Preparation of a femoral fracture model combined with spinal cord injury in Sprague-Dawley rats / 中国组织工程研究

ABSTRACT

BACKGROUND:In the animal model of spinal cord injury associated with fractures, the trauma is severe and postoperative survival rate is low. The improved Al en method and open femoral osteotomy method for making animal model has many advantages, such as simple operation, no need of special equipment, quick establishment, shortened operation time and reduced intraoperative bleeding, so they are suitable for preparing a femoral fracture model combined with spinal cord injury. OBJECTIVE:To design an animal model of femoral fracture combined with spinal cord injury, which can maintain long time survival, meet clinical features, and is simple and easy. METHODS:Forty-eight male Sprague-Dawley rats were randomly divided into simple femoral fracture group and femoral fracture merging spinal cord injury group. Femoral fracture model was caused by opening osteotomy to cause transverse fracture and implantation of internal fixator in femur. According to the improved Al en method, a self-made blow device was applied to cause acute T 10 segment contusion injury of spinal cord in rats. Thus the femoral fracture model merging spinal cord injury was successful y established. The rats in two groups were grossly observed at different time points after the modeling, and the fracture healing at 4 weeks was detected. RESULTS AND CONCLUSION:Al the animal models of femoral fracture with spinal cord injury survived, which exhibited the loss of sensory and motor function of the lower limbs, but could slowly creep forward by the upper limbs. In the first 3 days, the rats had poor appetite and few activity, with tail suspension at night there were no ischemia and necrosis of the limb fracture. At 4 weeks, one rat in simple femoral fracture group died, while four rats in femoral fracture merging spinal cord injury group died, with the survival rate of 83.33%, intramedul ary fixation were not prolapsed. In the two groups, continuous bone cal us formation was found in the fracture, and the bone cal us volume in femoral fracture merging spinal cord injury group was significantly higher than those in simple femoral fracture group. The results demonstrated that combining the improved Al en method with smal lateral incision open femoral osteotomy is a simple and feasible method for the establishment of femoral fracture model merging spinal cord injury, and the models survive for 4 weeks.