First-time shoulder dislocation: High prevalence of labral injury and age-related differences revealed by MR arthrography.
OBJECTIVE
To evaluate abnormalities and age-related differences after first-time shoulder dislocation.


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).


CONCLUSIONS
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.
Antonio
Gregory E
GE
Department of Diagnostic Radiology and Organ Imaging, Chinese University of Hong Kong.
Griffith
James F
JF
Yu
Alfred B
AB
Yung
Patrick S H
PS
Chan
Kai Ming
KM
Ahuja
Anil T
AT
D000328:Adult; D001175:Arthrography / Q000379:methods*; D001842:Bone and Bones / Q000378:metabolism; D015331:Cohort Studies; D003287:Contrast Media / Q000494:pharmacology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D015995:Prevalence; D011522:Protons; D017006:Rotator Cuff / Q000473:pathology; D012783:Shoulder Dislocation / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D012785:Shoulder Joint / Q000473:pathology
D003287:Contrast Media; D011522:Protons