Impact of Coracoacromial Ligament Thickness on Shoulder Impingement Syndrome: A Cross-Sectional Magnetic Resonance Imaging Study Publisher



Dehghan P ; Langari S ; Ghiasi F ; Majdifar M ; Hassabi M ; Dejban FF ; Moshrefiaraghi D
Source: Health Science Reports Published:2026

Abstract

Background and Aims: Shoulder impingement syndrome (SIS) is a common cause of shoulder pain and dysfunction. This study explored the association between coracoacromial ligament (CAL) thickness and SIS using magnetic resonance imaging (MRI). Methods: This cross-sectional MRI-based observational study involved 47 patients aged 18–70 years with shoulder pain. T2 fat-saturated sagittal MRI views were used to measure CAL thickness at proximal and distal portions by two radiologists. Statistical analyses included t-tests, χ2 tests, and Pearson's correlation, with significance set at p < 0.05. Results: Mean proximal CAL thickness was 1.24 mm (SD = 0.44 mm), and distal thickness was 1.50 mm (SD = 0.72 mm). Patients with SIS had significantly greater thickness at proximal (1.36 mm vs. 1.05 mm, p = 0.002, d = 0.82) and distal (1.78 mm vs. 1.12 mm, p = 0.001, d = 0.92, 95% CI: 0.39–0.93). Males showed greater distal thickness (1.62 mm) than females (1.34 mm, p = 0.04, d = 0.45). Age did not correlate with thickness (p > 0.71). Subacromial bursitis (70.21%, p < 0.001) and acromioclavicular (AC) joint osteophytes (68.09%, p = 0.003) were prevalent and associated with SIS. Conclusion: CAL thickness, particularly at the distal portion, was strongly associated with SIS, independent of age but varying by gender. Measuring CAL thickness may aid SIS diagnosis. © 2026 The Author(s). Health Science Reports published by Wiley Periodicals LLC.