Objective To identify risk factors associated with postoperative shoulder joint dysfunction in patients who underwent surgical intervention for acromioclavicular (AC) joint dislocation, with the aim of enhancing preoperative counselling, surgical planning, and postoperative management to optimize functional outcomes. Methods Patients who underwent surgery for AC joint dislocation between January 2018 and January 2023 at a hospital orthopaedic centre were enrolled into this retrospective study. Inclusion criteria were patients aged ≥18 years with a documented AC joint dislocation who underwent surgical treatment and had a minimum follow-up period >1 year. Patients with pre-existing shoulder conditions, prior shoulder surgeries, or incomplete medical records were excluded. Visual Analog Scale pain score ≥5 and Constant-Murley Score ≤70 was considered indicative of shoulder joint dysfunction. Statistical analyses included univariate and multivariate logistic regression to identify independent risk factors for postoperative shoulder joint dysfunction. Results Among 208 included patients, 56 (27%) exhibited shoulder joint dysfunction at the final follow-up. High-energy injury mechanisms, combined coracoclavicular ligament injuries, and lack of coronal plane congruity were identified as significant predictors of postoperative dysfunction. Specifically, high-energy injuries (odds ratio [OR] 5.493, 95% confidence interval [CI] 2.068, 14.590), combined coracoclavicular ligament injuries (OR 0.118, 95% CI 0.032, 0.432), and lack of coronal plane congruity (OR 2.540, 95% CI 1.197, 5.387) were associated with an increased risk of poor shoulder function postoperatively. Other factors, such as age, injury mechanism, and postoperative exercise compliance also contributed to the outcomes. Level of evidence: iv. Conclusions Injury mechanism, ligamentous injuries, and joint congruity are important in determining postoperative shoulder function. Accurate joint reduction and diligent postoperative rehabilitation are crucial for optimal recovery. These findings provide valuable insights for improving patient care and surgical outcomes in AC joint dislocation treatment. Further research is needed to validate these findings and explore additional factors that may influence postoperative shoulder function.
