ARUP; ISBN: 978-0-9562121-5-3 - CMBBE 2012 - Cardiff University

Parametric Study On The Effect Of Modelling Meniscal
Attachment
Carolina Dopico-Gonzalez, Sam Evans, Cathy Holt
Arthritis Research UK Biomehcanics and Bioengineerign Centre, (ARUK BBC), School of
|Engineering, Cardiff University, (Wales, UK)
Abstract
In the present work, a parametric study has been performed on a finite element model
of an intact knee, to compare the influence of different meniscal attachment on the
stresses and displacements of the different components of the knee. The bone models
were developed from MRI scans of a healthy volunteer, and the soft tissues (femoral
cartilage, ligaments and menisci) were idealised to approximate shapes and
attachments. The bones were modelled as rigid bodies, and the soft tissues were
modelled as linear isotropic materials, with parameters obtained from previous
studies. The menisco-tibial attachments were modelled in three different scenarios:
fully attached, partially attached under the horns and just attached at the tips of the
horns. The results showed that the increase of the sliding contact of the menisci with
the tibia produced a significant increase of stress and displacement of the menisci, a
significant increase of the femoral range of motion, and a significant decrease of the
ACL first principal stress.
1. Introduction
The knee joint is a very complex system composed of bones and many load bearing,
absorbing, and stabilising structures, such as ligaments, bone cartilage, menisci,
synovial fluid, joint capsule, etc [1]. In the knee joint, all the different structures
interact and influence each other, i.e., those which are in contact, such as femoral
cartilage with patellar cartilage, or femoral cartilage with menisci, and those which
are attached to each other, such as ligaments and bones, or menisci and tibial
cartilage. The menisci are crescent shaped fibrocartilagenous components that protect
the articular cartilage of the femoral condyles and tibial plateau during load
transmission through a number of roles. For years they were considered functionless
remains of leg muscles that, through evolution, had become intra-articular [2]. Later,
in 1932 [3], it was found that menisci have a crucial role in the formation of wedgeshaped
films of synovia, necessary for load transmission in the knee. In 1936 [4], a
study also suggested that the menisci act as shock absorbers to protect the femoral and
tibial articular cartilages. More recently, in 2006 [5], it has been suggested that the
menisci have a proprioceptive role and aid in the nutrition of the articular cartilage.
Other evidences of the weight-bearing function of the menisci are found on studies on
menisectomies [6-9]. Some studies have suggested a relation between menisectomy
and the development of osteoarthritis [10,11]. In the present study, the aim was to
investigate the effects of the variation on the menisco-tibial attachments. The
menisco-tibial contact is particularly complex, there are several ligaments that link the
menisci between them and with the tibia, and there are studies that have shown some
degree of motion of the menisci [12-14]. These studies show evidence of the influence
that meniscal mobility has on stabilising the knee.
The most recent FE models of the intact knee have considered the horn attachments of
the menisci through a few ligaments to the tibia [16-18]. The object of this study is to