DOS 2018

238 · DOS Abstracts Distraction-to-stall ensures spinal growth in Magnetically Controlled Growing Rods. Casper Dragsted, Dahl Benny, Søren Ohrt-Nissen, Thomas Andersen, Martin Gehrchen Spine Unit, Orthopaedic Surgery, Rigshospitalet and University of Copenhagen; Department of Orthopedics and Scoliosis Surgery, Texas Children’s Hospital and Baylor College of Medicine, TX, USA Background: Various distraction protocols have been reported for Magnetically Controlled Growing Rods (MCGR) in the treatment of early-onset scoliosis. Recent studies show a discrepancy between intended distraction and true dis- traction length which underlines the need for a simple and reliable distraction protocol. Purpose / Aim of Study: Examine the efficacy of standardized protocol with intended distraction-to-stall by assessing spinal growth and distraction length in patients treated with MCGR. Materials and Methods: Retrospective study of a single-center cohort. Patients treated with dual MCGR and minimum 3 distractions were included. Conversion cases were excluded. Distractions were performed with intervals of 2-3 months and the intention of distracting-to-stall on both rods. Distraction length and curve correction were monitored on x-rays every 6 months. Spinal growth was assessed using T1-T12 and T1-S1 height. Findings / Results: 19 patients (8 idiopathic and 11 non-idiopathic) were in- cluded. Mean age at surgery was 9.7±1.9 years and median follow-up was 2.2 years [IQR 1.8-2.6]. Major curve improved from median 76° preoperatively [IQR 64-83] to 42° postoperatively [IQR 32-51] (p<0.001) corresponding to a curve correction of 43% [IQR 33-51]. Correction was maintained at 1 and 2-year follow-up. Median annual T1-T12 and T1-S1 length increased 7 mm [IQR 5-12] and 9 mm [IQR 5-17] respectively. 194 distraction procedures were performed; 78% of these were distracted-to-stall and 22% were stopped at discomfort. Median annual rod distraction was 9.3 mm [IQR 6.2-12.5] for the concave side and 8.3 mm [IQR 6.2-10.7] for the convex side. Five patients had implant- related complications leading to unplanned re- operations in 4 pa- tients. Conclusions: A distraction-to-stall procedure ensures spinal growth with com- plication rates comparable to the available literature. 179.