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

Abstract

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 (≥45 years) who underwent major knee surgery from 1998 to 2007 and collected the medical records within 3 months after the discharge. Logistic regression analysis was used to determine the risk factors of symptomatic VTE after the surgery.

Results: We identified 113 844 patients (mean age, 69.0 ± 7.7 years; female, 75.2%) receiving major knee arthroplasties. The mean length of stay was 9.1 ± 3.3 days. 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 7 days, with 85.4% occurring within 2 weeks 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 2 weeks after the surgery. Universal thromboprophylaxis for knee arthroplasties may not be necessary in Taiwan, but it should be considered in some high-risk populations.