Abstract
The main problem of modern total hip replacement is the reduction of wear debris. Hence, new tribological partners such as ceramic on ceramic, metal on highly crosslinked polyethylene and metal on metal have evolved. Of these new combinations metal on metal has the longest history. The early problems of high friction using a “micro-fit” between acetabulum and femoral head have been solved by introducing an optimal clearance between the head and the cup to allow for small deformations of the acetabulum during activities without locking. The annual wear rate of metal on metal combinations has been shown to be extremely low ranging from 2 to 5 micrometers/year only. A further advantage of Metasul may be the “wearing in of small scratches” as well as forgiving slight malpositions of the acetabulum, which is not the case in ceramic – ceramic combinations. However, Metasul should not be implanted in patients with renal failure or severe allergies. Metal-metail pairing has proven a valuable alternative in young and active patients over the last 10 years.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
