Morgan Matroc
Ltd, Bioceramic Products use LUSAS Analyst for stress analysis of ceramic
components such as femoral heads used in total hip replacement. In orthopaedic
applications, ceramic heads offer the advantages of low wear, high strength and excellent
biocompatibility. Morgan Matroc is a world leader in ceramic technology and always uses
the most up-to-date techniques to evaluate, design and test their ceramic implant devices.
The ceramic heads are made of either zirconia or alumina and are highly polished to
reduce wear on the hip socket, which is made from Ultra High Molecular Weight Polyethylene
(UHMPE). The head is fitted to a Morse-type taper titanium shaft that is then cemented
into the femur. The heads are produced in a range of sizes with bore sizes and taper
angles adjusted according to customer requirements. LUSAS is being used to investigate
load-to-failure, fatigue and impact for these various configurations.
Normally, the analysis of the contact between the shaft and head and between
head and socket is a very difficult problem for traditional finite element systems.
However, LUSAS Analyst contains a "slideline" facility specifically designed for
these types of contact problem. The slideline facility automatically calculates the
contact conditions between the various parts in the structure and allows complex problems
involving contact and friction to be modelled and analysed with relative ease.