Anterior Shoulder Dislocation: Evaluation with MR and MR Arthrography

Objective To summary the MR findings of anterior shoulder dislocation. Methods The routine MR images and MR arthrography images of 26 patients with anterior shoulder dislocation or recurrent dislocation were retrospectively analyzed. The emphasis was focused on the bone structure of the shoulder, the anteroinferior labrum, and the anterior capsular insertion type.Results The Hill sachs lesion was found in 77%(20/26)patients and abnormality of the anteroinferior labrum (Bankart lesion) was seen in 88%(23/26). Type II and type III capsular insertions were only found in 19%(5/26)of all patients, and the presence of osseous bankart lesion was only 8%(2/26). In revealing the abnormalities of the labrum and capsular, MR arthrography was superior to routing MR. Conclusion The main MR appearances of anterior shoulder dislocation were abnormalities of the anterior labrums and Hill sachs lesions. MR arthrography is more helpful to diagnose the abnormalities of anteroinferior labrum than routing MR examination.