Shoulder arthroplasty in patients with a prior anterior shoulder dislocation. Results of a multicenter study

Abstract

Background: Prior reports of shoulder arthroplasty performed for dislocation-induced arthropathy have included only patients who had had a prior stabilizing procedure. The purpose of this study was to report the results of shoulder arthroplasty in all patients with a prior anterior shoulder dislocation, including both those previously treated operatively and those previously treated nonoperatively.

Methods: Fifty-five shoulders undergoing arthroplasty for arthritis following a prior anterior shoulder dislocation were evaluated. Twenty-seven of the shoulders had undergone a prior anterior stabilization procedure. The measures used to evaluate the shoulders included the Constant score, adjusted Constant score, active mobility, subjective satisfaction, radiographic result, and complications.

Results: The shoulders were evaluated at a mean of 45.0 months. The Constant score improved from a mean of 30.8 points preoperatively to a mean of 65.8 points at the time of follow-up. The adjusted Constant score improved from a mean of 38.2% to a mean of 79.8%. Active forward flexion improved from a mean of 82.1 degrees to a mean of 138.9 degrees. Active external rotation improved from a mean of 4.0 degrees to a mean of 38.6 degrees. Fifty patients rated the result as good or excellent. Negative prognosticators included an older age at the time of the initial dislocation and a rotator cuff tear. No significant differences in demographic factors, pre-arthroplasty function, post-arthroplasty function, pre-arthroplasty radiographic findings, post-arthroplasty radiographic findings, complication rate, or reoperation rate were noted between the patients treated with a prior operation for the anterior instability and those treated nonoperatively.

Conclusions: This investigation documented the good results obtainable with shoulder arthroplasty for the treatment of arthritis following anterior shoulder instability. In addition, our findings suggest that capsulorrhaphy-induced arthropathy may be indistinguishable from arthritis following nonoperatively treated anterior shoulder instability.