Micro-Mechanical Characterisation of Human Cortical Bone

We present a numerical model to mechanically characterise real and Monte-Carlo microstructures of human cortical bone. Femoral mid-shaft human bone microstructures are specific to each individual and exhibit unique morphological and mechanical properties. Real microstructures of female bone samples are explicitly reconstructed using a finite element model. Patient-dependent statistically equivalent models are built from natural morphological parameters measured under reflected light microscopy (RLM) and back-scattered electron microscopy (BSEM). The micro mechanical properties are provided by nanoindentations and microextensometry. The morphological and mechanical characteristics are incorporated into the model to mimic bone micro-scale heterogeneity. The overall stiffness of the microstructure is calculated for a distribution of samples. The effects of the variations of local parameters on the global stiffness are studied. The evolution of these parameters indicates various aging signs of bone. These results are validated through comparison to experiments to assess fracture risk.