Assesment of Coracoid Inclination Angle and Coracoacromial Arch Angle on MRI in Rotator Cuff Tears

Objective: The purpose of this study was to investigate the role of the coracoid inclination angle and the coracoacromial arch angle in the etiology of rotator cuff tears on magnetic resonance imaging. Material and Methods: A total of 102 shoulder magnetic resonance imaging taken in our clinic between January 2014 and January 2019 were retrospectively evaluated. Supraspinatus tendon was evaluated for partial tear and full tear. The coracoid inclination angle and the coracoacromial arch angle were measured in all cases. Independent t test was used for comparisons between groups. Pearson correlation analysis was performed between the coracoid inclination angle and the coracoacromial arch angle. Results: There were 29 female and 24 male patients in the rotator cuff tear group and the mean age was 49.5±11.3 years. There were 21 female and 28 male patients in the control group and the mean age was 45.08±11.7 years. In the rotator cuff tear group; the mean coracoid inclination angle was 92.8±8o and the mean coracoacromial arch angle was 127.4±7.3o. In the control group; the mean coracoid inclination angle was 106.5±9.5o and the mean coracoacromial arch angle was 122.4±5o. A statistically significant difference was found between the groups for both angle values (p <0.05). Conclusion: The coracoid inclination angle was narrower and the coracoacromial arch angle was wider in rotator cuff tear cases. Coracoid process morphology and related variable coracoid inclination angle, coracoacromial arch angle may be the predisposing factors for rotator cuff tears and may be used to help determine the etiology of rotator cuff pathologies