Bone Mineral Quality

The main function of bone is to promote locomotion and protection of vital organs. Bone is also an important mineral ions reservoir, essential to maintain phosphocalcic homeostasis. Bone mineral is a calcium phosphate named “apatite”, which form naturally in the Earth’s crust (Wopenka & Pasteris 2005). Compared to others minerals, apatite is more “tolerant” and is very accommodating to chemical substitutions. This ability to easily absorb ions confers to bone a detoxification property, with some ions normally absent of bone and which are captured by bone mineral. But the substitutions in bone mineral change the structure of apatite, conferring to bone several properties such as solubility, morphology, hardness, strain etc. Thanks to those remarkable properties, bone has the ability to continually adapt to changes to its mechanical environment (Bouxsein 2005). Bone is an anisotropic composite material tissue, and highly hierarchical viscoelastic (Bouxsein 2005). When a load is applied to bone, this produces energy, and as this energy can not be destroy, the bone has to absorbed it (Seeman & Delmas 2006). The elastic properties of bone allow to absorb this energy by deforming reversibly. But if the load exceeds the ability of the bone to carry this load, it can deform permanently by plastic deformation (Fig.1). This produces microcracks allowing