Development of Numerical Stress Analysis Technique for human Joints and its Artificial Replacements

In this preliminary study the variations of stress-distribution are analysed in different human joints using two-dimensional finite element technique. The aim is to develop a generalised programme for any type of human joint and can be used withs uitable for the data element properties. The mathematical model accommodates experimentally measured spatial variations of the bone stiffness of different joints. Such spatial variations in bone-stiffness emphasise the inherent inhomogeneity and anistropy of bone structure. This application of two dimensional finite elment technique also analyses the human joint reconstruction with artificial prosthesis fixed with polymethyl methacrylate. It includes the solution of stress field at various locations of the reconstruction zone. The analysis of stress field will explain the different modes of failure of the bone-cement bond and the cement prosthses bond. Computer analysis of stress pattern will suggest a possible cause for disruption of blood supply in some parts of human joints. This of course helps osteotomy, to redistribute the mechanical stresses in a favourable manner to provide uninterupted blood supply. Also it will help to improve the design of better prosthesis and characterise the requirement of ideal bone cement.