28 mm Metasul™ bearings in primary total hip arthroplasty

Abstract

Assessment of possible low-wear with some former metal-on-metal (MoM) total hip arthroplasties (THA) led to the reintroduction of metallic bearings in the late 80's. The author reports on two studies of Metasul-28 mm cementless THA. In the first one in a general population, impingement has been the main cause of osteolysis and Co level survey has been a good indicator of Metasul bearing behaviour. In the second study, in a group of 83 less than 50-year-old and active patients, Metasul bearings showed good wear resistance at 7.2 years mean follow-up. In both studies, no general toxic effect could have been detected thus far. According to the current knowledge, it is always reasonable to expect low-wear and better THA longevity with use of MoM bearings under the following conditions: 1) use of a CoCr alloy with high carbide concentration; 2) reduce impingement risk (head without sleeve, slimmer as possible neck, perfectly adapted Morse cone from the same manufacturer, well -oriented components); and 3) prefer cementless acetabular fixation.

Mechanism of Clinical Complication of Metal-on-Metal Total Hip Replacement: Nanoparticle Characterisation, Nanotoxicity, and Biological Metal Corrosion

“…The Metasul module was described as using wrought high-carbon (>0.2%) CoCr alloys which are much smoother than traditional cast alloys. The first generation of this module was designed with a liner rim edge and a head sleeve, but both of them were removed for the second design in 1995 (C Delaunay, 2006). The Metasul design was proved, with low wear rates, improved joint stability and an increased range of motion in many clinical reports at that time (Anissian, Stark, Gustafson, Good, & Clarke, 1999; C. P. Delaunay, 2004).…”