How much postoperative shoulder imbalance is satisfactory for Lenke 1/2 adolescent idiopathic scoliosis patients?

Background: The recognition of shoulder imbalance in patients with adolescent idiopathic scoliosis (AIS) has garnered increasing attention among spine surgeons. Nevertheless, there is an inconsistency in the definitions of shoulder imbalance, and the relationships between radiological parameters and patient satisfaction remain inadequately explored. Objective: This study aimed to determine the correlated shoulder imbalance parameter leading to patient acceptable symptom state (PASS) for Lenke 1/2 AIS patients after correction surgery, based on Scoliosis Research Society-22r questionnaires. Methods: Lenke 1/2 type patients from 2 tertiary hospitals undergoing pedicle-screw fixation and correction surgery from 2017 to 2021 were enrolled. One patient who replied positively to both No. 21 and 22 questions was defined as achieving PASS. Basic patient information and shoulder imbalance parameters were calculated and compared pre-surgery and at follow-up (at least 24 months). Binary logistic regression analysis and receiver operating characteristic (ROC) curve were performed. Results: One hundred twenty-eight patients (99 females, mean age 14.8 years) were enrolled. A total of 105 (82.0%) achieved PASS. Clavicle-chest cage angle difference (CCAD) was an independent risk factor correlated with treatment satisfaction (odds ratio = 0.674, p = 0.01), with a cutoff value of 7.3° (area under the curve: 0.75, 95% CI: 0.655–0.846; sensitivity: 91.7% and specificity: 64.4%). Conclusions: In Lenke 1/2 AIS patients, there was a significant correlation between CCAD and the state of PASS. Patients were more inclined to be satisfied with surgical treatment when the CCAD was less than or equal to 7.3°.