Analyzing Factors Associated with Postoperative Shoulder Imbalance in Lenke2 Adolescent Idiopathic Scoliosis (Retrospective Cohort Study).

To assess the incidence of postoperative shoulder imbalance (PSI) following posterior spinal fusion surgeries in adolescent idiopathic scoliosis (AIS) with Lenke2 and calculate the risk factors for PSI. Sixty patients who underwent surgery for Lenke2 AIS with more than 2-year follow-up were selected. Radiographic parameters were measured before and after surgery, and at the latest follow-up. The patients were divided into PSI and non-PSI groups, with PSI defined as a radiographic shoulder height >15 mm on postoperative radiography. The factors were compared between the PSI and non-PSI groups using the Mann-Whitney U test or chi-squared test. Finally, explanatory variables were chosen for multivariate analysis based on previous studies. The PSI group comprised 17 patients. Most PSI cases spontaneously improved, and four patients (6.7%) showed PSI at the final follow-up. Univariate analysis indicated significant differences between postoperative T1 tilt (9.00 ± 5.17 vs. 5.67 ± 4.02, P = 0.029), UIV tilt (1.94 ± 4.49 vs. −1.00 ± 5.04, P = 0.039), and ΔT1 tilt (4.82 ± 3.99 vs. 2.12 ± 3.77, P = 0.026). Multivariate logistic regression analysis indicated that ΔT1 tilt had a significant positive relationship with PSI occurrence (coefficient = 0.2541, 95% confidence interval [CI]: 0.023 to 0.485, P = 0.0310). This study found no significant differences in the SRS-22 scores at the final follow-up. The incidence of PSI for Lenke2 AIS was 28.3% at 1 week postoperatively and 6.7% at the final follow-up. ΔT1 tilt was a risk factor for PSI. Adjustment of the T1 tilt during surgery was considered useful for the prevention of PSI. [ABSTRACT FROM AUTHOR]