摘要:
A composite socket of a joint endoprosthesis may be fashioned in which the inorganic component of the socket has apatite and/or wollastonite crystalline phases and additionally secondary crystalline phases providing improved hydrolysis stability. The inorganic mixture consists (in mass % proportions) of 31-34% CaO, 10-12% P.sub.2 O.sub.5, 43-46% SiO.sub.2, 3-5% Na.sub.2 O, 2-3% CaF.sub.2 and, beyond the 100% of the above components, also 0.5-11% Al.sub.2 O.sub.3 and/or Zr.sub.2 and Al.sub.2 O.sub.3 or TiO.sub.2 and ZrO.sub.2 or TiO.sub.2 and ZrO.sub.2 and Al.sub.2 O.sub.3, whereby the proportion of TiO.sub.2 lies between 0.5 and 5%. Essential to the invention, too, is a certain grain size distribution and radius of aperture between the ball and the socket. The result is non-wearing operation of the endoprosthesis.