Staged versus single-stage traditional growing rod implantation in severe early-onset scoliosis: complications and radiographic outcomes.

Abstract

To compare staged, foundation-first (anchor-first) versus single-stage (same-day) traditional growing rod (TGR) implantation for early-onset scoliosis (EOS), with a prespecified focus on severe deformity and/or thoracic hyperkyphosis. In this single-center cohort study, we performed a retrospective analysis of prospectively collected data from EOS patients treated with TGR. The primary outcome was the proportion of patients with at least one complication requiring unplanned surgery during growing-rod treatment (excluding post-final fusion surgeries). Radiographic outcomes were assessed at early postoperative (PO1mo) and final follow-up. A prespecified severe cohort was defined as preoperative max Cobb > 100° and/or thoracic kyphosis (T2-T12) ≥ 60°. Fifty-four patients were included (same-day n = 39; staged n = 15), including 18 severe-eligible patients (same-day n = 6; staged n = 12). In the overall cohort, complications requiring unplanned surgery were similar between same-day and staged implantation (same-day 33.3% vs. staged 26.7%; RR 0.80; P = 0.751). In the severe cohort, staged implantation was associated with fewer complications requiring unplanned surgery (same-day 83.3% vs. staged 25.0%; RR 0.30; P = 0.043) and fewer total complication events per patient (P = 0.005). Radiographic correction and growth at PO1mo and final follow-up were comparable between strategies in the severe cohort. Staged anchor-first TGR implantation was associated with fewer complications requiring unplanned surgery in the prespecified severe cohort, with comparable radiographic outcomes. These hypothesis-generating findings support further evaluation of staged implantation as a selective strategy for severe EOS in larger multicenter cohorts. III.