First‐time shoulder dislocation: High prevalence of labral injury and age‐related differences revealed by MR arthrography

Purpose To evaluate abnormalities and age‐related differences after first‐time shoulder dislocation. Materials and Methods MRA images of first‐time dislocators were assessed for labral‐ligamentous‐capsular / rotator cuff abnormalities and analyzed the age‐related differences (< and ≥30 years old). Results Sixty‐six patients (34 <30 years old vs. 32 ≥30 years; 51 males; all anterior dislocations) were imaged. Forty‐eight patients (73%) showed anteroinferior labral avulsion, consisting of: 6% (4/34 vs. 0/32) Perthes; 23% (8/34 vs. 7/32) free ALPSA (anterior labrum periosteal sleeve avulsion) lesion); 6% (1/34 vs. 3/32) adherent ALPSA; 23% (9/34 vs. 6/32) Bankart; 14% (5/34 vs. 4/32) inferiorly displaced avulsed labrum; 2% (1/34 vs. 0/32) GLAD. Extensive labral detachment (extended above 3 o'clock position) was present in 31% (11/28 vs. 4/20). There were 14% (6/34 vs. 3/32) superior labrum anterior‐posterior (SLAP) lesion; 27% (1/34 vs. 17/34) rotator cuff tendon tear; 71% (25/34 vs. 22/32) Hill‐Sachs defect. Young patients were more likely to have extensive labral avulsions ( P = 0.054), but less likely to have rotator cuff tears ( P < 0.001). Conclusion A high prevalence and wide variety of labral avulsions after first‐time shoulder dislocation, especially adherent ALPSA, inferiorly displaced avulsed labrum, or GLAD lesion, may influence treatment choice and outcome, suggesting a role for early MRA to assist in treatment triage. J. Magn. Reson. Imaging 2007;26:983–991. © 2007 Wiley‐Liss, Inc.