Aspirin Versus Direct Oral Anticoagulants for Venous Thromboembolism Prophylaxis After Total Knee Arthroplasty: A 10-year Retrospective Cohort Study

Background: Although venous thromboembolism (VTE) prophylaxis has been widely studied, comparative data evaluating aspirin versus direct oral anticoagulants (DOACs) following primary total knee arthroplasty (TKA) remain limited. The study evaluated deep vein thrombosis (DVT) and pulmonary embolism (PE) incidence in patients prescribed aspirin or DOACs. Materials and Methods: We retrospectively examined patients undergoing primary TKA at a single academic medical center over a 10-year period. There were 2,232 patients in the aspirin group and 1,638 in the DOAC group. Primary outcome measures include incidence of DVT and PE. A logistic regression model adjusted for differences across groups in relation to the primary outcome measures. Results: The incidence of PEs (0.4% vs 0.6%, P = .486) and DVTs (1.3% vs 1.4%, P = .780) at 90 days were similar between the aspirin and DOAC groups, respectively. After adjusting for significant covariates in the logistic regression model, there remained no differences in the rate of PE and DVT between groups. The incidence of re-operation (0.4% vs 1.0%) was statistically different ( P = .009) between the aspirin and DOAC groups at 90 days, respectively. Conclusion: Our study revealed no significant differences in the incidence of PE and DVT among patients receiving either DOACs or aspirin following primary TKA. While the rate of reoperation at 90 days was higher in the DOAC group, no differences were observed at 1 year. This study adds to the growing body of evidence demonstrating the safety and efficacy of aspirin for VTE prophylaxis in TKA.