The Prevalence of Glenohumeral Osteoarthrosis in Unstable Shoulders *

Background Glenohumeral osteoarthritis has been a well-described complication of open procedures to correct shoulder instability. What remains unknown is whether chondral injuries sustained during instability episodes contribute to osteoarthritis or whether the cause is primarily the stabilization procedure itself. Purpose To determine the prevalence of osteoarthrosis in a large database of patients with acute and chronic shoulder instability before primary stabilization surgery. Study Design Retrospective review of prospectively collected data. Methods Surgical and demographic data were collected on 422 patients with a diagnosis of shoulder instability who underwent arthroscopic examination and shoulder stabilization. Results There was a significant association between the grade of osteoarthrosis and the presence of osteoarthritis (grade III or IV chondral damage) with time from injury to surgery. Patients with osteoarthritis were significantly older than those without (34.9 versus 29.6 years). Multivariate analysis identified older age and time from injury to surgery as independent predictors of osteoarthritis. We found no association between direction of instability and the presence of osteoarthritis. Conclusion The overall prevalence of glenohumeral osteoarthrosis was low. Predictors of osteoarthritis included time from injury to surgery and age.