title: Surface engineering: a low wearing solution for metal-on-metal hip surface replacements.
abstract: Increased patient blood and serum levels of Co and Cr and dissemination of metal wear particles throughout organs and tissues are the primary concerns with metal-on-metal surface replacements. Surface engineering, providing a ceramic bearing surface on a metal substrate, could provide a solution. This study investigated thick (>10 microm) arc evaporation plasma vapor deposition chromium nitride (CrN) coated surface replacements in terms of wear, ion levels, and wear particles in a 10 million cycle hip simulator study, compared to a contemporary metal-on-metal surface replacement. The ion levels were measured by inductively coupled plasma mass spectroscopy. The wear particles were imaged by field emission gun scanning electron microscopy. The CrN-coated bearings had 80% lower wear than the MoM controls. The Cr and Co ion levels in the lubricant of the CrN bearings were 73 and 98% lower than in the MoM controls. The wear particles produced were in the nanometer size range and round to oval in morphology. The CrN coating could provide a reduction in the wear and ion release of MoM surface replacements, thereby reducing the perceived risks to the patient associated with these prostheses.
authors.affiliation: Institute of Medical and Biological Engineering, University of Leeds, Leeds, United Kingdom. I.J.Leslie@leeds.ac.uk
authors.forename: Ian J
authors.initials: IJ
authors.lastname: Leslie
authors.forename: Sophie
authors.initials: S
authors.lastname: Williams
authors.forename: Chris
authors.initials: C
authors.lastname: Brown
authors.forename: James
authors.initials: J
authors.lastname: Anderson
authors.forename: Graham
authors.initials: G
authors.lastname: Isaac
authors.forename: Peter
authors.initials: P
authors.lastname: Hatto
authors.forename: Eileen
authors.initials: E
authors.lastname: Ingham
authors.forename: John
authors.initials: J
authors.lastname: Fisher
mesh_terms: D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods*; D002516:Ceramics / Q000737:chemistry; D002857:Chromium / Q000737:chemistry; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003035:Cobalt / Q000737:chemistry; D006622:Hip Prosthesis; D006801:Humans; D007477:Ions; D008422:Materials Testing; D008670:Metals / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D017672:Nitrogen Compounds / Q000737:chemistry; D011474:Prosthesis Design; D011475:Prosthesis Failure; D013499:Surface Properties
chemical_list: D020099:Coated Materials, Biocompatible; D007477:Ions; D008670:Metals; D017672:Nitrogen Compounds; D002857:Chromium; D003035:Cobalt