Inverse Finite Element Modeling for Characterization of Local Elastic Properties in Image Guided Failure Assessment of Human Trabecular Bone

Abstract

The local interpretation of microfinite element (خ¼FE) simulations plays a pivotal role for studying bone structure–function relationships such as failure processes and bone remodeling. In the past خ¼FE simulations have been successfully validated on the apparent level, however, at the tissue level validations are sparse and less promising. Furthermore, intratrabecular heterogeneity of the material properties has been shown by experimental studies. We proposed an inverse خ¼FE algorithm that iteratively changes the tissue level Young’s moduli such that the خ¼FE simulation matches the experimental strain measurements. The algorithm is setup as a feedback loop where the modulus is iteratively adapted until the simulated strain matches the experimental strain. The experimental strain of human trabecular bone specimens was calculated from timelapsed images that were gained by combining mechanical testing and synchrotron radiation microcomputed tomography (SRخ¼CT). The inverse خ¼FE algorithm was able to iterate the heterogeneous distribution of moduli such that the resulting خ¼FE simulations matched artificially generated and experimentally measured strains.