Elastic modulus and nanostructure of the plate- and rod-like trabeculae in bovine proximal femurs

Trabecular morphology correlates with the stiffness and strength of the cancellous bone. The present study aims to investigate the differences in the elastic modulus and nanostructure between the rod- and plate-like trabeculae. We dissected 37 rod-like and 11 plate-like trabeculae from the proximal cancellous bone of 2-year-old bovine femurs. The elastic modulus was measured by tensile and micro-cantilever bending tests and that of the rod- and plate-like trabeculae was 10.6±4.9 and 8.5±2.5 GPa, respectively, with no significant difference. Furthermore, we measured the c-axis orientation of hydroxyapatite crystals in the tissue using X-ray diffraction and calculated the degree of orientation. No significant difference was noted in the degree of orientation between the rod- and plate-like trabeculae. The present study demonstrates that the elastic modulus of a single trabecula and its causal nanostructure were independent to the trabecular morphology in bovine femurs.