In a prospective randomized study designed to compare the effectiveness of intraoperative electrical calf stimulation, perioperative low dosage heparin, and aspirin, either alone or in combination, as prophylactic measures for deep vein thrombosis following total hip replacement, the incidence of thrombosis, as diagnosed by the radioactive fibrinogen uptake test in the study groups was: Control – 9 out of 20 (45%); Calf Stimulation – 9 out of 22 (41%); Aspirin – 9 out of 20 (45%); Heparin – 7 out of 21 (33%); Aspirin plus Calf Stimulation – 10 out of 20 (50%); Heparin plus Calf Stimulation – 0 out of 25.Following this study only 2 patients developed thrombosis during the period of heparin administration out of a further 104 consecutive patients given low dosage heparin and calf stimulation. Of these patients, thrombosis occurred within 48 hours of cessation of heparin in 11 out of 52 (23%) given heparin until the tenth postoperative day, and in 7 out of 75 (9% ) given heparin until the 14th postoperative day.Data will be presented to support the following conclusions : 1. The incidence of thrombosis is (i) high (about 50%), (ii) over 50% of thromboses occur either during or soon after operation, (iii) no more frequent in either the operated or non-operated legs. 2. Clinical Diagnosis of thrombosis is grossly inadequate. 3. Prophylaxis is: (i) ineffective with aspirin and calf stimulation, either alone or in combination, or with low dosage heparin alone, (ii) significant with a combination of intraoperative electrical calf stimulation and perioperative low dosage heparin in that the incidence is markedly reduced and the onset delayed the longer the heparin is administered. 4. Low dosage heparin or aspirin does not increase the risk of haemorrhage.
A prospective randomized study on the use of nadroparin calcium in the prophylaxis of thromboembolism in Korean patients undergoing elective total hip replacement