METHODS: Using medical databases, we identified all patients who underwent primary
total hip replacement and received pharmacological thromboprophylaxis in Denmark from 1995 to 2006. The outcome measure was hospitalization with
venous thromboembolism within ninety days of surgery. We considered age, sex, indication for primary
total hip replacement, calendar year of surgery, and comorbidity history as potential risk factors.
RESULTS: The overall rate of hospitalization for
venous thromboembolism within ninety days following a primary
total hip replacement was 1.02% (686 hospitalizations after 67,469 procedures) at a median of twenty-two days. The incidence of symptomatic
deep venous thrombosis and of nonfatal
pulmonary embolism was 0.7% (499 of 67,469) and 0.3% (205 of 67,469), respectively. The incidence of death due to
venous thromboembolism or from all causes was 0.05% (thirty-eight patients) and 1.0% (678 patients), respectively. Patients with
rheumatoid arthritis had a reduced relative risk for
venous thromboembolism compared with patients with primary
osteoarthritis (adjusted relative risk = 0.47; 95% confidence interval, 0.25 to 0.90). Patients with a high score on the Charlson comorbidity index had an increased relative risk for
venous thromboembolism compared with patients with a low score (adjusted relative risk = 1.45; 95% confidence interval, 1.02 to 2.05). Patients with a history of
cardiovascular disease (relative risk = 1.40; 95% confidence interval, 1.15 to 1.70) or prior
venous thromboembolism (relative risk = 8.09; 95% confidence interval, 6.07 to 10.77) had an increased risk for
venous thromboembolism compared with patients without that history.
CONCLUSIONS: