Changes of shoulder balance, sagittal alignments, and curve correction in the treatment of Lenke 1 and 2 adolescent idiopathic scoliosis using a three-dimensional-based correction strategy in correlation to health-related quality of life using the Scoliosis Research Society-22 Questionnaire

Background: Shoulder balance in Lenke 1 and 2 adolescent idiopathic scoliosis (AIS) is a complex condition without a reliable strategy to achieve full correction. Moreover, none reported health-related quality of life of surgically treated Lenke 1 and 2 suffering severe AIS patients before and after the surgery. Subjects and Methods: Preoperative standing, side bend, and postoperative Cobb angles were analyzed to determine the relationship between shoulder balance, curve flexibility, and correction rates. The sagittal alignment was analyzed in these patients by cervical lordosis (CL) (C2–C7), thoracic kyphosis (TK) (T1–T12), lumbar lordosis (LL) (L1-S1), pelvic incidence, pelvis tilt, sacral slope, and C7 sagittal vertical axis (SVA). All recruited patients completed the Scoliosis Research Society-22 questionnaire before, after surgery, and follow-up. Results: There were 26 Lenke 1 and 2 severely AIS patients recruited in this study. The shoulder balance changed from left down to the left up after the operation as reflected by the changes in T1tilt (medial shoulder) and clavicular angles (lateral shoulder). The sagittal alignment changes of this group of patients moved toward increased CL, TK, and LL and an SVA toward zero. “Function” and “Self-image” were significantly improved after surgery, particularly in female Lenke 2 patients regardless of age. Conclusions: The sagittal alignment changes of this group of patients moved toward increased CL, TK, LL and SVA toward zero. “Function” and “Self-image” were significantly improved after the surgery. Sex and age-specific analysis showed that female Lenke 2 AIS patients were the group of patients showing the improvements regardless of age at operation.