Prediction of the fixation conditions of murine fracture fixation plates

Abstract

For new medical materials to be approved for implantation in the human body, they must undergo extensive animal experiments. In this study, the fixation states of a newly developed murine fracture fixation plate were evaluated. After producing a complex finite element model composed of a mouse femur and two types of fracture plate with differing rigidity, the levels of inter fragment movement, strain, and stress in the fracture area were analyzed under three types of loading condition. The fixation conditions were evaluated by predicting bone conditions based on the values of strain and stress, using the rule of remodeling. The level of inter fragment movement was higher with flexible plates whose rigidity was low compared with rigid plates whose rigidity was high. Osteogenesis was confirmed at more measurement sites with flexible than with rigid plates. It was suggested that the fixation states are better in flexible fixation with low-rigidity plates compared to strong fixation with high-rigidity plates.