Thromboprophylaxis after Knee Arthroscopy and Lower-Leg Casting

Area of Science:

• Orthopedic Surgery
• Vascular Medicine
• Clinical Trials

Background:

• The efficacy of thromboprophylaxis (preventive anticoagulant therapy) for venous thromboembolism (VTE) after knee arthroscopy or lower leg casting is debated.
• This study aimed to compare VTE incidence in patients receiving anticoagulant therapy versus those not receiving it after these procedures.

Purpose of the Study:

• To evaluate the effectiveness of low-molecular-weight heparin (LMWH) in preventing symptomatic venous thromboembolism (VTE) after knee arthroscopy and lower leg casting.
• To assess the incidence of major bleeding associated with LMWH prophylaxis in these patient groups.

Main Methods:

• Two parallel, pragmatic, multicenter, randomized, controlled, open-label trials (POT-KAST for knee arthroscopy, POT-CAST for lower leg casting) were conducted.
• Patients received either prophylactic LMWH or no anticoagulant therapy.
• Primary outcomes included cumulative incidences of symptomatic VTE and major bleeding within 3 months post-procedure.

Main Results:

• In POT-KAST, VTE occurred in 0.7% of the LMWH group vs. 0.4% of the control group (RR 1.6; 95% CI 0.4-6.8).
• In POT-CAST, VTE occurred in 1.4% of the LMWH group vs. 1.8% of the control group (RR 0.8; 95% CI 0.3-1.7).
• Major bleeding rates were low and similar between groups in both trials; infection was the most common adverse event.

Conclusions:

• Prophylaxis with LMWH for 8 days post-knee arthroscopy or during immobilization for lower leg casting was not effective in preventing symptomatic VTE.
• The findings suggest that routine thromboprophylaxis with LMWH may not be beneficial for patients undergoing these specific orthopedic procedures.