Scanning texture analysis of lamellar bone using microbeam synchrotron X-ray radiation

Texture analysis with microbeam scanning diffraction enables the local mapping of three-dimensional crystallite orientation in heterogeneous natural and synthetic materials. Cortical (compact) bone is an example of a hierarchically structured biocomposite, which is built mainly of cylindrical osteons, having a lamellar texture at the micrometre level. In this work, a combination of microbeam synchrotron X-ray texture analysis with thin sections of osteonal bone is used to measure the three-dimensional distribution of the c-axis orientation of the mineral apatite in bone with positional resolution of 1 µm. The data reduction procedure needed to go from the stereographic projection of X-ray intensity to the determination of the local orientation of mineralized collagen fibrils is described. The procedure can be applied to other mineralized tissues (such as trabecular bone and chitin) with micrometre scale and biologically controlled fibrillar texture.