Glenohumeral ligaments and shoulder capsular mechanism: Evaluation with MR arthrography

PURPOSE: To evaluate the efficacy of magnetic resonance (MR) arthrography in identification of the glenohumeral ligaments (GHLs) and to determine the location of abnormalities of the GHL, joint capsule, and labrum. MATERIALS AND METHODS: MR arthrograms were evaluated retrospectively in 46 patients with a history of shoulder instability, impingement syndrome, or pain of unknown cause. Imaging findings were correlated with surgical observations. RESULTS: The superior, middle, and inferior GHLs were identified on MR arthrograms in 39 (85%), 39 (85%), and 42 (91%) of the 46 patients, respectively. In diagnosis of tears of the superior, middle, and inferior GHLs, MR arthrography had a sensitivity of 100%, 89%, and 88% and a specificity of 94%, 88%, and 100%, respectively. CONCLUSION: Findings at MR arthrography can help accurate identification and demonstration of the integrity of the GHL and labrum and can help in staging of abnormalities. The large number of abnormalities depicted in the middle and inferior GHLs suggests that both might be important in the maintenance of glenohumeral joint congruity.