CONTRIBUTIONS OF PORE VOLUME FRACTION AND MINERALIZED MATRIX ELASTICITY TO MILLIMETER-SCALE CORTICAL BONE ELASTIC COEFFICIENTS

Mathilde Granke, Quentin Grimal, Amena Saıed, Pascal Laugier

Keywords

Bone; homogenization; effective properties; cortical;anisotropy; porosity

Abstract

At the millimeter scale, cortical bone is considered to be a mineralized matrix pervaded by roughly cylindrical pores. In a former study we measured the vascular porosity and the millimeter scale elasticity of 21 human cortical bone samples (10 donors). We found that the porosity (pore vol- ume fraction) accounts for a large part, but not all, of the elasticity variations. In the present work, we revisit the data and try to determine which characteristics of the pore net- work or of the mineralized matrix have an influence on the millimeter-scale elasticity. Apparent elasticity predictions obtained with (1) an analytical model with idealized pore shapes and (2) a finite element model accounting for some details of the pore network, are compared to experimental values. The main finding is that for a fixed porosity, the specific distribution of the pores play a minor role in the elasticity values. In contrast, relatively small variations of the mineralized matrix elasticity (±5%) have a measurable impact on millimeter-scale elasticity. The results of this study will serve as a guideline to build sample-specific cor- tical bone models. This will be of interest to analyze the structure-function relationship in bone and to design bone mimicking materials.

Important Links:

Go Back