Computer-assisted skip pedicle screw fixation for adolescent idiopathic scoliosis

Study design: A retrospective single-center and single-surgeon study. Objectives: This study investigated the clinical and radiological results of skip pedicle screw fixation for adolescent idiopathic scoliosis (AIS). Summary of background data: At present, the generally used technique for pedicle screw fixation for the surgical correction of AIS entails inserting a pedicle screw into every segment on the corrective side and into every or every other segment on the supportive side. To reduce operation time, blood loss, and cost, we developed skip pedicle screw fixation to achieve correction of AIS using fewer pedicle screws. Methods: We evaluated 62 consecutive patients who had undergone computer-assisted skip pedicle screw fixation from August 2005 to June 2014. All patients were followed up for at least two years. We investigated the clinical results of skip pedicle screw fixation for AIS. Results: The mean number of fused vertebrae was 10.3 +/- 2.0, the mean surgical time was 242 +/- 78 min, and the mean blood loss volume was 1060 +/- 688 ml. The mean Cobb angle of main thoracic (MT) curve two years after surgery improved significantly compared with that before surgery (p < 0.01). The mean correction rate of MT curve immediately after surgery was 62.4 +/- 12.4% and correction loss of MT curve at two years after surgery was 1.9 +/- 5.8 degrees. The SRS-22 subtotal score two years after surgery improved significantly compared to that before surgery (p < 0.01). Although no patients experienced major complications, eight (12.9%) encountered minor complications (two [3.2%] had massive blood loss [>3000 ml], three [4.8%] had a broken screw, one [1.6%] had a set-screw that dropped out, one [1.6%] experienced deep vein thrombosis, one [1.6%] experienced acute renal failure, and one [1.6%] experienced intercostal neuralgia). Revision surgery was not performed. Conclusions: Subjects with AIS who underwent skip pedicle screw fixation had significantly improved clinical and radiological parameters at two years after surgery, indicating that skip pedicle screw fixation could be used to successfully treat AIS. Level of evidence: Level 4 (C) 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.