Sequential Alterations in Callous Compositions at a Presumably Stabilized Fracturesite in Rats

Introduction Various compounds are being sought to increase fracture healing and enhance the healing rate. The closed femoral fracture in rats is a model commonly used to assess the efficacy of a compound for healing. This model is considered as a presumably stabilized fracture healing process. In a normal fracture healing process, there are 4 stages, i.e., inflammatory reaction and hematoma immediately after fracture, perio steal and endosteal callus formation, development of osteogenic repair tissue, and bone remodeling. The compositions in the transitional callus through these stages have not been analyzed microscopically in a sequential mode post-fracture. The revelation of compositional alterations is crucial for determining the time and the frequency of administering a compound. This experiment examined the alterations at weekly interval up to 8 weeks after a femoral closed fracture was created in aged male rats.