Finite element based simulation of tribocorrosion at the head-neck junction of hip implants. (January 2022)

• Record Type: Journal Article
• Authors: Fallahnezhad, Khosro; Feyzi, Mohsen; Ghadirinejad, Khashayar; Hashemi, Reza; Taylor, Mark
• Is Part Of: Tribology international. Volume 165(2022)
• Publication Date: 2022-01
• Subjects: Tribocorrosion -- Finite element modelling -- Taperosis -- Hip implants; Tribology -- Periodicals; 621.89
• DOI: 10.1016/j.triboint.2021.107284
• Languages: English
• ISSNs: 0301-679X

Abstract

Abstract: This study proposes a new finite element (FE) model for tribocorrosion at the head-neck junction of hip implants (known as taperosis). The model addresses the synergy in tribocorrosion to separate the role played by both the mechanical and chemical mechanisms. This algorithm was conceptualised for a ball-on-disk configuration; and it was then implemented on a distal fitting taper junction. Contact parameters and wear depths (both mechanical and chemical) were obtained as a result of level gait loading. The results demonstrate a linear pattern for the wear depths versus the number of loading cycles. The chemical wear spread over a larger area of the taper compared to the narrow region for the mechanical and total wear. Chemical reactions (corrosion) were responsible for 32% of the material loss; and this challenges the widely accepted assumption of neglecting the chemical wear in taperosis. The FE-predicted wear patterns were comparable with those observed in a number of retrieved tapers. Highlights: A novel FE model was developed for a ball-on-disk configuration with the capability of capturing the mechano-electrochemical nature of tribocorrosion. This model was well verified by a set of experimental results. The model was applied to a distally contacting head-neck junction to simulate taperosis. Chemical reactions were responsible for 32% of the material loss. Contact pressures decreased from 400 MPa to 25 MPa over 4 million cycles.