Shoulder Instability: the Role of Mr Arthrography in Diagnosing Anteroinferior Labroligamentous Lesions Our Experience at King Hussein Medical Center

Objective: To determine the reliability and accuracy of magnetic resonance arthrography of the shoulder for the diagnosis of anteroinferior labroligamentous lesions in patients with gleno-humeral joint instability. Methodology: This retrospective study was performed at King Hussein Medical Center in Jordan. Twenty eight patients who underwent shoulder MR arthrogram and arthroscopy during a 22-month period were reviewed. All the twenty eight patients had history of previous shoulder dislocation and clinical suspicion of anteroinferior labroligamentous lesions and glenohumeral joint instability. The series included 24 males and 4 females. The mean average age of the patients was 29 years. All patients underwent shoulder MR arthrogram and the results of MR arthrogram were compared with the arthroscopic findings which were used as the reference standard. MR arthrograms were analyzed for the presence and type of labroligamentous injuries which include (Bankart, anterior labral periosteal sleeve avulsion [ALPSA], Perthes, glenolabral articular disruption [GLAD], or nonclassifiable lesion). Sensitivity, specificity & accuracy for the detection & classification of anteroinferior labroligamentous lesions with MR arthrography were calculated. Results: At arthroscopy, 21 anteroinferior labroligamentous lesions were diagnosed, including 15 Bankart lesions, three ALPSA lesions, two Perthes lesions and one GLAD lesion. Seven labral lesions were nonclassifiable at arthroscopy, all of which occurred after a history of chronic instability. When compared with arthroscopic findings, Shoulder MR Arthrography had two false-negative results (sensitivity, 92.8%) and no false-positive results. The sensitivity of shoulder MR Arthrography in detecting anteroinferior labroligamentous lesions was 92.8% (26/ 28) and specificity was (100%). The overall accuracy of Shoulder MR Arthrography in detecting labroligamentous lesions in this study was 90.5% (19/21). Conclusion: MR arthrography of the shoulder is reliable and accurate in classification of acute and chronic anteroinferior labroligamentous injuries.