McKenna R, Galante J, Bachmann F, Wallace DL, Kaushal PS, Meredith P.
Prevention of venous thromboembolism after total knee replacement by high-dose
aspirin or intermittent calf and thigh compression.
Br Med J 1980 Feb 23;280(6213):514-7

A prospective study of patients undergoing total knee replacement was carried out
by using a combination of 125I-fibrinogen scanning and phlebography, and showed a
high incidence of venous thromboembolic disease (TE). Ventilation-perfusion lung
scanning was performed to detect pulmonary emboli in most patients. High doses of
aspirin and an intermittent low-pressure pneumatic compression device (IPCD) were
effective, even in women, in preventing TE. Low doses of aspirin and placebo were
equally ineffective in preventing TE. Lung-scan abnormalities compatible with
pulmonary emboli were found in six out of 10 patients with isolated calf-vein
thrombi. Conventional tests of platelet function did not predict the development
of TE. No significant differences were found between the patients receiving low
and high doses of aspirin with respect to the mean template bleeding time or
platelet aggregation in response to adenosine diphosphate, collagen, and
epinephrine, although these variables were significantly abnormal in the two
groups receiving aspirin compared with those treated with placebo and the IPCD.
Thus high doses of aspirin and a new low-pressure IPCD were effective in
preventing venous TE in patients (predominantly women) undergoing total knee
replacement.