Reduced UHMWPE wear using magnesia-stabilized zirconia instead of CoCr femoral components in a knee simulator

J Arthroplasty. 2015 Mar;30(3):468-74. doi: 10.1016/j.arth.2014.09.027. Epub 2014 Oct 2.

Abstract

Magnesia-stabilized zirconia (Mg-PSZ) is stable and maintains a scratch-resistant surface in hip replacement, but is untested in knees. We assessed whether using Mg-PSZ instead of cobalt-chromium (CoCr) femoral components resulted in less tibial insert wear, and evaluated changes in topography and roughness of the femoral components. Inserts bearing against CoCr or Mg-PSZ were tested using standard (9 Mc) and aggressive (6 Mc) waveforms. Femoral component surface topography and roughness were evaluated before and after testing by optical profilometry. When bearing against Mg-PSZ, UHMWPE wear rate decreased by 73% (standard) and by 59% (aggressive conditions). After 15 Mc, CoCr components featured deep scratches, and roughness increased five-fold, while Mg-PSZ components were unchanged. Mg-PSZ femoral components may be indicated for high-demand patients and those with metal sensitivity.

Keywords: ceramic; cobalt chromium; roughness; total knee arthroplasty; wear.

Publication types

  • Comparative Study
  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biocompatible Materials
  • Chromium
  • Cobalt
  • Computer Simulation
  • Femur / surgery*
  • Humans
  • Knee Joint / surgery*
  • Knee Prosthesis*
  • Magnesium Oxide
  • Polyethylenes
  • Prosthesis Design
  • Prosthesis Failure
  • Tibia / surgery
  • Zirconium

Substances

  • Biocompatible Materials
  • Polyethylenes
  • ultra-high molecular weight polyethylene
  • Chromium
  • Magnesium Oxide
  • Cobalt
  • Zirconium
  • zirconium oxide