D-dimer and thrombin-antithrombin III complex levels uncorrelated with phlebographic findings in 11 total knee replacement patients.

D-dimer and thrombin-antithrombin III complex (TAT) were assayed in 11 patients at various times pre- and post-operatively in order to determine the possible value of these parameters in screening for thromboembolic complications. Phlebography revealed distal thrombosis in 6 of the 11 patients. The D-dimer level, already elevated before surgery, increased at day 1 and remained high at days 5 and 10. Two methods were used for the assays and showed strongly correlated results. The TAT level increased at day 1 and then progressively returned toward basal values. No difference was observed at any time between patients with or without thrombosis. The results in surgical patients undergoing knee replacement suggest that neither D-dimer nor TAT assays are valid screening procedures for post-operative DVT. Nevertheless, in view of the small number of patient studied, further work is required to confirm these results.