Extended oral antibiotic prophylaxis does not reduce periprosthetic joint infection after primary outpatient total shoulder arthroplasty: A matched cohort analysis

Background Over the last decade, total shoulder arthroplasty (TSA) has increasingly transitioned to the outpatient setting, where postoperative care pathways inherently limit the ability to deliver a full 24 hour course of intravenous antibiotic prophylaxis. Despite guideline recommendations, extended oral antibiotic prophylaxis is variably used after outpatient TSA, with limited evidence supporting this practice. Methods A retrospective cohort study using the TriNetX database identified patients undergoing primary outpatient TSA between 2015 and 2025. Patients were stratified by receipt of extended oral antibiotic prophylaxis. Propensity score matching yielded two cohorts of 2647 patients each. Outcomes included periprosthetic joint infection (PJI), surgical site infection (SSI), all-cause revision, wound disruption, and emergency department utilization at 90 days and 1 year. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated. Results At 90 days, there were no significant differences in PJI (0.9% vs 0.5%; RR 1.20, 95% CI 0.96–3.84) or SSI (0.8% vs 0.5%; RR 1.67, 95% CI 0.82–3.40). At 1 year, PJI (1.6% vs 1.2%; RR 1.34, 95% CI 0.85–2.12) and SSI (1.1% vs 0.8%; RR 1.14, 95% CI 0.79–2.42) rates remained comparable between groups. Discussion Extended oral antibiotic prophylaxis did not reduce infection-related outcomes following primary outpatient TSA. Level of evidence III, Retrospective cohort study.