RABBIT BONE TISSUE RESPONSE TO THE DEFECTS TREATED WITH DIFFERENT FIXATION METHODS

Blood supply and stabilization at the fracture site are two essential factors in fracture healing. Different fixation methods may enable different conditions of stability needed for fracture healing. The aim of this study was to determine, by histological tissue analysis, whether different methods of fixation and biomechanical characteristics of osteosynthetic material have an effect on the bridgeable tissue characteristics and the rate of the healing of defects of long bones in experimental animals. Experimental procedure was performed on twenty-one Chinchilla rabbits. Artificially created bone defects were treated in one of the following ways: with a plate, an internal fixator and an external fixator. Six weeks after surgery, the results of histological analysis showed that union was started in all examined samples. When a plate was used for fixation, fibro-cartilaginous healing stage was marked clearly with high levels of activity. In the defects treated with selfdynamisable internal fixator, the woven bone tissue was seen indicating the bony callus formation. When external fixator was used for fixation, the effect was comparable with that seen in the defect side treated with selfdynamisable internal fixator. Based on the results obtained in our study, we can conclude that biomechanical characteristics of internal and external fixators are more superior than biomechanical characteristics of a plate in the treatment of bone defects in experimental animals. Acta Medica Medianae 2018;57(4):36-42.