Antithrombotic Therapies and Their Associations With Periprosthetic Joint Infection Risk After Total Knee and Hip...

The impact of postoperative antithrombotic therapy (ATT) on complications such as periprosthetic joint infection (PJI) after total knee and hip arthroplasty (TKA and THA, respectively) remains understudied. We aimed to evaluate temporal trends in ATT use and the association between ATT type and PJI following primary TKA and THA.

We retrospectively reviewed 20,376 TKA and 16,074 THA patients receiving postoperative ATT between 2013 and 2025. Trends in ATT use were analyzed for all patients, but PJI incidence (2018 International Consensus Meeting definition) was assessed only in patients who had a minimum 90-day follow-up (14,663 TKA and 11,445 THA). Of these, 0.8 and 1.3% developed a PJI, respectively. Multivariate logistic regressions adjusted for age, sex, body mass index, smoking, and the Charlson Comorbidity Index were applied to assess the association between ATT and PJI.

From 2013 to 2025, aspirin monotherapy increased to account for the majority of prophylaxis (TKA: 2.0 to 59.4%; THA: 3.1 to 82.2%). In contrast, the use of low-molecular-weight heparin (LMWH) declined (TKA: 87.6 to 0.8%; THA: 86.7 to 2.3%), as did warfarin (TKA: 4.1 to 0.3%; THA: 3.4 to 0.9%) and rivaroxaban (TKA: 6.8 to 4.2%; THA: 8.9 to 2.8%). During the same period, apixaban use increased (TKA: 0 to 10.0%; THA: 0 to 12.7%). Aspirin monotherapy was associated with lower odds of PJI compared to nonaspirin regimens (adjusted odds ratio [OR] 0.60, 95% confidence interval [CI] 0.45 to 0.81, P = 0.001). Conversely, warfarin (OR: 8.01, 95% CI: 3.41 to 18.88, P < 0.001) and LMWH (OR: 1.89, 95% CI: 1.35 to 2.64, P < 0.001) were independently associated with increased PJI risk in THA.

Aspirin has become the dominant postoperative ATT agent. In THA, aspirin is associated with a significantly decreased risk of PJI compared to potent anticoagulants like warfarin and LMWH, while no such association was found in the TKA cohort. Surgeons should prioritize aspirin to minimize postoperative infection risk.