Venous thromboembolism remains the most common cause of
hospital readmission and death after total joint
arthroplasty. The 2008 American College of Chest Physicians (ACCP) guidelines, based on prospective randomized clinical trials with a venography endpoint, endorse the use of
low-molecular-weight heparin,
fondaparinux, or adjusted dose
warfarin (target international normalized ratio, 2.5; range, 2-3) for up to 35 days after
total hip arthroplasty (THA) and
total knee arthroplasty (TKA). In the past, the ACCP has recommended against the use of
aspirin, graduated
compression stockings, or venous compression devices as the sole means of prophylaxis, but in 2008 they first recommended the "optimal use of mechanical thromboprophylaxis with venous foot pumps or
intermittent pneumatic compression devices" in patients undergoing total joint
arthroplasty who "have a high risk of
bleeding." When the high risk subsides, pharmacologic thromboprophylaxis is substituted for, or added to, mechanical methods. Fractionated heparins and pentasaccharide are the most effective agents in reducing venographic
deep venous thrombosis (DVT) after total joint
arthroplasty with residual clot rates <5% after THA and 20% after TKA, but major or clinically meaningful
bleeding occurs in 3% to 5% of patients. Newer Xa and
thrombin inhibitors enjoy greater efficacy with equal or higher
bleeding rates. Low-intensity
warfarin (target international normalized ratio, 2.0) combines safety (
bleeding rates <1%) with efficacy (readmission for clinical DVT or
pulmonary embolism 0.2%) after total joint
arthroplasty.
Warfarin represents a therapeutic compromise by preventing clinical events in exchange for a lower
bleeding rate; genetic testing will likely simplify
warfarin use and reduce outlier responders.