Currently available finite element (FE) models of intertrochanteric fractures cannot accurately represent the real material properties of femurs. This paper aimed to create and validate an FE model of intertrochanteric fractures with inhomogeneous material properties assigned from CT images by a node-based approach. The geometry of a femur was automatically generated from its CT images. The density and Young’s modulus were assigned to the FE model via an in-house program. The fractured femur was fixed with a dynamic hip screw (DHS) system. The resonant frequencies of the intact femur were calculated by finite element analyses (FEA) and then compared with the existing experimental results. The strains at the femoral neck and the lesser trochanter and the reaction forces under compression were also investigated by the finite element analysis. These simulation results were validated by in vitro experimental tests. In addition, the FE model with homogeneous material properties was used for comparison. Relative error analyses showed that the FE predictions matched the experimental results very well (as the errors of all the four indexes were lower than 10%), which meant that the node-based inhomogeneous material model was accurate and that the FE model could be used to investigate the intertrochanteric fractures.
This research was partially supported by the project (No.31470908) of the Natural Science Foundation of China and the project (No. 2016YFE0117200) of China - Singapore joint research program.
This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)