Objectives
One commonly used rat fracture model for bone and mineral research is a closed mid-shaft femur fracture as described by Bonnarens in 1984. Initially, this model was believed to create very reproducible fractures. However, there have been frequent reports of comminution and varying rates of complication. Given the importance of precise anticipation of those characteristics in laboratory research, we aimed to precisely estimate the rate of comminution, its importance and its effect on the amount of soft callus created. Furthermore, we aimed to precisely report the rate of complications such as death and infection.
Methods
We tested a rat model of femoral fracture on 84 rats based on Bonnarens’ original description. We used a proximal approach with trochanterotomy to insert the pin, a drop tower to create the fracture and a high-resolution fluoroscopic imager to detect the comminution. We weighed the soft callus on day seven and compared the soft callus parameters with the comminution status.
Background: Bacterial translocation is defined as a phenomenon in which live bacteria cross the intestinal barrier and spread the other systemic organs after various type of traumatic insults such as hemorrhagic shock, burn, malnutrition and abdominal trauma. It has also been shown that multiple fractures of long bones associated with head injury promote bacterial translocation. Aim: To determine whether early internal fixation of long bone fractures helps to prevent bacterial translocation. Materials and methods: Thirty-seven male Sprague-Dawley rats were divided into three groups. 1) anesthesia only (control group, n=12); 2) anesthesia + tibia fracture + femur fracture + moderate head trauma (trauma group, n=14), and 3) anesthesia + fixation of both tibia and femur fractures + moderate head trauma (fixation group, n=11). Head injury was created by using Marmarou’s impaction-acceleration model and fractures were created by using a