Abstract
Summary: The tribological development in the metal-metal partners brought out a new surface texture for the femoral cup. A reduction of the coefficient of friction and a reduction of the metallic abrasion on almost half are secured in lab tests. First clinical applications took place in our hospital.
Question: Total hip surface replacement in metal-metal partners have, although in small quantity, metallic abrasion, which leads to clear increases of the serum concentration of the serological level. The long-term effect on the organism is not so far clarified. A reduction of the abrasion quantity is however worthwhile. Is a structural change of the surface of the femoral cup suitable to cause such a reduction of the metallic abrasion?
Methodology: Derived from bionic systems in nature the surface of total hip surface replacement was changed by dimple like surface, so that in presence of liquid an accumulation of liquid between both sliding partners takes place and takes place thus on this liquid film the articulation. Laboratory tests on a simulator were accomplished, in order to examine whether the desired reduction of the abrasion is obtained. This surface is called Biosurf-surface.
Results: Simulator wear tests of the standard total hip surface replacement in the metal-metal partner have been compared with the Biosurf-surface. The simulator attempts showed that after 5 million motion cycles the Biosurf –system the abrasion quantity in milligram reduces to more than a half. By this clear reduction of particles the concentration of the metal ions which can be expected in the serum is clearly smaller, so that thereby a contribution is made to reduce the possibly damaging influence of metallic ions in the organism.
Correspondence should be addressed to ERASS Office, Schulthess Klinik, Lengghalde 2, CH-8008 ZURICH, Switzerland.
