Duration of thrombosis prophylaxis in orthopaedic surgery

Background: We have given seven to 14 days thrombosis prophylaxis after orthopaedic surgery. Recently, six weeks prophylaxis has been recommended. We wished to evaluate the implications of prolonging prophylaxis. Methods: We made a very thorough search of the hospital register of diagnoses and the registers of the departments of radiology and nuclear medicine and determined the number of detected thromboembolic complications during a five and a half-year period. Results: We identified 91 cases (0.50%) with thromboembolism during the first six weeks after 18.368 orthopaedic operations: 1.4% after 836 total hip arthroplasties and 1.0% after 1.845 hip fractures. In these two groups 19 thromboembolic complications were registered after the second postoperative week. If it had been possible to prevent all of them by prolonging prophylaxis to six weeks, each avoided