Microstructural analysis of trabecular bone and its relation to mechanical properties

Authors examined vertebral trabecular bone (bone withering degree:1) from a woman of 56-year-old. Bone density was measured by DXA and pQCT as an index of bone quantity. From serial images by micro-CT, bone beam number (Tb.N), bone beam interval (Tb.Sp), connectivity density, and fractal dimension were obtained as 3D microstructural indexes. At same time, a nondestructive compression test was done in the 3 directions as head-tail side, inside-outside, and front-back side. The coefficient of elasticity of 3 directions had significantly correlation to bone density and that of the head-tail side direction was significantly higher than those of other 2 directions (p<0.0001). Three dimensional microstructure indexes showed significantly correlation to coefficient of elasticity of 2 directions except the head-tail direction. In 3D microstructure indexes, there was significant correlation to each other. From the coefficient of elasticity of 3 directions and 3D restructured images, it was shown that the examined trabecular bone had anisotropy. (K.H.)