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 anteroinferiro 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 cufftendon tear; 71% (25/34 vs. 22/32) Hill-Sachs defect. Yound 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.