Risk factors for failing to achieve improvement after anatomic total shoulder arthroplasty for glenohumeral osteoarthritis

Background: Although anatomic total shoulder arthroplasty (TSA) successfully improves pain and function, not all patients improve clinically. This study was conducted to determine patient-related factors for failure to achieve improvement after primary TSA for osteoarthritis at 2 years postoperatively. Methods: This prospective study reviewed an institutional shoulder registry for consecutive patients who underwent primary TSA for osteoarthritis from 2007 to 2013 with baseline and 2-year postoperative American Shoulder and Elbow Surgeons (ASES) Standardized Shoulder Assessment Form scores. A failed outcome was defined as (1) a failure to reach the ASES minimal clinically important difference of 16.1 points or (2) revision surgery within 2 years of the index procedure, or both. Univariate and multivariable analyses of clinical and demographic patient factors were performed using logistic regression. Results: Of 459 arthroplasties that met inclusion criteria, 411 were deemed successful by the aforementioned criteria, and 48 (10.5%) failed to achieve a desirable outcome. Clinical risk factors associated with failure included previous surgery to the shoulder (P =.047), presence of a torn rotator cuff (P =.025), and presence of diabetes (P =.036), after adjusting for age, sex, race, and body mass index. A higher preoperative ASES score at baseline was associated with failure (P <.001). Conclusion: Previous shoulder surgery, a rotator cuff tear requiring repair during TSA, presence of diabetes, surgery on the nondominant arm, and a higher baseline ASES score were associated with a higher risk of failing to achieve improvement after anatomic TSA.