Heterogeneous Femur Model Reconstruction for Improved FEA Analysis

Abstract

The objective of this research is to reconstruct the femur bone as a heterogeneous model and to examine the mechanical response of the proximal femur bone under mechanical loading using finite element analysis. Contrary to setting a uniform Young’s modulus for the femur bone during analysis, the femur bone was reconstructed as a layered heterogeneous model with each layer having its own assigned Young’s modulus. Computerized Axial Tomography (CT) slices of a fresh frozen femur of a 30 year old male donor were downloaded from (www.bgu.ac.il/~zohary/CT_FF.html) which was uploaded by Yosibash et al. [1]. The images were imported into MIMICS 11.02 and used to convert 2-D CT scans into a layered 3-D Stereolithography (STL) image. The proximal femur was divided into ten layers in the longitudinal direction of the proximal femur based on their Hounsfield unit (HU) values. The Hounsfield unit obtained from MIMICS was used to calculate the density of the bone as well as the corresponding Young’s modulus. Constant Poisson’s ratio of 0.3 was used in the simulation. It is hypothesized that by including the variation in density within the finite element analysis model (FEA), it would be possible to replicate the experimental results obtained by Yosibash et al