% in the SH, p = 0.045), while PO correction was equally good. Curve and PO correction were maintained throughout the follow-up period of 55 months. UPROR rate was 38% in the SH subgroup, and 5% in the SAI subgroup ( p = 0.010). Regression analysis identified postoperative curve correction as predictive value for UPROR ( p = 0.006). Conclusions : SAI screw fixation has a low UPROR rate and achieves superior curve correction. S-hooks are a viable option to correct PO and NMS in children with high operative risk to reduce operative time, but revision surgery is not uncommon.