Does anticoagulation do more harm than good?: A comparison of patients treated without prophylaxis and patients treated with low-dose warfarin after total knee arthroplasty.

A cohort of 785 patients treated without any form of thromboprophylaxis was compared with an identical group of 957 patients treated with 6 weeks of low-dose warfarin. All complications seen within 90 days of surgery were recorded. The control group had a total complication rate of 2.2%, with a death rate from thromboembolic disease of 0.0% and a total death rate of 0.2%. The warfarin group had a total complication rate of 4.7%, with a death rate from thromboembolic disease of 0.0% and a total death rate of 0.1%. Both deaths in the control group were from cardiac disease, while the death in the warfarin group was due to a massive gastrointestinal bleeding. The warfarin group had twice the infection rate of the control group.