title: Recurrent anterior shoulder instability.
abstract: The purpose of this study was to compare 2 radiographic methods for measuring anteversion and to determine whether glenoid anteversion is a significant factor in recurrence of instability after anterior repair. West Point axillary roentgenograms were obtained in 128 patients (138 shoulders) at a mean of 9 years after surgery. Two methods to measure glenoid anteversion were compared: The angle between the glenoid and the body of the scapula, and the angle between the glenoid and the posterior margin of the acromion. There was less variation in the measurements using the glenoid margin-posterior acromion angle. By this method, anteversion was 11 degrees +/- 4 degrees for the 15 patients with multiple (2 or more) recurrences, 8 degrees +/- 3 degrees for the 15 patients with 1 recurrence, and 6 degrees +/- 5 degrees for the 109 patients with no recurrences. Although these differences are statistically significant (P = 0.003), they probably are not clinically important because they are small (mean of only 5 degrees). The differences obtained by measuring the angle between the glenoid and the body of the scapula were not statistically significant.
authors.affiliation: University of Toronto, Ontario, Canada.
authors.forename: P A
authors.initials: PA
authors.lastname: Dowdy
authors.forename: S W
authors.initials: SW
authors.lastname: O'Driscoll
mesh_terms: D000174:Acromion / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D016009:Chi-Square Distribution; D006801:Humans; D007593:Joint Instability / Q000000981:diagnostic imaging* / Q000209:etiology / Q000601:surgery; D011859:Radiography; D012008:Recurrence; D012540:Scapula / Q000033:anatomy & histology / Q000000981:diagnostic imaging; D012785:Shoulder Joint / Q000033:anatomy & histology / Q000000981:diagnostic imaging*