The frequency of venous thrombosis in cemented and non-cemented hip arthroplasty.

We randomised 250 patients undergoing unilateral, elective hip arthroplasty for osteoarthritis to receive either a cemented or a non-cemented Mallory Head prosthesis. Aspirin was used as prophylaxis against thromboembolism during the first half of the study and adjusted-dose warfarin during the second half. Postoperatively, all patients were asked to have bilateral venography and 80% agreed. All were evaluated clinically for pulmonary embolism. There was no difference in the frequency of deep-venous thrombosis between the two groups (50% cemented nu 47% non-cemented, p = 0.73; 95% CI of the difference -13.6% to 19.3%). Three of the 64 patients (5%) in whom venography had demonstrated isolated distal thrombi developed pulmonary emboli.