Bone healing models in rat tibia after different injuries

Abstract

Aims: Gradual elaboration of an adequate and efficient multistage method for experimental remodelling of specific wound healing process--bone repair. Comparison of clinical characteristics with the results of microanatomy, histology, electronmicroscopy and computer morphometry.

Material and methods: An investigation of posttraumatic bone repair after internal fracture, excision and cortical perforation was carried out on 142 young adult male Wistar rats. The repair was studied in normal and affected animals (exercises, immobilization, isolation of periost) at 1-42 days after operation.

Results: The posttraumatic bone callus development and the related soft tissue repair, likewise the continuous remodelling, is an ordinary process of osteohisto- and organogenese. In trained rats the blood supply and bone formation is increased, whereas in immobilized animals it is inhibited and destroyed (osteoporose, pseudoarthrosis). After the injury some characteristics of bone repair histogenese will be became evident (after the perforation the primary endosteal and secondary periosteal ossification, inhibition of endosteal bone repair after the isolation of periost etc.).

Conclusion: The posttraumatic bone healing, like embryohistogenese, has similar repair stages in all models of the experiments as well as similar tissue and cell responses (callus formation, its replacement, bone remodelling, etc.). However, the repair process in general (order of chondrous and/or bone callus stages, etc.) is variable and dependent on the mode and degree of injury. The use of bone cortex perforation in wound healing study is more recommendable as compared to internal fracture and excision (possibility of in situ study the periost and callus tissue compartments in bone repair machinery separately).