Animal Models of Bone Fracture or Osteotomy

The processes of normal and abnormal fracture healing and the various factors affecting them have been widely studied since the days of Galen and Hippocrates. Rabbit tibial fracture is a major fracture model. The fracturing methods used in this model include saw osteotomy, fracture devices, and drill plus bone cutter. Radial osteotomy in rabbits and dogs can be made using a powered saw. Delayed union and nonunion are special types of fractures models, representing abnormal fracture healing. For long bone fractures or osteotomies, healing parameters, such as periosteal reaction (callus formation), quality of union, and bone remodeling are quantitated based on a radiographic scoring system. To evaluate the mechanical properties of bone associated with fracture healing, bending and torsional tests are the most popular. Animal studies have indicated that growth hormone has stimulatory effects on fracture healing. Non-steroidal anti-inflammatory drugs, especially indomethacin, are notorious substances for their inhibition effect on bone growth and fracture healing.