Operative time was an average of seven hours 35 minutes. Perioperative bleeding was an average of 3,900 ml. The length of stay was an average of 65 days. Correction of Sagittal Vertical Axis (SVA), lumbar lordosis (LL), Pelvic Tilt (PT) and C7-coronal center vertical line (C7-CVL) was achieved in all patients. However, in the inferior thoracic group, sagittal radiographs demonstrated progression of PJK, increased SVA, and pelvic tilt between the measurements taken immediately after surgery and those taken at final follow-up. In this group complications such as pseudarthrosis, PJK, cage dislodgement, rod breakage and infection were also noted. Postoperative complications requiring multiple surgeries were encountered in all cases of the inferior thoracic group. By contrast, in the superior thoracic group, although minor complications such as skin ulcers were encountered, posture correction was maintained, postoperative SRS scores remained good, and a high satisfaction rate was obtained without multiple operations.