Iranian Journal of Orthopedic Surgery

Abstract Abstract
Background: Venous thromboembolism (VTE) increases patient's morbidity and mortality after orthopedic surgeries, and as such, prophylaxis is a routine practice after total joint replacement. Although there are many effective and safe prophylactic agents, clinical results are suboptimal. The aim of this study was to compare clinical and ultrasonographic results for the use of low molecule weight heparin (LMWH) and Rivaroxaban in patients  undergoing total knee replacement.
Methods: In a prospective cross-sectional study 325 patients were enrolled in receiving   Enoxaparin or Rivaroxaban as thromboprophylaxis in their total knee replacement surgery. They had pre and post-operative doppler ultrasonography for diagnosis of thromboembolism. They were followed for a minimum of two years.  The status and occurrence of VTE was evaluated . Patients were compared in terms of gender, body mass index (BMI), smoking, diabetes mellitus (DM) and previous VTE history.
Results: The 325 eligible patients provided a sample of 130 (40%) male and 195 (60%) female. The average patient age (SD) was 63.2 (14.3).A  total of 40 (12.3%) patients (27 on  LMWH, and  13 on  Rivaroxaban),  had DVT at the lower extremity .15 (4.6 %) patients-11from  LMWH and 4 from Rivaroxaban group had pulmonary embolism (PE). 5 patients (1.5%) -4 on  LMWH, 1 on Rivaroxaban- had cerebrovascular thromboembolism. The incidence of thromboembolism was found to be similar in both prophylactic regimes. On the other hand, 2 patients (0.6%) had spontaneous retroperitoneal bleeding from LMWH group. The PE patients had  history of DVT.  DVT occurred in patients with risk factors of  obesity, diabetes or  smoking.
Conclusion: There was no difference between the use of rivaroxaban and enoxaparin for thromboembolic prophylaxis in total knee replacement in terms of occurrence of venous thrombosis and PE. Long-term thromboembolic prophylactic  is  preferred in cases with smoking, diabetes and obesity. Patients with previous venous thromboembolism are at a high risk for pulmonary and cerebrovascular embolism. Progressive hematocrit drop should alert the surgeon towards spontaneous retroperitoneal bleeding in the patients taking enoxaparin for thromboprophylaxis after total knee replacement surgery.