Complications of perioperative warfarin therapy in total knee arthroplasty.

Patients presenting for knee replacement on warfarin for medical reasons often require higher levels of anticoagulation peri-operatively than primary thromboprophylaxis and may require bridging therapy with heparin. We performed a retrospective case control study on 149 consecutive primary knee arthroplasty patients to investigate whether anti-coagulation affected short-term outcomes. Specific outcome measures indicated significant increases in prolonged wound drainage (26.8% of cases vs 7.3% of controls, P<0.001); superficial infection (16.8% vs 3.3%, P<0.001); deep infection (6.0% vs 0%, P<0.001); return-to-theatre for washout (4.7% vs 0.7%, P=0.004); and revision (4.7% vs 0.3%, P=0.001). Management of patients on long-term warfarin therapy following TKR is particularly challenging, as the surgeon must balance risk of thromboembolism against post-operative complications on an individual patient basis in order to optimise outcomes.