At Trondheim University Hospital, prophylaxis against thromboembolism after orthopaedic surgery was changed from dextran 70 to low molecular weight heparin in 1992. We wanted to assess whether the frequency of thromboembolic complications has fallen after this change of procedure and to search for any indication that prophylaxis should be prolonged from two to six weeks. Our register showed 97 cases (0.76%) with thromboembolism during the first 12 weeks after 12,711 operations during the dextran 70 period; 99 cases (0.54%) after 18,368 operations during the low molecular-weight heparin period (p
