Safety and efficacy of a new thromboprophylaxis regiment for total knee and total hip replacement: a retrospective cohort study in 265 patients

BACKGROUND: Venous thromboembolism (VTE) remains a significant complication following knee and hip arthroplasty. National and international guidelines recommend pharmacological and mechanical thromboprophylaxis following surgery, unless contraindicated, to reduce the risk of VTE. This study aimed to explore the safety and efficacy profile of an adapted thromboprophylaxis regimen consisting of sequential enoxaparin and rivaroxaban for thromboprophylaxis following knee or hip arthroplasty at a London teaching hospital. METHODS: A total of 265 patients who received sequential enoxaparin and rivaroxaban and mechanical thromboprophylaxis following knee and hip arthroplasty were included in the study. Efficacy outcomes assessed for 90 days post-operatively included: pulmonary embolism, deep-vein thrombosis, other VTE, myocardial infarction, stroke and death secondary to thrombosis. Safety outcomes were assessed during and for two days after thromboprophylaxis course duration and consisted of major bleeding episodes, clinically-relevant non-major bleeding episodes, and total bleeding. RESULTS: There was 1 patient (0.4%) who experienced a stroke, and no other efficacy outcomes occurred. Major bleeding occurred in 2.3% (n = 6/265) of patients, whilst clinically-relevant non-major bleeding occurred in 3.4% (n = 9/265), with a total bleeding incidence of 16.2% (n = 43/265). No patients required a return to theatre. CONCLUSION: The regimen consisting of sequential enoxaparin and rivaroxaban is associated with a significant bleeding risk, although the risk of patients requiring a return to theatre is low. Further prospective trials are required to compare the safety and efficacy profiles of this regimen with established thromboprophylaxis regimens.