Holographic interferometry

Abstract

The complex nature of bone structure constitutes one of the major problems in the investigation of mechanical systems in orthopaedics. Not only does the macroscopic architecture of the bones have to be considered, with the external and internal shapes of the bones differing from bone to bone, but also the complex anisotropy of cortical bone makes the mechanical properties difficult to model. In research into the fundamental aspects of orthopaedic practice, it is the analysis of the deformation which is of interest, whether it is of the bone itself, of an implant or of a composite system of a bone with an implant. If the loading conditions of the bone are massively disturbed then the bone will remodel to adjust to the new conditions and this frequently leads to a reduction in the stability of the implant—bone system as a result of extensive bone resorption. It is common for surgeons to attach overdesigned implants into the body, creating a large distortion in the loading patterns on the bone. Problems may occur in the months and years following implantation as the bone adapts its structure accordingly.