Background: Radiographic changes in the glenohumeral joint often occur after rotator cuff repair; however, the details of the progression and underlying causes remain unknown. Purpose: To retrospectively evaluate the timing and frequency of radiographic changes after arthroscopic rotator cuff repair and to clarify the predictive factors that affect the onset of such changes using multivariate analysis. Study Design: Case-control study; Level of evidence, 3. Methods: We retrospectively reviewed 100 patients with 5 years of follow-up after arthroscopic rotator cuff repair and evaluated the postoperative shift in radiographic findings on plain radiographs every year during follow-up. Factors related to osteoarthritis, acromial spur re-formation, and greater tuberosity resorption at 5 years after surgery were evaluated using logistic regression analyses. Explanatory variables included preoperative factors, intraoperative factors, and postoperative retear. Baseline variables significant in the univariate analyses were included in the multivariate models. Results: Of the 100 patients, 12 developed osteoarthritis, 26 developed acromial spur formation, and 16 developed greater tuberosity resorption at 5 years after surgery. The incidence and grade of osteoarthritis and acromial spur gradually increased over time postoperatively. On the other hand, greater tuberosity resorption developed within 2 years after surgery but did not progress later. Multivariate analysis showed that a larger anteroposterior tear size (odds ratio [OR], 1.09; 95% CI, 1.01-1.17; P =.037) was a risk factor for postoperative osteoarthritis. Early retear (OR, 10.26; 95% CI, 1.03-102.40; P =.047) was a risk factor for acromial spur re-formation. Roughness of the greater tuberosity (OR, 9.07; 95% CI, 1.13-72.82; P =.038) and larger number of suture anchors (OR, 3.34; 95% CI, 1.66-6.74; P =.001) were risk factors for greater tuberosity resorption. Conclusion: Our study showed that radiographic changes occurred in 40% of patients within 5 years after arthroscopic rotator cuff repair. While the osteoarthritic changes and acromial spur re-formation gradually progressed postoperatively, the greater tuberosity resorption stopped within 2 years after surgery. Tear size, morphology of the greater tuberosity, and the number of suture anchors can affect radiographic changes. Furthermore, this study suggested that acromial spur re-formation may be an indicator of early retears.
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