title: Prevalence, pattern, and spectrum of glenoid bone loss in anterior shoulder dislocation: CT analysis of 218 patients.
abstract: OBJECTIVE
  The purpose of our study was to determine the prevalence, pattern, and spectrum of glenoid bone loss in anterior shoulder dislocation, to relate this to the frequency of dislocation, and to test the appropriateness of the measurement method.
  
  
  METHODS
  Two hundred eighteen patients with single or recurrent anterior shoulder dislocation underwent shoulder CT examination. Fifteen patients had bilateral dislocation. Prevalence and severity of glenoid bone loss and glenoid fracture were assessed. CT examinations of 56 control subjects without shoulder dislocation were evaluated for glenoid contour and side-to-side variation in glenoid width.
  
  
  RESULTS
  Glenoid bone loss was present in 27 (41%) of 66 patients with first-time unilateral dislocation and 118 (86%) of 137 patients with recurrent unilateral dislocation. Glenoid bone loss ranged from -0.3% to -33% (mean, -10.8% +/- 7.9%). Seventy-four (51%) of 145 patients had < or = 10% glenoid bone loss, 54 (37%) had between 10% and 20%, eight (6%) had between 20% and 25% glenoid bone loss, and nine (6%) had > or = 25% glenoid bone loss. Glenoid rim fractures were present in 49 (21%) of 233 dislocated shoulders. The number of dislocations correlated moderately with the severity of glenoid bone loss (r = 0.56). The normal side-to-side glenoid width variation was small (0.46 +/- 0.81 mm).
  
  
  CONCLUSIONS
  Glenoid bone loss is common in anterior shoulder dislocation. It is probably multifactorial in origin, is usually mild in degree, and has a maximum observed severity of -33%. Dislocation frequency cannot accurately predict the degree of bone loss.
authors.affiliation: Department of Diagnostic Radiology and Organ Imaging, The Chinese University of Hong Kong, Prince of Wales Hospital, 30-32 Ngan Shing St., Shatin, Hong Kong, SAR, China. griffith@cuhk.edu.hk
authors.forename: James F
authors.initials: JF
authors.lastname: Griffith
authors.forename: Gregory E
authors.initials: GE
authors.lastname: Antonio
authors.forename: Patrick S H
authors.initials: PS
authors.lastname: Yung
authors.forename: Eric M C
authors.initials: EM
authors.lastname: Wong
authors.forename: Alfred B
authors.initials: AB
authors.lastname: Yu
authors.forename: Anil T
authors.initials: AT
authors.lastname: Ahuja
authors.forename: Kai Ming
authors.initials: KM
authors.lastname: Chan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001862:Bone Resorption / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012307:Risk Factors; D012540:Scapula; D012720:Severity of Illness Index; D012783:Shoulder Dislocation / Q000150:complications / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed