title: A comparison of magnetic resonance arthrography and arthroscopic findings in the assessment of anterior shoulder dislocations.
abstract: OBJECTIVE
  The aim of this study is to establish the sensitivity and specificity of MRA in the investigation of patients with traumatic anterior shoulder dislocations.
  
  
  METHODS
  A retrospective analysis of consecutive patients undergoing both magnetic resonance arthrography and arthroscopic assessment after a traumatic anterior shoulder dislocation between January 2011 and 2014 was performed. Demographic data were collected from electronic records. Images were interpreted by 8 musculoskeletal radiologists and patients were treated by 8 consultant orthopaedic surgeons. Arthroscopic findings were obtained from surgical notes and these findings were used as a reference for MRA. The sensitivity, specificity, and positive predictive value were calculated for the different injuries.
  
  
  RESULTS
  Sixty-nine patients underwent both an MRA and shoulder arthroscopy during the study period; however, clinical notes were unavailable in 9 patients. Fifty-three patients (88 %) were male, the mean age was 28 years (range 18 to 50) and 16 subjects (27 %) had suffered a primary dislocation. The overall sensitivity and specificity of MRA to all associated injuries was 0.9 (CI 0.83-0.95) and 0.94 (CI 0.9-0.96) retrospectively. The lowest sensitivity was seen in osseous Bankart 0.8 (CI 0.44-0.96) and superior labral tear (SLAP) lesions 0.5 (CI 0.14-0.86). The overall positive predictive value was 0.88 (CI 0.76-0.91) with the lowest values found in rotator cuff 0.4 (CI 0.07-0.83) and glenohumeral ligament (GHL) lesions 0.29 (CI 0.05-0.7).
  
  
  CONCLUSIONS
  Magnetic resonance angiography has a high sensitivity when used to identify associated injuries in shoulder dislocation, although in 8 patients (13 %) arthroscopy identified an additional injury. The overall agreement between MRA and arthroscopic findings was good, but the identification of GHL and rotator cuff injuries was poor.
authors.affiliation: Birmingham Heartlands Hospital, Bordesley Green East, Birmingham, B9 5SS, UK, Robert.jordan@doctors.org.uk.
authors.forename: R W
authors.initials: RW
authors.lastname: Jordan
authors.forename: R
authors.initials: R
authors.lastname: Naeem
authors.forename: K
authors.initials: K
authors.lastname: Srinivas
authors.forename: G
authors.initials: G
authors.lastname: Shyamalan
mesh_terms: D000293:Adolescent; D000328:Adult; D001182:Arthroscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012783:Shoulder Dislocation / Q000473:pathology*; D055815:Young Adult