Trabecular Bone Poroelasticity For MicroCT-based FE models

Abstract

A useful mathematical model that describes the mechanical behavior of bone is the poroelastic model. So far, numerical studies of trabecular bone poroelasticity have considered the tissue as a homogeneous porous structure. The objective of this study was to develop a methodology for creating large-scale finite element models that predict the poroelastic response of trabecular bone, including the tissue micro-architecture. 1 cm3 cubes of bovine trabecular bone were scanned using micro-computed tomography. Finite elements models were developed using different voxel and sample sizes. Strain equivalent to 1% of deformation was applied at three different rates and confined and unconfined conditions were simulated. Stress distributions in the bone phase were similar under confined and unconfined conditions. The fluid velocity and the pore pressure in the marrow were higher under confined than under unconfined conditions. The trabecular bone stiffness was higher under confined compared to under unconfined conditions, increasing with increments in the strain rate. Variations in the sample size were more significant in the predicted stiffness than variations in the voxel size. This study included both the poroelasticity and the micro-architecture of trabecular bone to predict changes in the mechanical response of trabecular tissue under time-dependent loading conditions.