title: The three-dimensional glenoid vault model can estimate normal glenoid version in osteoarthritis.
abstract: Glenohumeral arthroplasty can involve correcting pathologic glenoid tilt or version. Predicting the physiologic glenoid version for a particular individual can be difficult. We propose using a previously validated, 3-dimensional, glenoid vault model as a template to predict normal glenoid version. Computed tomography scans of both shoulders were obtained in 14 subjects with unilateral glenohumeral osteoarthritis. Custom-developed graphic software was used to create a 3-D reconstruction of each scapula. Within the software, the vault model was placed in a best-fit orientation into each glenoid vault independently by 3 observers who were blinded to the contralateral scapula. Measurement differences between the glenoid and vault model were analyzed by repeated-measures analysis of variance. Standard errors of measurement (SEM) were calculated. Interobserver and intraobserver reliabilities were assessed. The healthy glenoid version averaged -7.0 degrees (SEM, 0.7 degrees ; range, 0 degrees to -14 degrees ). The arthritic glenoid version averaged -15.6 degrees (SEM, 0.7 degrees ; range, 1 degrees to -33 degrees ; P < .0001). The version of the implanted vault model measured -7.1 degrees (SEM, 0.7 degrees ; range, -1 degrees to -15 degrees ) on the healthy side and -7.2 degrees (SEM, 0.7 degrees ; range -2 degrees to -11 degrees ) on the arthritic side. Measurements between observers were not significantly different (P = .98). Interobserver and intraobserver correlation coefficients were 0.79 (P < .001) and 0.80 (P < .001). In the arthritic glenoid, the vault model reproducibly closely approximated the version of the normal contralateral glenoid, -7.2 degrees vs -7.0 degrees (P = .99) and is a novel and accurate method of estimating the normal glenoid version. This technique may be valuable in correcting pathologic glenoid version due to arthritis.
authors.affiliation: The CORE Institute, Sun City West, AZ, USA. jason.scalise@thecoreinstitute.com
authors.forename: Jason J
authors.initials: JJ
authors.lastname: Scalise
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Codsi
authors.forename: Jason
authors.initials: J
authors.lastname: Bryan
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Iannotti
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008875:Middle Aged; D008953:Models, Anatomic; D008954:Models, Biological; D010003:Osteoarthritis / Q000000981:diagnostic imaging / Q000503:physiopathology*; D012540:Scapula / Q000000981:diagnostic imaging / Q000503:physiopathology; D012785:Shoulder Joint / Q000503:physiopathology*; D014057:Tomography, X-Ray Computed