Computational study on lateral and medial wear characterization in knee implants by a multibody dynamic system

G Fekete

doi:10.1007/s00707-020-02868-4

G Fekete

Open Access

https://doi.org/10.1007/s00707-020-02868-4

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Journal: Acta Mechanica	Publication Date: Jan 8, 2021
Citations: 4	License type: open-access

Affiliation: Eötvös Loránd University, Ningbo University

Abstract

Wear is one of the main mechanical factors that limits the survival of total knee replacements (TKRs) and it is known to be highly dependent on the local kinematics of the knee joint. In this study, an analytical wear model was coupled to a multibody dynamic model to obtain wear distribution at the lateral and medial contact plateaus of different TKRs. The major aim was to analyze if wear distribution on the contact plateaus can be an indicator of elevated tibiofemoral misalignment which can lead to rapid TKR failure. For the multibody dynamic simulations, commercial and prototype TKR geometries were used, coupled with an augmented Archard’s law. Squat movement was chosen due to its importance both in sports and in everyday life. As a conclusion, a new parameter, denoted as wear imbalance, is introduced, which can indicate whether a TKR, due to its geometrical features, is prone to be subjected to elevated wear and failure.

Highlights

Due to the constant development of total knee replacements (TKRs), their reliability continuously improves, but failures still occur
In order to better qualify the eventual differences between the investigated TKRs, a quantitative comparison has been made with regard to total wear propagation (Fig. 7)
It was apparent from the results that this TKR provided the lowest total wear and the most balanced wear propagation among the other TKRs

Summary

Introduction

Due to the constant development of total knee replacements (TKRs), their reliability continuously improves, but failures still occur. The most influencing and researched direct wear-inducing parameters are the load and the sliding-velocity (or path), serious emphasis is paid to the slide-roll ratio as well. This ratio is often considered constant, based on the study of McGloughlin and Kavanagh [2], and it has been frequently considered and applied on pin-on-disc test rigs or knee simulators [3,4,5]. One common (TW = total wear per million cycle) and three new wear parameters are introduced to characterize TKR wear: the relative lateral and relative medial wear (RWlateral, RWmedial), and most importantly, the wear imbalance (WIB).

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Discussion

Conclusion