Accuracy of Individual Trabecula Segmentation Based Plate and Rod Finite Element Models in Idealized Trabecular Bone Microstructure

Abstract

Currently, specimenspecific micro finite element (خ¼FE) analysis based micro computed tomography (خ¼CT) images have become a major computational tool for the assessment of the mechanical properties of human trabecular bone. Despite the fine characterization of the threedimensional (3D) trabecular microstructure based on highresolution خ¼CT images, conventional خ¼FE models with each voxel converted to an element are not efficient in predicting the nonlinear failure behavior of bone due to a prohibitive computational cost. Recently, a highly efficient individual trabecula segmentation (ITS)based plate and rod (PR) modeling technique has been developed by substituting individual plates and rods with shell and beam elements, respectively. In this technical brief, the accuracy of novel PR خ¼FE models was examined in idealized microstructure models over a broad range of trabecular thicknesses. The Young's modulus and yield strength predicted by simplified PR models strongly correlated with those of voxel models at various voxel sizes. The conversion from voxel models to PR models resulted in an ∼762fold reduction in the largest model size and significantly accelerated the nonlinear FE analysis. The excellent predictive power of the PR خ¼FE models, demonstrated in an idealized trabecular microstructure, provided a quantitative mechanical basis for this promising tool for an accurate and efficient assessment of trabecular bone mechanics and fracture risk.