THE EVALUATION OF PREFERENTIAL ALIGNMENT OF BIOLOGICAL APATITE (BAp) CRYSTALLITES IN BONE USING A TRANSMISSION X-RAY DIFFRACTION METHOD

A two-dimensional quantitative XRD measurement of the orientation of biological apatite (BAp) in an isolated trabecula of a mouse ulna was made using a transmission mode X-ray diffraction system with a 0.3 mm diameter parallel beam MoKα source. The same measurement was done with CuKα radiation. Copper Kα is the most commonly used radiation for powder diffraction because it provides good resolution of the resultant lines but is more cumbersome because it requires slicing the bone into thin sections since CuKα radiation is not very penetrating. The preferred orientation of the BAp c-axis from the orecranon to the caput ulnae was measured for 12-week mutant osteopetrotic (op/op) and littermate mice. It was found that the transmission optical method using MoKα radiation provides a simple and non-destructive method for measuring bone quality.