Serious adverse events, readmission, and mortality after shoulder replacement due to fracture, osteoarthritis, and other indications: a population-based comparison with the general population

Background and purpose — Patients treated with shoulder arthroplasty may risk serious adverse events (SAEs), readmission, and death; however, the literature is inconsistent. Therefore, we aimed to compare the incidence rates of SAEs, readmissions, and mortality at 30 and 90 days following shoulder replacement with those of a matched cohort. Methods — Danish databases were used to include patients treated with a primary shoulder replacement due to fracture, osteoarthritis, cuff tear arthropathy, and other (2006–2021). The shoulder patients were compared (1:10) to a matched cohort from the general population. Incidence rates (IR) and incidence rate ratios (IRR) were calculated and adjusted for age, sex, and comorbidity. Results — The 30-day IR of SAEs was 73.5 for shoulder patients and 14.8 for the matched cohort. The IRR of SAEs was higher for all patient groups compared with the matched cohort and varied between indications for surgery (IRR 3.1– 5.9) and remained higher at 90 days (IRR 1.6–3.5). The IR of readmission was 234 per 100,000 person-days at 30 days. The 30-day IR of mortality was 20.2 per 100,000 persondays for shoulder patients and 9.4 per 100,000 person-days for the matched cohort. Compared with the matched cohort the 30-day IRR of mortality was 2.0, with fracture patients having the highest risk of mortality (IRR of 3.5). Conclusion — At 30 and 90 days after surgery, shoulder patients, regardless of surgical indications, had higher rates of SAEs than the matched cohort. The mortality rate was higher for shoulder patients and highest for fracture patients. This information should be included in the shared decisionmaking process before undergoing shoulder replacement.