The John Charnley Award. Natural history of thromboembolic disease after total hip arthroplasty.

In 1079 consecutive patients undergoing total hip arthroplasty between 1984 and 1992, complications of thromboembolic disease and related anticoagulation were reviewed for 6 months after hospital discharge, including cost data. Of 347 patients having venograms, 78 (22.5%) had positive results and 269 (77.5%) had negative results for deep venous thrombosis. In patients with negative venograms, 3 (1.1%) were readmitted with 2 symptomatic deep venous thromboses and nonfatal pulmonary embolism. There were no readmissions among the 55 patients who had venographically evident deep venous thrombosis diagnosed and treated with outpatient warfarin. Overall, 3 of 324 (0.9%) patients with true positive or negative venograms were readmitted for complications of thromboembolic disease. In contrast, 12 of 732 (1.6%) patients not receiving contrast venography were readmitted, including 9 (1.2%) deep venous thromboses and 3 (0.4%) nonfatal pulmonary embolisms. Four of 23 patients (17.4%) with untreated calf deep venous thrombosis suffered 2 nonfatal pulmonary embolisms resulting in readmission and 2 fatal pulmonary embolisms outside the hospital. Untreated calf deep venous thrombosis after total hip arthroplasty represents a significant threat of extension to more proximal veins and distant embolization. Routine thromboembolic disease prophylaxis combined with screening contrast venography and selective therapeutic anticoagulation is effective in preventing late thromboembolic disease complications and, compared with a strategy of extended prophylaxis for all, is cost effective management by reducing exposure of the elderly population to outpatient anticoagulant therapy.