The chemical form of metallic debris in tissues surrounding metal-on-metal hips with unexplained failure

DOI: 10.1016/j.actbio.2010.06.006

Authors: Alister Hart (Imperial College) , Paul Quinn (Diamond Light Source) , Barry Sampson (Imperial College) , Ann Sandison (Charring Cross Hospital) , Kirk Atkinson (Nuclear Department Defence Academy College of Management & Technology) , John Skinner (Royal National Orthopaedic Hospital) , Jonathan Powell (Medical Research Council Human Nutrition Research Centre) , Fred Mosselmans (Diamond Light Source)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Acta Biomaterialia

State: Published (Approved)
Published: June 2010

Abstract: Implant-derived material from metal-on-metal (MOM) hip arthroplasties may be responsible for an unexplained tissue inflammatory response. The chemical form of the metal species in the tissues is predominantly chromium (Cr), but the currently used techniques have not been able to determine whether this is Cr(III) phosphate or Cr(III) oxide. The analytical challenge must overcome the fact that the metal in the tissues is at a relatively low concentration and tissue preparation or the microscopy beam used can affect the results. Microfocus X-ray spectroscopy using a synchrotron beam is useful in addressing both these issues. Using this technique we compared tissue from failed MOM hips with: (1) tissue from metal-on-polyethylene (MOP) hips; (2) chemical standards; (3) metal discs cut from MOM hips. The most abundant implant-related species in all MOM hip tissues contained Cr. Comparison with standards revealed the chemical form was Cr(III) phosphate, which did not vary with manufacturer type (four types analysed) or level of blood metal ions. Cobalt (Co) and molybdenum (Mo) were occasionally present in areas of high Cr. Co was normally found in a metallic state in the tissue, while Mo was found in an oxidized state. The variety of metallic species may have arisen from corrosion, wear or a combination of both. No evidence of Cr(VI) was seen in the tissues examined.

Journal Keywords: Metal Ion Toxicity; Hip Arthroplasty; Electron Beam; Corrosion Product; Wear Debris

Subject Areas: Biology and Bio-materials


Instruments: I18-Microfocus Spectroscopy