Investigation of the effects of Enoxaparin, Fondaparinux, and Rivaroxaban used in thromboembolism prophylaxis on fracture healing in rats.

BACKGROUND Today, there is a small number of studies on the effects of Enoxaparin and Fondaparinux used commonly in the prevention of venous thromboembolism on healing of fracture cases. AIM The aim of this study was to investigate clinically, radiologically and histopathologically, the effects of Enoxaparin, Fondaparinux and Rivaroxaban used in thromboembolism prophylaxis on fracture healing in a rat model of femur fracture. MATERIALS AND METHODS Thirty-two male Sprague Dawley rats were randomized into four groups (n=8): the control group (Group 1), the Enoxaparin group (Group 2), the Fondaparinux group (Group 3), and Rivaroxaban group (Group 4). Under general anesthesia, a standard closed fracture was created in the left femur of each rat using an osteotome. Group 1 was given saline solution (1 cc/day, sc), Group 2 Enoxaparin (100 anti Xa IU/kg/day, sc), Group 3 Fondaparinux (0.2 mg/kg/day, sc), and Group 4 Rivaroxaban (3 mg/kg/day, po) for 21 days. After all rats were sacrificed at the end of day 21, their left femurs were disarticulated at the level of the hip and knee. The bony union was radiologically, clinically, and histopathologically evaluated. RESULTS No differences were found between the groups in terms of clinical, radiological, and histopathological findings in fracture healing (p = 0.849, p = 0.731, and p = 0.395, respectively). CONCLUSIONS Enoxaparin, Fondaparinux and Rivaroxaban used in thromboembolism prophylaxis cause no significant changes in fracture healing with short term follow up. Thus, they can be safely used in cases of fractures.