Pre-operative antiplatelet therapy is associated with increased risk of periprosthetic joint infection following total shoulder arthroplasty.

Background: Antiplatelet therapy is widely prescribed for the prevention and management of cardiovascular disease and for mitigation of thromboembolic risk. However, its impact on post-operative periprosthetic joint infection (PJI) following total shoulder arthroplasty (TSA) remains poorly defined. Methods: A retrospective cohort study was conducted using the TriNetX US Research Network. Propensity score matching was performed to balance demographics, body mass index, and Charlson Comorbidity Index variables. The primary outcome was the incidence of PJI at 90 days, 6 months, and 1 year. Secondary outcomes included post-operative medical and surgical complications. Comparative risk was quantified using risk ratios with 95% confidence intervals. Subgroup analyses evaluated obese, frail, as well as antiplatelet subclass groups. Results: Following 1:1 propensity score matching, 51,020 patients remained in each cohort. Pre-operative antiplatelet use was associated with a significantly higher risk of PJI at 90 days (risk ratio [RR], 2.00), 6 months (RR, 1.87), and 1 year (RR, 1.80) (all Conclusion: Pre-operative antiplatelet therapy in patients undergoing TSA was associated with an increased risk of PJI and higher rates of post-operative medical and surgical complications. These findings suggest that antiplatelet exposure may represent an important modifiable risk factor for infection following TSA and should be carefully considered during perioperative risk stratification and surgical optimization.