An analysis of the in vivo deterioration of Co-Cr-Mo implants through wear and corrosion

• Published in: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of engineering in medicine Vol. 221; no. 3; p. 291
• Main Authors: Hodgson, A W, Mischler, S, Von Rechenberg, B, Virtanen, S
• Format: Journal Article
• Language: English
• Published: England 2007
• Subjects: Animals; Corrosion; Equipment Failure Analysis; Female; Foreign Bodies - etiology; Foreign Bodies - pathology; Hip Joint - pathology; Hip Joint - surgery; Hip Prosthesis - adverse effects; Materials Testing; Prosthesis Failure; Sheep; Vitallium - adverse effects
• ISSN: 0954-4119
• DOI: 10.1243/09544119JEIM208

The degradation of Co-Cr-Mo ASTM F75-92 hip implants after a harvesting period of 81 months in sheep was investigated. Hip prostheses and tissue samples were obtained from a medical study involving total hip arthroplasty of the cemented type in 12 sheep. Upon euthanasia, the explants were retrieved for analyses of the surfaces and evidence of degradation, while tissue samples from the interface regions were harvested for chemical analysis and evidence of Co, Cr, and Mo contents. Clear evidence of wear and corrosion was detected. Results also indicated that the modes of metal transport through the poly(methyl methacrylate) bone cement play an important role as the surface degradation mechanisms of the metal. The results are being discussed in terms of electrochemical and triboelectrochemical behaviour of the Co-Cr-Mo alloy.