Pole figure analysis of mineral nanoparticle orientation in individual trabecula of human vertebral bone

The spongious interior of human vertebral bone consists of interconnected trabecula with a thickness of about 0.2 mm. The texture of the bone material, a collagen-mineral nanocomposite, was studied within single trabecula by collecting two-dimensional small-angle X-ray scattering (SAXS) and X-ray diffraction (XRD) data exactly at the same specimen positions with an X-ray beam of 0.2 mm diameter. Three-dimensional information was reconstructed by combining measurements with different specimen orientations. The XRD data, and for the first time also the SAXS data, were subjected to a pole figure analysis. The method provides a quantitative description of the crystallographic orientation distribution as well as the morphological orientation distribution of the plate shaped nanoparticles, both with respect to the orientation of the investigated trabecula. As a main result it could be shown that a fibre-texture exists in the trabecula, and that the plate shaped nanoparticles are aligned with the lamellae within the trabecula.