Universal pharmacological thromboprophylaxis for total knee arthroplasty may not be necessary in low-risk populations: A nationwide study in Taiwan

Summary. Background:Thromboprophylaxis should be universally administered in major orthopedic surgery. However, epidemiology of venous thromboembolism (VTE) following major knee surgery in Asia is scarce. Objective:To describe the use of thromboprophylaxis and calculate the incidence and risk factors of symptomatic VTE following major knee surgery in Taiwan. Methods:We used Taiwan's National Health Insurance Research Database to retrospectively identify patients (≧45years) who underwent major knee surgery from 1998 to 2007 and collected the medical records within 3months after the discharge. Logistic regression analysis was used to determine the risk factors of symptomatic VTE after the surgery. Results:We identified 113844 patients (mean age, 69.0±7.7years; female, 75.2%) receiving major knee arthroplasties. The mean length of stay was 9.1±3.3days. The overall pharmacological thromboprophylaxis rate was 2.2%. The 3-month cumulative incidence of procedure-related symptomatic VTE was 0.46% (95% CI, 0.42-0.50%). The median time to the first post-operation VTE was 7days, with 85.4% occurring within 2weeks after the discharge. Logistic regression analysis showed that previous VTE, malignancy, heart failure and neurologic disorder with extremity paralysis or pararesis were independent risk factors (P<0.05) for symptomatic VTE following major knee arthroplasties. Conclusions:The thromboprophylaxis rate is low, which may be due to the very low incidence of symptomatic VTE after the surgery in Taiwan. Most symptomatic VTE occurred within 2weeks after the surgery. Universal thromboprophylaxis for knee arthroplasties may not be necessary in Taiwan, but it should be considered in some high-risk populations.