Outcomes of Total Knee Arthroplasty in Patients Receiving Chronic Antithrombotic Therapy: A Systematic Review.

BACKGROUND: With population aging and increasing cardiovascular comorbidity, more patients undergoing total knee arthroplasty (TKA) require chronic antithrombotic therapy. The impact of long-term anticoagulant or antiplatelet use on perioperative and longer-term outcomes after TKA remains unclear. This systematic review summarizes postoperative outcomes in patients receiving chronic antithrombotic therapy, examines differences by antithrombotic class, and compares outcomes with non-anticoagulated controls.

METHODS: A systematic literature search was conducted through October 2025. There were 17 retrospective studies, including 104,182 patients receiving chronic antithrombotic therapy and 261,139 controls, that were analyzed. Studies reporting outcomes of primary TKA in patients receiving long-term antithrombotic therapy were included. Extracted outcomes comprised perioperative parameters, medical complications, thromboembolic events, and longer-term outcomes. Antithrombotic regimens were categorized as antiplatelet therapy, warfarin, Direct oral anticoagulants or mixed regimen (outcomes were not reported separately by anticoagulant class in this group), and findings were synthesized descriptively.

RESULTS: Warfarin use was associated with greater blood loss, higher transfusion rates, and longer hospitalization, whereas antiplatelet therapy showed no consistent adverse perioperative effects. Direct oral anticoagulant therapy was related to lower rates of periprosthetic joint infection and wound dehiscence. Reporting of thromboembolic, infectious, wound, and revision outcomes was heterogeneous.

CONCLUSION: Warfarin use in TKA, compared with antiplatelet and direct oral anticoagulant therapy, is associated with greater blood loss, longer hospitalization, and higher risk of wound complications, myocardial infarction and pulmonary embolism, while other outcomes show no difference or remain inconclusive. Despite this, TKA is feasible under chronic antithrombotic therapy with proper perioperative management, though warfarin patients require closer monitoring and further research is needed.