Design of the guideline of the prevention of ion release from the frictional surface with the micro motion in a joint prosthesis by the clarification of fretting corrosion mechanism.

2016 Fiscal Year Final Research Report

• Project/Area Number: 26420083
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Design engineering/Machine functional elements/Tribology
• Research Institution: Kitasato University
• Principal Investigator: Kyoshi Mabuchi 北里大学, 医療衛生学部, 名誉教授 (70118842)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 人工股関節 / 微動摩耗 / 不動態被膜 / 摩耗試験 / 腐食電位 / 摩擦ストローク

Outline of Final Research Achievements

A hip prosthesis is designed to be modular, so that there is an interface of two solids where they contact, e.g., the bearing surface consists of a liner and the femoral head or the taper junction between a femoral stem and a head ball. Recently, it has been reported that release of metal ions from these interfaces caused the serious adverse reactions in the patients' body. The main mechanism was supposed the fretting corrosion. The present study aimed to investigate the effects of friction stroke length under reciprocating motion on damage and restoration of the passive film on the interface of contacting flat surfaces of CoCr alloy.
As the results of electrical sensing of ion release from the metal surfaces, friction with short strokes can cause damage to the passive film with plastic deformation. Friction with long stroke shortens the restoration time because of mechanical activation of the surface.

Free Research Field

医用機械工学