Risk of clinical pulmonary embolism after joint surgery in patients receiving low-molecular-weight heparin prophylaxis in hospital: a 10-year prospective register of 3,954 patients.

We studied the incidence of nonfatal, radiologically-confirmed, clinical pulmonary embolism (PE) after major joint surgery during 10 years of observation. The findings are based on a prospective register of all patients undergoing total hip replacement (THR), total knee replacement (TKR), or nailed hip fracture (NHF) in a Scandinavian hospital between 1989 and 1998. All patients received thromboprophylaxis with low-molecular-weight heparin, continued until discharge. Patients with suspected PE underwent ventilation/perfusion scintigraphy and/or spiral CT. Patients with concomitant clinical signs of deep vein thrombosis (DVT) were also subjected to imaging diagnostics. 3,954 patients underwent THR, TKR, or NHF; 122 of them were readmitted on clinical suspicion of PE, and 50 cases were confirmed. Of patients with confirmed PE, 6/50 had DVT. The average time to readmission was 35 (5-94) days after THR, 24 (1-173) days after NHF, and 9 (2-17) days after TKR. Following major hip surgery, the incidence of PE remained high for at least 2-3 months (less following TKR) in those given thromboprophylaxis for about 10 days. The differences in PE incidence and the time when it developed in NHF versus THR and TKR patients suggest that these patients should be considered separately when determining the optimal thromboprophylactic regimen.