Abstract
BACKGROUND: Rotator cuff tears (RCTs) are a prevalent cause of shoulder dysfunction, especially in older adults. Among the intrinsic and extrinsic factors influencing tear severity, the role of acromial morphology remains controversial. This study aims to investigate the association between acromion type, as classified by the Bigliani system, and RCT severity confirmed arthroscopically, and to assess whether age, diabetes mellitus, or hyperlipidemia are significant predictors. METHODS: In this retrospective, cross-sectional study, 96 patients who underwent shoulder magnetic resonance imaging (MRI) and subsequent arthroscopy between 2020 and 2024 were randomly selected. Patients were categorized based on Bigliani acromion types (Type I, II, III). RCT size was assessed and classified intraoperatively. Multinomial logistic regression was used to identify predictors of tear severity. RESULTS: A significant association was found between acromion morphology and tear size (p < 0.001). Type III (hooked) acromia were strongly associated with massive tears, while Type I and II were more commonly associated with smaller tears. Increasing age was an independent predictor of larger tears. No statistically significant relationship was found between tear size and diabetes mellitus or hyperlipidemia. CONCLUSIONS: Hooked (Type III) acromion morphology and older age were found to be associated with greater RCT severity. Systemic metabolic comorbidities such as diabetes and hyperlipidemia did not appear to significantly affect tear extent. These findings support the potential clinical relevance of acromial morphology in preoperative assessment and risk stratification, although further prospective research is warranted. STUDY DESIGN: Retrospective, cross-sectional, observational study.