Spinal sagittal alignment and postoperative adding-on in patients with adolescent idiopathic scoliosis after surgery

Introduction: Surgery for patients with adolescent idiopathic scoliosis (AIS) may change spinal sagittal alignment, and postoperative adding-on may affect spinal sagittal balance after reconstruction. This study was to investigate the effect of surgery on spinal sagittal alignment and the relationship between postoperative adding-on and spinal sagittal balance in patients with AIS. Hypothesis: The hypothesis of this study was that the effect of surgery on AIS was associated with recovery of the spinal sagittal plane and that presence of postoperative adding-on might affect the spinal sagittal balance. Materials and methods: This retrospective study enrolled 22 patients who received surgical treatment. Clinical, imaging and follow-up data were analyzed. Results: After surgery, T1 slope (T1S) and thoracic kyphosis (TK) were significantly (P