Inability of serial fibrin monomer measurements to predict or exclude deepvenous thrombosis in asymptomatic patients undergoing total knee arthroplasty

Fibrin monomer (FM) is a highly sensitive marker of venous thromboembolism and can be used to rule out deep venous thrombosis (DVT) and/or pulmonary e mbolism in symptomatic outpatients. The aim of the study was to investigate the usefulness of serial fibrin monomer determinations to predict or rule out DVT after total knee arthroplasty in asymptomatic patients. One hundred and thirty consecutive patients underwent total knee replacement. Blood sa mples were obtained in 104 of them the day before, at days 1, 3, 6 after su rgery and at the day of phlebography. Phlebography was performed in all the se patients between days 8 and 12 after surgery. There were 44 DVT (44/104, 42%). As compared with the patients without DVT, FM mean levels were 2 and 1.5 times higher in the DVT group at day 3 (P < 0.001) and day 6 (P < 0.01 ), respectively. However, no useful cut-off values for DVT prediction or ex clusion could be determined due to the scattering of the values. Therefore, despite differences between patients with Or without DVT, serial FM determ inations are of no value for predicting or ruling out DVT in individual pat ients undergoing total knee arthroplasty. Blood Coagul Fibrinolysis 11:305- 308 (C) 2000 Lippincott Williams & Wilkins.