Mechanical Evaluation of Fracture in the Proximar Femur during Falls and Development of Hip Protector

点击翻译按钮获取中文摘要

In the present study, in order to examine the cause of hip fracture by falls, we performed the following studies : 1) experiments to simulate falls by use of cadaveric femora, 2) finite element analyses to use finite element models created from X ray computed tomographic images of cadaveric femora, 3) construction of the system creating finite element models for individual femora. The results obtained are summarized as follows :1. Static loads were applied to cadaveric female femora (aged 89-95), and the relation between the fracture risk and the load direction was discussed. The results showed that the stress concentration is observed in the superior subcapital and posterior basicervical regions.2. From the impact tests for 10 cadaveric femora (aged 77-94), it was found that femoral neck fractures are mainly caused by compressive stresses, and that the femoral shapes and bone density influence the type of fracture.3. In the results of the finite element analyses with the model from the left cadaveric femur 65 ages male, the fracture risk on the posterior basicervical region increased with the rotation angle around the diaphyseal axis.4. It was thought that the differences of shapes among specimens had some influences on femoral neck fracture. Hence we developed a method that constructs individual finite element models of proximal femur by using the minimum amount of morphological parameters of femur.5. By this method, we can construct the models in shorter time than before, and moreover it became much easier to perform the finite element analyses taking account of individual femoral shapes.