Morphology and deformity of the shoulder and pelvis in the entire spine radiographs of adolescent idiopathic scoliosis

BACKGROUND: To investigate the deformity and asymmetry of the shoulder and pelvis in adolescent idiopathic scoliosis (AIS) patients. METHODS: This retrospective cross-sectional study enrolled 223 AIS patients with a right thoracic curve or left thoracolumbar/lumbar curve who underwent spine radiographs at the Third Hospital of Hebei Medical University between November 2020 and December 2021. The following parameters were measured: Cobb angle, clavicular angle, glenoid obliquity angle, acromioclavicular joint deviation, femoral neck-shaft projection angle, iliac obliquity angle, acetabular obliquity angle, coronal trunk deviation distance, and spinal deformity deviation distance. The Mann–Whitney U test, Kruskal–Wallis H test were used for inter-group comparisons, and Wilcoxon signed-rank test were used for intra-group left and right sides comparisons. RESULTS: Shoulder and pelvic imbalances were found in 134 and 120 patients, respectively, and there were 87, 109, and 27 cases of mild, moderate, and severe scoliosis, respectively. Compared with mild scoliosis patients, the difference in the acromioclavicular joint offset on bilateral sides was significantly increased in moderate and severe scoliosis [11.04, 95% confidence interval (CI): 0.09–0.14 for mild, 0.13–0.17 for moderate, and 0.15–0.27 for severe scoliosis, P=0.004], and the difference in the femoral neck-shaft projection angle on bilateral sides was significantly enhanced with scoliosis aggravation (14.14, 95% CI: 2.34–3.41 for mild, 3.00–3.94 for moderate, and 3.57–6.43 for severe scoliosis, P=0.001). The acromioclavicular joint offset was significantly larger on the left than that on the right in patients with a thoracic curve or double curves (thoracic curve −2.75, 95% CI: 0.57–0.69 for the left and 0.50–0.63 for the right, P=0.006; double curve −3.27, 95% CI: 0.60–0.77 for the left and 0.48–0.65 for the right, P=0.001). The femoral neck-shaft projection angle was significantly larger on the left than right in patients with a thoracic curve (−4.46, 95% CI: 133.78–136.20 for the left and 131.62–134.01 for the right, P<0.001), but larger on the right than left in patients with thoracolumbar/lumbar curve (thoracolumbar −2.98, 95% CI: 133.75–136.70 for the left and 135.13–137.82 for the right, P=0.003; lumbar −3.24, 131.97–134.56 for the left and 133.76–136.26 for the right, P=0.001). CONCLUSIONS: In AIS patients, shoulder imbalance has a greater impact on coronal balance and spinal scoliosis above the lumbar segment, whereas pelvic imbalance has a greater impact on sagittal balance and spinal scoliosis below the thoracic segment.