title: Wear of composite ceramics in mixed-material combinations in total hip replacement under adverse edge loading conditions.
abstract: Ceramic composites have performed very well under adverse edge loading conditions when used in like-on-like configurations, where the femoral head and acetabular cup are of the same material. The aim of this study was to determine the wear of pure alumina (Al2O3), alumina toughened zirconia (ATZ) and zirconia toughened alumina (ZTA) when used in mixed bearing combinations, under edge loading conditions due to translational mal-positioning. The head-on-cup configurations of three ceramic materials were ATZ-on-ZTA, ZTA-on-ATZ, Al2O3-on-ATZ, ATZ-on-Al2O3, Al2O3-on-ZTA, and ZTA-on-Al2O3. They were tested on the Leeds II hip simulator under microseparation conditions. The bedding in and steady state wear rates of ATZ-on-ZTA were 1.16mm3/million cycles and 0.18mm3/million, respectively, and for ATZ-on-Al2O3were 0.66 mm3/million cycles and 0.20 mm3/million, respectively. The wear rates of the other bearing combinations under these adverse microseparation conditions, Al2O3-on-ATZ, Al2O3-on-ZTA, ZTA-on-ATZ and ZTA-on-Al2O3were very low with no clear bedding in and steady state phases, and with steady state wear rates lower than 0.11 mm3/million. The mixed material combinations tested in this study have shown slightly higher wear rates when compared to ATZ in like-on-like configuration reported previously, but superior wear resistance when compared to alumina-on-alumina bearings tested previously under the same adverse microseparation conditions. © 2016 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1361-1368, 2017.
authors.affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Mazen
authors.initials: M
authors.lastname: Al-Hajjar
authors.affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Silvia
authors.initials: S
authors.lastname: Carbone
authors.affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: Louise M
authors.initials: LM
authors.lastname: Jennings
authors.affiliation: Mathys Orthopädie GmbH, Moersdorf, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Begand
authors.affiliation: Mathys Orthopädie GmbH, Moersdorf, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Oberbach
authors.affiliation: Mathys AG Bettlach, Bettlach, Switzerland.
authors.forename: Daniel
authors.initials: D
authors.lastname: Delfosse
authors.affiliation: Institute of Medical and Biological Engineering, School of Mechanical Engineering, University of Leeds, Leeds, UK.
authors.forename: John
authors.initials: J
authors.lastname: Fisher
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D002516:Ceramics / Q000737:chemistry*; D006622:Hip Prosthesis; D006801:Humans; D008422:Materials Testing; D016474:Weight-Bearing
keywords: ceramic on ceramic; edge loading; hip replacement; microseparation; stripe wear