Wimmer, Markus A.Markus A.WimmerNassutt, RomanRomanNassuttSprecher, ChristophChristophSprecherLoos, J.J.LoosTäger, GeorgGeorgTägerFischer, AlfonsAlfonsFischer2018-03-202018-03-202006-02Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine 2 (220): 219-227 (2006-02)http://tubdok.tub.tuhh.de/handle/11420/1593Insufficient understanding of tribological behaviour in total joint arthroplasty is considered as one of the reasons for prosthesis failure. Contrary to the continuous motion input profiles of hip simulators, human locomotion contains motion interruptions. These occurring resting periods can cause stick phenomena in metal-on-metal hip joints. The aim of the present study was to investigate the tribological sensitivity of all-metal bearings to motion interruptions on in vitro test specimens and retrieved implants. Friction and wear with and without resting periods were quantified. Unlike the metal-on-polyethylene joints, the static friction of metal-on-metal joints increased up to micros = 0.3 with rest, while wear appeared to be unaffected. This effect is caused by the interlocking of firmly adhered carbon layers, which were generated from the protein-containing lubricant through tribochemical reactions. Since more than 80 per cent of the retrieved implants exhibited macroscopically visible carbon layers, the increase in friction presumably also occurs under physiological conditions, which is then transferred to the bone-implant interface. These recurrent tangential stress peaks should be considered for the design features of the cup-bone interface, in particular when larger-sized implant heads are used.en2041-303320062219227Sage Publicationshttp://rightsstatements.org/vocab/InC/1.0/Biocompatible MaterialsEquipment Failure AnalysisFrictionLubricationMaterials TestingParticle SizeProsthesis DesignSurface PropertiesTime FactorsVitalliumHip ProsthesisProsthesis FailureMedizinJournal Articleurn:nbn:de:gbv:830-8821995910.15480/882.159011420/159310.1243/09544119JEIM11710.15480/882.1590Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich. This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Journal Article