Influence of different methods of internal bone fixation on characteristics of bone callus in experimental animals.

INTRODUCTION Correct choice of osteosynthesis method is a very important factor in providing the optimal conditions for appropriate healing of the fracture. There are still disagreements about the method of stabilization of some long bone fractures. Critically observed, no method of fracture fixation is ideal. Each osteosynthesis method has both advantages and weaknesses. OBJECTIVE The objective of this study was to compare the results of the experimental application of three different internal fixation methods: plate fixation, intramedullary nail fixation and self-dynamisable internal fixator (SIF). METHODS A series of 30 animals were used (Lepus cuniculus) as experimental animals, divided into three groups of ten animals each. Femoral diaphysis of each animal was osteotomized and fixed with one of three implants. Ten weeks later all animals were sacrificed and each specimen underwent histological and biomechanical testing. RESULTS Histology showed that the healing process with SIF was more complete and bone callus was more mature in comparison to other two methods. During biomechanical investigation (computerized bending stress test), it was documented with high statistical significance that using SIF led to stronger healing ten weeks after the operation. CONCLUSION According to the results obtained in this study, it can be concluded that SIF is a suitable method for fracture treatment.