Thromboprophylaxis after total hip arthroplasty

Vein thromboembolism (VTE) is a potentially severe complication of elective total hip arthroplasty (THA) and the prosthetic surgery for femoral neck fracture. Anticoagulant prophylaxis for preventing venous VTE has become a well-established procedure in hip replacement surgery and several randomized controlled trials (RCT) demonstrated critical decrease in the prevalence of deep vein thrombosis since prophylaxis with low molecular weight heparin was introduced. Actually, the current reported prevalence of symptomatic VTE after THA is less than 1 %. Controversy still exists about the most cost-effective prophylactic regimen, when should prophylaxis be started, and how long should pharmacological prophylaxis last. Due to this uncertainty, different (and often contrasting) guidelines for the prophylaxis of VTE have been released by medical associations in the last five years. One relevant issue is to assess whether the recent introduction of oral factor Xa inhibitors (apixaban, rivaroxaban) and direct thrombin inhibitors (dabigatran) offer a convenient alternative to conventional anticoagulant drug regimens, including parenteral low-molecular-weight heparins and fondaparinux, in the surgical setting of hip THA. Current data suggests that new oral anticoagulants are superior to low molecular weight heparin in preventing deep vein thrombosis after THA, even though this better performance has not been univocally confirmed with respect to the decrease in the rate of postoperative pulmonary embolism and death. On this basis, the use of new anticoagulants can result in cost savings through improved efficacy in reducing deep vein thrombosis rates after THA and decreased drug administration and monitoring costs compared with traditional anticoagulants. Potential issues to be considered when using these oral anticoagulants include renal impairment, potential drug interactions, and major postoperative bleeding. According to the available guidelines, mechanical prophylaxis with intermittent pneumatic compression should be used in association with pharmacological prophylaxis.