A survey on the prevalence of pseudotumors with metal-on-metal hip resurfacing in Canadian academic centers

J Bone Joint Surg Am. 2011 May;93 Suppl 2:118-21. doi: 10.2106/JBJS.J.01848.


Background: Metal-on-metal bearings for hip arthroplasty have been in clinical use for over twenty years with excellent clinical results reported worldwide. A small percentage (<1%) of patients have developed an inflammatory response, and a more severe inflammatory response termed pseudotumor has been more recently reported. The primary purpose of this study was to determine the prevalence of pseudotumor following metal-on-metal hip resurfacing in Canadian academic centers.

Methods: Nine of the fourteen centers that perform metal-on-metal hip resurfacings were surveyed. The number of metal-on-metal hip resurfacing arthroplasties performed at each center was determined, as was the number of patients who presented with a pseudotumor and subsequently required revision hip surgery between 2002 and December 2008.

Results: At the nine centers, 3432 hip resurfacing arthroplasties were performed; 76.9% of the patients were male, the mean age was 51.2 years (range, sixteen to eighty-three years), and the mean body-mass index was 28.1 (range, 17 to 55). The mean length of follow-up was 3.4 years (range, two to nine years). A pseudotumor developed after four of the 3432 arthroplasties, for a prevalence of 0.10%.

Conclusions: Although pseudotumors remain a concern after metal-on-metal hip resurfacing, the prevalence at short to midterm follow-up is very low in this multicenter survey. Continued close monitoring is required to determine what clinical factors are involved with the uncommon pseudotumor formation.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Arthroplasty, Replacement, Hip / adverse effects*
  • Canada / epidemiology
  • Female
  • Follow-Up Studies
  • Foreign-Body Reaction / epidemiology*
  • Foreign-Body Reaction / surgery
  • Granuloma, Plasma Cell / epidemiology*
  • Granuloma, Plasma Cell / surgery
  • Hip Prosthesis / adverse effects*
  • Humans
  • Male
  • Metals
  • Middle Aged
  • Prevalence
  • Reoperation
  • Surface Properties


  • Metals