title: Graphitic tribological layers in metal-on-metal hip replacements.
abstract: Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical role and that there is a tribological layer on the metal surface. We report evidence for graphitic material in the tribological layer in metal-on-metal hip replacements retrieved from patients. As graphite is a solid lubricant, its presence helps to explain why these components exhibit low wear and suggests methods of improving their performance; simultaneously, this raises the issue of the physiological effects of graphitic wear debris.
authors.affiliation: Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60201, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Liao
authors.forename: R
authors.initials: R
authors.lastname: Pourzal
authors.forename: M A
authors.initials: MA
authors.lastname: Wimmer
authors.forename: J J
authors.initials: JJ
authors.lastname: Jacobs
authors.forename: A
authors.initials: A
authors.lastname: Fischer
authors.forename: L D
authors.initials: LD
authors.lastname: Marks
mesh_terms: D000818:Animals; D019644:Arthroplasty, Replacement, Hip; D001672:Biocompatible Materials; D002417:Cattle; D003343:Corrosion; D017276:Friction; D006108:Graphite / Q000032:analysis*; D006622:Hip Prosthesis / Q000009:adverse effects; D006801:Humans; D053768:Metal Nanoparticles; D011474:Prosthesis Design; D011475:Prosthesis Failure; D044967:Serum; D046590:Spectroscopy, Electron Energy-Loss; D013059:Spectrum Analysis, Raman; D013499:Surface Properties; D014800:Vitallium
chemical_list: D001672:Biocompatible Materials; D014800:Vitallium; D006108:Graphite