Analysis of 90-Day Readmissions After Total Shoulder Arthroplasty

Background: The number of total shoulder arthroplasty (TSA) procedures performed annually is increasing as a result of an aging population and an increased access to subspecialty-trained upper extremity arthroplasty surgeons. An up-to-date analysis of the incidence of, risk factors for, and reasons for 90-day readmissions in primary anatomic TSA has yet to be performed. Purpose: To characterize 90-day readmissions on a national level. An understanding of these data will help to predict resource utilization and expenses in shoulder arthroplasty. Study Design: Case-control study; Level of evidence, 3. Methods: All adult patients undergoing elective primary TSA in 2014 who were included in the National Readmission Database were included in the analysis. Two cohorts were created according to 90-day readmission status. Multivariable analysis was then performed to determine predictors of 90-day readmissions. Reasons for 30-, 60-, and 90-day readmissions were identified, and total hospital resource utilization was calculated. Results: An estimated 26,023 patients were identified. The 30-, 60-, and 90-day rates of readmissions were 0.6%, 1.2%, and 1.7%, respectively. There was no difference in comorbidity burden between the cohorts. Medicare payer status (odds ratio [OR], 1.63; 95% CI, 1.00-2.65; P = .05), transfer to a skilled nurse facility (OR, 1.50; 95% CI, 1.05-2.14; P = .02), and chronic obstructive pulmonary disease (OR, 1.32; 95% CI, 1.04-1.66; P = .02) were identified as predictors of 90-day readmission. Female sex decreased odds of 90-day readmission (OR, 0.72; 95% CI, 0.59-0.87; P = .001). Ninety-day readmissions were associated with significant cost increases ( P < .001). The most common identifiable reason for related readmissions was a hardware-related complication at all time points. Conclusion: While uncommon, 90-day readmissions after primary TSA are associated with significant patient morbidity and ultimately substantial hospital costs. Truncating readmission analysis at a 30-day period will miss most arthroplasty-related hospital readmissions.