Venous thromboembolic disease after total hip arthroplasty

Venous thromboembolic (VTE) events are common complications following total hip arthroplasty (THA). In order to prevent these events there is a common agreement among orthopedic surgeons on the necessity to use some kind of thromboprophylaxis in hospital after THA. However, barriers exist to prescribing prophylaxis after discharge from hospital because of concerns about adherence, bleeding, adverse events and outpatient monitoring. This skepticism is based on the limitations of the existing prophylactic methods. New management approaches have, therefore, been in demand for many years in order to give surgeons and patients greater incentives to comply with prophylaxis guidelines and to provide adequate prophylaxis following discharge, where needed. Two new orally administered drugs with different attack points in the coagulation system have recently been launched on the markets in Europe and Canada: dabigatran etexilate, a direct thrombin inhibitor and rivaroxaban, a direct Factor Xa inhibitor. Both can be administered orally at a fixed dose, have a rapid onset of action, are well tolerated and need no regular monitoring. Both drugs have undergone clinical testing in THA patients in a number of well-designed phase III, randomized, controlled trials with enoxaparin (a low molecular weight heparin) in the comparator arm. The result of these trials has been that relative to enoxaparin dabigatran etexilate has demonstrated a non-inferior effectiveness and an equal safety and that rivaroxaban has demonstrated superiority without significantly increasing the rate of major bleeding in the prevention of VTE.