Summary

Patients undergoing major orthopedic surgery are at an increasedrisk of thromboembolism even after the acute postoperativephase. Therefore, prolonged thromboprophylaxis iscurrently recommended and widely used.The length of hospitalstay after major orthopedic surgery is steadily decreasing andmost patients are transferred to specialized rehabilitationcenters in the early postoperative phase. Consequently, thromboprophylaxisis usually given during the rehabilitation period.Previously there have been no systematic studies of how manypatients with asymptomatic thrombosis are transferred to a rehabilitationcenter or how many patients develop deep veinthrombosis (DVT) during rehabilitation. In the present study,238 patients who had undergone major orthopedic surgerywere examined by compression ultrasonography on day 1 or 2and on day 20 of their rehabilitation phase in order to detect asymptomatic proximal DVT. Sonograms were read centrallywith blinding to the clinical course of the patients. All patientsreceived standard thromboprophylaxis during the acute postoperativephase. Prolonged thromboprophylaxis with enoxaparinwas given during the rehabilitation phase.The mean duration ofthromboprophylaxis was 36.8 days. At admission to the rehabilitationcenter,proximal DVT was identified in 16 patients (6.7%).New proximal DVT at discharge from the rehabilitation centerwas identified in 3.2% of patients following prolonged thromboprophylaxiswith enoxaparin. In conclusion, a considerable percentageof patients with asymptomatic proximal DVT are transferredto rehabilitation centers following major orthopedic surgery.Using prolonged thromboprophylaxis, new proximal DVTswill still develop during rehabilitation, but at a low rate.