THEORETICAL MODELLING OF CORRELATION BETWEEN BONE ELASTIC MODULUS AND BONE MINERAL DENSITY

In CT-mage based finite element method, the variational elastic moduli E of human bone can be evaluated from the bone mineral density (BMD) values which can be estimated from CT values.Therefore, historically, some empirical formulae correlating E values and BMD have been proposed on the basis of experimental results, while there are no theoretical models correlating E values and the structural parameters.In the present study, theoretical models were developed to correlate E values and BMD along with the mechanical and structural properties of carbonate apatite and collagen.The theoretical models were then validated by comparing the empirical formulae derived by Keyak and Keller and by considering the effects of osteoporosis and osteopenia.It was found that the variational tendencies of E values with increasing BMD obtained from the theoretical models were basically consistent with the empirical formulae of Keyak and Keller, suggesting that the relationship can be well predicted by using the macroscopic models, and the effects of bone quality on the relationship can be controlled by using the microscopic model.