Which radiological parameters of the coracoid process influence the diagnosis of atraumatic subscapularis tears? Systematic review and meta-analysis

Abstract Introduction Accurate diagnosis of subscapularis tears remains challenging due to the limitations of physical examinations and imaging techniques. Therefore, specific radiological parameters have been proposed as predictors of atraumatic subscapularis tears to improve diagnostic sensitivity and accuracy. These parameters include coracohumeral distance (CHD), coracoglenoid angle (CGA), coracoid angle (CA), coracoid overlap (CO), and coracohumeral angle (CHA). However, well-accepted cutoff values are still lacking, and there is no consensus on its clinical usefulness. Materials and methods The PubMed, Scopus, and Cochrane Library databases were queried in July 2024. Inclusion criteria focused on studies that reported MRI-based radiological measurements of the coracoid process in patients with subscapularis tears versus controls. A meta-analysis was performed to evaluate outcomes, with data reported as raw mean difference (MD) and 95% confidence interval (CI). Results Fourteen studies involving 1,692 patients with subscapularis tears and 1,648 controls were included. Significant findings include a smaller axial CHD in the subscapularis tear group compared to controls (MD, − 1.67; 95% CI, − 2.61 to − 0.72; P = 0.002). The sagittal CHD was also reduced in the tear group (MD, − 1.43; 95% CI, − 1.89 to − 0.98; P < 0.0001). The CGA was (MD, − 1.15; 95% CI, − 2.20 to − 0.10; P = 0.032), and the CA was also reduced (MD, − 18.63; 95% CI, − 35.60 to − 1.66; P = 0.042). The CO showed no significant difference between the tear and control groups (MD, 1.68; 95% CI, − 1.27 to 4.62; P = 0.21). In contrast, the CHA was increased in the tear group (MD, 3.71; 95% CI, 2.32–5.11; P < 0.01). Conclusion Several radiological parameters, including CA, CHA, CGA, and axial and sagittal CHD, demonstrated statistically significant differences between patients with and without atraumatic subscapularis tears. Among them, CHA appears to be the most promising due to its consistent association and low heterogeneity. However, substantial variability across studies and limited data for certain parameters underscore the need for further prospective research to validate their diagnostic value and establish standardized imaging protocols. Study Design Systematic review and meta-analysis; Level of evidence, III.