Abstract
In this work bone texture was studied both as a biological tissue and also as a two-phase composite material. The orientation of the apatite in bone was investigated using several X-ray diffraction techniques, including film methods, diffractometry and the Schulz texture goniometer. With the latter self-consistent (002) and (310) computer-plotted pole figures were produced which showed the distribution of the apatite crystals in bone. The shaft of the femur, the humerus and the mandible of healthy bovine bone 1 1/2 years old were used. The distribution of apatite crystals was found to vary only within narrow limits in all the bones investigated. In order to compare the apatite orientation with histological features, microradiographs were produced of sections of femur and humerus in three mutually perpendicular planes. These same sections were then studied under the polarising microscope. A method of estimating the orientation of the fibrils was devised by finding extinction positions of the fibrils when the polariser and analyser were rotated together, keeping the specimen stationary. The fibril orientation was found to vary abruptly within small regions. The main conclusion drawn was that the orientation of the apatite crystals was more organised than the histology of the bone would suggest. It was proposed that the orientation of apatite crystals may be related to the mechanical role of the bones.