Transient mixed lubrication model of the human knee implant. Issue 4 (22nd August 2021)

• Record Type: Journal Article
• Authors: Butt, Hamza; Nissim, Lee; Gao, Leiming; Myant, Connor; de Boer, Greg; Hewson, Robert
• Is Part Of: Biosurface and biotribology. Volume 7:Issue 4(2021)
• Page Start: 206
• Page End: 218
• Publication Date: 2021-08-22
• Subjects: complex geometry -- knee implant -- mixed lubrication modelling -- surface roughness -- transient; Tribology -- Periodicals; Biomedical materials -- Periodicals; Tribology -- Congresses -- Periodicals; Biomedical materials -- Congresses -- Periodicals; Biological interfaces -- Congresses -- Periodicals; Biological interfaces; Biomedical materials; Tribology; Biocompatible Materials; Surface Properties; Materials Testing; Periodicals; Electronic journals; Periodical; Electronic journals; 610.28
• DOI: 10.1049/bsb2.12020
• Languages: English
• ISSNs: 2405-4518

Abstract

Abstract: The human knee implant is computationally modelled in the mixed lubrication regime to investigate the tribological performance of the implant. This model includes the complex geometry of the implant components, unlike elliptical contact models that approximate this geometry. Film thickness and pressure results are presented for an ISO gait cycle to determine the lubrication regime present within the implant during its operation. It was found that it was possible for the lubrication regime to span between elastohydrodynamic, mixed and boundary lubrication depending on the operating conditions of the implant. It was observed that the tribological conditions present in one condyle were not necessarily representative of the other. Multiple points of contact were found within the same condyle, which cannot be computed by the elliptical contact solvers. This model can be used to balance forces in all directions, instead of only the normal loads, as often done in elliptical contact models. This work is an initial step towards understanding the role of the complex geometry in the tribological characteristics of the human knee implant when operating in physiological conditions.