The effect of enoxaparin in prevention of deep venous thrombosis in hip and knee surgery--a comparison with the dihydroergotamine-heparin combination.

A randomized study was carried out in order to compare the low-molecular heparin enoxaparin to heparin-dihydroergotamine (HDHE) combination, as prophylactic anti-thrombotic measure in patients undergoing hip replacement or knee replacement surgery or fractures of the femoral neck. A total of 165 patients both female and male were included in the study. The patients were randomized into two treatment groups. One group was treated with heparin-dihydroergotamine 0.5 mg + 5,000 IU twice a day and the other with enoxaparin 40 mg once daily. All patients were examined with Doppler ultrasound on day 3-5 and after the termination of medication which was the end of the study. Positive Doppler ultrasound findings were confirmed either by duplex Doppler or phlebography and clinical signs of pulmonary embolism were confirmed by isotope scintigraphy. The overall incidence of thromboembolic events was low (3%). One deep venous thrombosis (DVT) was seen in the enoxaparin group and two cases of pulmonary embolism in the heparin-dihydroergotamine group. Thus, the two regimens showed comparable efficacy and the overall safety was comparable. However, enoxaparin caused significantly less injection site haematoma. Correspondingly, the size of the injection site haematoma was significantly smaller in the enoxaparin group.