title: Damage mechanisms at the cement-implant interface of polished cemented femoral stems.
abstract: The occurrence of damage on polished femoral stems has been widely reported in the literature, and bone cement has been implicated in a tribocorrosive failure process. However, the mechanisms of cement-mediated damage and the impact of cement formulation on this process are not well understood. In this study, 13 Zimmer CPT polished femoral stems, and the corresponding cement specimens were retrieved at revision surgery and analyzed using high-resolution imaging techniques. Surface damage attributed to tribocorrosion was observed on all stems. Corrosion product, in the form of black flaky surface debris, was observed on the surface of cement specimens; both energy-dispersive X-ray spectroscopy and inductively coupled plasma mass spectrometry(ICP-MS) confirmed the presence of cobalt and chromium, with the ICP-MS showing much higher levels of Cr compared to Co when compared to the original stem material. Agglomerates of ZrO2radiopacifier were also identified on the cement surface and, in some cases, showed evidence of abrasive wear; the size of these particles correlated well with elliptical pitting evident on the surfaces of the corresponding stems. This evidence supports the hypothesis that agglomerates of hard radiopacifier particles within the cement may induce a wear-dominated tribocorrosive interaction at the stem-cement interface that damages the surface of polished CoCr femoral stems. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 2027-2033, 2017.
authors.affiliation: Bioengineering Science Research Group, University of Southampton, Southampton, UK.
authors.forename: Natalie
authors.initials: N
authors.lastname: Shearwood-Porter
authors.affiliation: Bioengineering Science Research Group, University of Southampton, Southampton, UK.
authors.forename: Martin
authors.initials: M
authors.lastname: Browne
authors.affiliation: School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK.
authors.forename: James A
authors.initials: JA
authors.lastname: Milton
authors.affiliation: School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Cooper
authors.affiliation: School of Ocean and Earth Science, University of Southampton, National Oceanography Centre, Southampton, UK.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Palmer
authors.affiliation: Southampton Orthopaedic Centre for Arthroplasty and Revision Surgery (SOCARS), Southampton General Hospital, Southampton, UK.
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Latham
authors.affiliation: National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Highfield, Southampton, UK.
authors.forename: Robert J K
authors.initials: RJK
authors.lastname: Wood
authors.affiliation: National Centre for Advanced Tribology at Southampton (nCATS), University of Southampton, Highfield, Southampton, UK.
authors.forename: Richard B
authors.initials: RB
authors.lastname: Cook
mesh_terms: D000328:Adult; D000368:Aged; D000069343:Bone-Implant Interface / Q000473:pathology*; D002858:Chromium Alloys / Q000009:adverse effects*; D003343:Corrosion; D019544:Equipment Failure Analysis; D005260:Female; D005269:Femur / Q000378:metabolism / Q000473:pathology*; D006801:Humans; D016268:Internal Fixators / Q000009:adverse effects*; D008297:Male; D020366:Methylmethacrylate / Q000009:adverse effects*; D008875:Middle Aged
chemical_list: D002858:Chromium Alloys; D020366:Methylmethacrylate
keywords: bone cement; cobalt-chromium alloys; corrosion; failure analysis; implant retrieval