title: Recurrent anterior glenohumeral instability: the quantification of glenoid bone loss using magnetic resonance imaging.
abstract: OBJECTIVE
  To investigate the accuracy of conventional magnetic resonance imaging (MRI) in determining the severity of glenoid bone loss in patients with anterior shoulder dislocation by comparing the results with arthroscopic measurements.
  
  
  METHODS
  Institutional review board approval and written consent from all patients were obtained. Thirty-six consecutive patients (29 men, seven women; mean age, 34.5 [range, 18-55] years) with recurrent anterior shoulder dislocation (≥3 dislocations; mean, 37.9; range, 3-200) and suspected glenoid bone loss underwent shoulder MRI before arthroscopy (mean interval, 28.5 [range, 9-73] days). Assessments of glenoid bone loss by MRI (using the best-fit circle area method) and arthroscopy were compared. Inter- and intrareader reproducibility of MRI-derived measurements was evaluated using arthroscopy as a comparative standard.
  
  
  RESULTS
  Glenoid bone loss was evident on MRI and during arthroscopy in all patients. Inter- and intrareader correlations of MRI-derived measurements were excellent (intraclass correlation coefficient = 0.80-0.82; r = 0.81-0.86). The first and second observers' measurements showed strong (r = 0.76) and moderate (r = 0.69) interreader correlation, respectively, with arthroscopic measurements.
  
  
  CONCLUSIONS
  Conventional MRI can be used to measure glenoid bone loss, particularly when employed by an experienced musculoskeletal radiologist.
authors.affiliation: Fleury Medicina e Saúde and Instituto Nacional de Traumatologia e Ortopedia, Rua Soriano de Souza 98, Rio de Janeiro, RJ, Brazil, 20.511-180, pat_martins@ig.com.br.
authors.forename: Patrícia Martins
authors.initials: PM
authors.lastname: e Souza
authors.forename: Bruno Lobo
authors.initials: BL
authors.lastname: Brandão
authors.forename: Eduardo
authors.initials: E
authors.lastname: Brown
authors.forename: Geraldo
authors.initials: G
authors.lastname: Motta
authors.forename: Martim
authors.initials: M
authors.lastname: Monteiro
authors.forename: Edson
authors.initials: E
authors.lastname: Marchiori
mesh_terms: D000293:Adolescent; D000328:Adult; D001182:Arthroscopy / Q000379:methods; D001862:Bone Resorption / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000150:complications / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D012008:Recurrence; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D012782:Shoulder / Q000473:pathology*; D012783:Shoulder Dislocation / Q000150:complications / Q000473:pathology*; D012785:Shoulder Joint / Q000473:pathology*; D055815:Young Adult