Comparative efficacy of aspirin versus direct oral anticoagulants for venous thromboembolism prophylaxis following primary total hip arthroplasty or total knee arthroplasty: A systematic review and meta-analysis of randomised controlled trials.

Introduction: Venous thromboembolisms (VTEs), including deep vein thrombosis (DVT) and pulmonary embolisms (PE), are common after total knee (TKA) and hip arthroplasty (THA). Recent studies suggest that aspirin effectively prevents VTE following major orthopaedic surgery. This meta-analysis compares randomised controlled trials (RCTs) evaluating aspirin versus direct oral anticoagulants (DOACs) for VTE prevention after primary THA and TKA. Methods: We included RCTs from 2017 to 2023 that looked at aspirin versus DOACs for VTE prophylaxis in primary THA and TKA. A search strategy was conducted which used Boolean operators and MESH terms. Primary outcomes included VTE rates, symptomatic, asymptomatic DVT and PE. Secondary outcomes were mortality and bleeding complications. Statistical analysis was performed using REVMAN software. An odds ratio with a 95% confidence interval was generated for the pooled studies. Heterogeneity was assessed using the Results: Seven RCTs with 3967 patients were included for analysis. Rivaroxaban 10 mg OD was compared to varying doses of aspirin (81-300 mg). There were no significant differences between the groups in the incidence of VTE (OR: 1.21, 95% CI: 0.72-2.01), PE (OR: 1.01, 95% CI: 0.39-2.61), asymptomatic DVT (OR: 1.39, 95% CI: 0.64-3.00), suspected DVT (OR: 1.13, 95% CI: 0.49-2.61) and major bleeding (OR: 0.84, 95% CI: 0.55-1.27). Discussion: Aspirin is as effective as rivaroxaban for primary thromboprophylaxis post-THA and TKA, without increased incidence of complications. Further research is needed to determine the optimal dosing regimen of aspirin and its long-term efficacy in preventing VTE. Level of Evidence: Level I.