A CT-Based Study of Glenoid Version in Patients with Frozen Shoulder

Background: Glenoid version is a key morphometric parameter influencing glenohumeral joint biomechanics, stability, and load distribution. Alterations in glenoid orientation, particularly increased retroversion, have been implicated in abnormal joint kinematics, posterior humeral head translation, and degenerative shoulder conditions. While glenoid version has been extensively studied in normal and arthritic shoulders, its role in frozen shoulder (adhesive capsulitis) remains inadequately explored, especially in relation to repetitive overhead activity. Aim: To evaluate glenoid version in patients with frozen shoulder using computed tomography (CT) and to analyze its association with dominance and overhead activity. Materials and Methods: This observational study included 40 patients clinically diagnosed with frozen shoulder. Glenoid version was measured on axial CT images using the Friedman method. Comparisons were made between dominant and non-dominant shoulders and between patients with and without a history of repetitive overhead activity. Statistical analysis was performed using SPSS, with results expressed as mean, standard deviation, and p-values. Results: The mean glenoid version was −10.9 ± 3.4°, indicating overall retroversion. Increased retroversion (>10°) was observed in 45% of patients. Glenoid retroversion was significantly greater in patients with overhead activity compared to those without (p < 0.001) and on the dominant side compared to the non-dominant side (p = 0.002). Conclusion: Increased glenoid retroversion is common in frozen shoulder patients, particularly in those with dominant-side involvement and repetitive overhead activity, suggesting a possible biomechanical contribution to disease pathology. Keywords: Glenoid version, glenoid fossa, retroversion, observational study.