PHYSICAL MEANING OF BONE-MINERAL CONTENT PARAMETERS AND THEIR RELATION TO MECHANICAL-PROPERTIES

The relations between parameters obtained by clinical absorptiometric techniques, such as SPA, DPA, DXA and QCT, and geometrical and materia l parameters of bone structures are investigated. Two types of bone ar e considered: the diaphysis of a long bone, modelled as a hollow cylin drical structure consisting of compact bone, and secondly a cylindrica l body consisting of trabecular bone. The latter is a model for the ve rtebral body and for the femoral neck. Parameters investigated are BMD (as gr/cm2) and BMC (as gr/cm). The modeling predicts good agreements between BMD and the wall thickness in the diaphysis of the bone, betw een BMC and the area of cross section of a long bone and between BMC a nd the effective area in a body of trabecular bone.