Hemarthrosis associated with sodium warfarin therapy.

Three patients with hemarthrosis of the knee joint complicating sodium warfarin oral anticoagulation therapy are described. In all 3 the prothrombin time was at least 2.4 times the control value at the time of hemarthrosis. After initial bleeding was controlled, 2 patients had recurrences at times when their prothrombin times were again more than 2.5 times greater than those of the normal control subject. Joint symptoms persisted in all patients until the warfarin dose was substantially decreased or discontinued. Underlying joint disease was present in 1 individual and may have predisposed him to the occurrence of hemarthrosis. No long-term joint damage was recognized as resulting from the hemarthrosis at followup 1 to 2 years later. The authors conclude that hemathrosis associated with oral anticoagulant therapy occurs when the prothrombin time is excessively prolonged any may remain symptomatic until anticoagulation is reduced or discontinued. Management includes careful diagnostic aspiration, despite the prolonged prothrombin time, and discontinuation of anticoagulation.