Stress distribution in the knee joint in relation to tibiofemoral angle using the finite element method

Robert Karpiński,Łukasz Jaworski,Józef Jonak,Przemysław Krakowski,M Kulisz,W Cel,M Badurowicz,T Tulwin,M Szala,K Falkowicz,J Kujawska,Z Czyż,M Chmielewska

doi:10.1051/matecconf/201925207007

Abstract

The article presents the results of a preliminary study on the structural analysis of the knee joint, considering changes in the mechanical properties of the articular cartilage of the joint. Studies have been made due to the need to determine the tension distribution occurring in the cartilage of the human knee. This distribution could be the starting point for designing custom made human knee prosthesis. Basic anatomy, biomechanical analysis of the knee joint and articular cartilage was introduced. Based on a series of computed tomography [CT] scans, the 3D model of human knee joint was reverse-engineered, processed and exported to CAD software. The static mechanical analysis of the knee joint model was conducted using the finite element method [FEM], in three different values of tibiofemoral angle and with varying mechanical properties of the cartilage tissue. Main conclusions of the study are: the capability to absorb loads by articular cartilage of the knee joint is preliminary determined as decreasing with increasing degenerations of the cartilage and with age of a patient. Without further information on changes of cartilage’s mechanical parameters in time it is hard to determine the nature of relation between mentioned capability and these parameters.

Highlights

Osteoarthritis is one of the most common diseases diagnosed by general practitioners and orthopaedic surgeons [1]
Knee joint, which is the biggest joint in the human body is highly susceptible to osteoarthritic changes due to its location, function and mechanical properties
Research society is looking for possible ways to delay or even stop osteoarthritic changes

Summary

Introduction

Osteoarthritis is one of the most common diseases diagnosed by general practitioners and orthopaedic surgeons [1] It is a complex process, in which degeneration of articular cartilage, subchondral bone and synovium can be observed. Main symptoms of osteoarthritis include pain, stiffness of affected joint, which impair daily activities. Conditions such as obesity, joint overload, smoking, trauma or hormonal dysregulation have impact on onset of arthritic changes [4, 5]. Research society is looking for possible ways to delay or even stop osteoarthritic changes. For this purpose, a throughout recognition of each factor influencing gait and knee mechanics is crucial. Progress in the development of numerical methods used in medicine makes it possible to collect necessary data without the need of in vivo human joint testing [6,7,8,9,10]

Anatomy and biomechanics of knee joint

Methodology of the study

FEA method

Boundary conditions

Findings

Conclusion