Association Between Acromion Morphology and Non-Traumatic Rotator Cuff Injury Among Young Adult Filipinos in a Tertiary Hospital: Cross-sectional Study

Introduction Rotator cuff injury (RCI) is among the most common shoulder pathologies, significantly affecting quality of life. Acromial morphology has been implicated as a predisposing factor, but limited local data exist. The Bigliani-Kitay classification defines four acromion types: flat (I), curved (II), hooked (III), and convex (IV). MRI is the preferred modality for assessing both acromial morphology and RCI. Objective To assess the association between acromion morphology and RCI among patients undergoing shoulder MRI at Makati Medical Center, a tertiary hospital in the Philippines. Methods A retrospective review of shoulder MRI scans performed from January to December 2019 was conducted. Patients with shoulder pain were included as cases. Acromion morphology and presence of RCI (tendinosis, partial, or full-thickness tears) were documented. Images were interpreted by radiologists accredited by the Philippine College of Radiology. Results Of 132 patients (mean age: 31.2 ± 5.4 years), 65.9% were male. The period prevalence of RCI was 58.3% (n = 77). There was no significant sex-based difference in RCI prevalence ( p = 0.4036). RCI was significantly associated with Type II (70.5%, p < 0.00001) and Type III (100%, p = 0.00158) acromion morphologies. No significant association was found for Types I and IV. Conclusion Type II and Type III acromial morphologies are significantly associated with higher prevalence of RCI. Recognition of these morphologies on MRI may help identify patients at increased risk and allow for early intervention.