Preoperative antithrombin III activities and lipoprotein concentrations as predictors of venous thrombosis in patients with fracture of neck of femur.

The presence or absence of venous thrombosis was determined by the technique of autologous 111indium-labelled platelets in 64 patients following reduction and fixation of fractures of the neck of femur. Venous thrombosis was found in 41 (64%) of these patients. Compared to the thrombosis-negative group, the thrombosis-positive group had a significantly lower mean serum antithrombin, and higher mean antithrombin consumption during clotting in the immediate preoperative period. No significant differences were seen between the two groups in plasma ATIII activities, fibrinogen, alpha-2-macroglobulin, serum lipoproteins or age. Significant correlations were seen between ATIII activities and lipoprotein fractions; these are discussed.