In a prospective study fo the incidence of deep-vein thrombosis in
thirty patients undergoing total knee replacement, all patients had
clinical examinations and 125I fibrinogen scanning, while those suspected
of having deep venous thrombosis also had confirmatory venography. Sixteen
(53 per cent) of the thirty patients had thromboembolic disease; nine had
thrombi only in the limb operated on; four had bilateral deep venous
thrombi; and three had pulmonary embolism. In nine patients who took
aspirin regularly the incidence of thromboembolism was 11 per cent, while
in the eight who did not take aspirin or any other antiplatelet drug the
incidence was 88 per cent, a difference which was highly significant (p =
0.003).