Skip to Main content Skip to Navigation
Theses

Modélisation de la liaison os-ligament dans l'articulation du genou

Abstract : This PhD thesis is devoted to the improvement of the knowledge of the soft tissues mechanical behaviour, particularly in the field of accidentology. This study aims at linking the concepts of injury used for clinical diagnostic and these of damage and failure used in mechanics. It deals with the modeling of the ligaments behaviour in the knee joint, and the role played by ligament-to-bone insertion in particular. This structure, composed of the ligament and the insertion sites, is injured either in the ligament itself (in the midsubstance) or near the ligament-to-bone transition. This problem is original according to anatomical and mechanical points of view. Anatomically there is no precise description at the microscopic level of the architecture of this transition, that seems to be very sharp at the macroscopic level, whereas it is a possible place of injury. Mechanically, it is the study of a biological tissue that is besides the transition from a mineralised hard tissue (the bone) to a non mineralised soft tissue composed of long fibres (the ligament). The methodology developed here was: understanding how the knee joint works and which injuries and traumatims occur in this joint, determining what the transition is composed of and how its components are organised, by performing a histological study, describing its mechanical behaviour and its contribution to the global behaviour of the knee, by developing an experimental protocol, and, lastly, developing a model of the mechanical behaviour of the ligament-to-bone transition. This study is devoted to the posterior cruciate and lateral collateral ligaments, the injury mechanisms of which, in the case of road accidents, were more specifically studied. The architecture of the ligament-to-bone transition was described thanks to light and electron microscopies: it is the superimposition of a mineralisation front and structural changes in the tissue (there is fibrocartilage). This transition is about 300 micrometres. The experimental tensile tests were performed on the ligament insertion - ligament - ligament insertion structure cut off from post mortem human subjects (PMHS). The structure was subjected to tensile load, either along the fiber direction, or in a realistic direction according to anatomical considerations (physiological configuration). The protocols developed in this thesis enable to perform non destructive cyclic tests, and failure tests, under quasi - static (1 mm/s and 20 mm/s) and dynamic (0.5 m/s and 1 m/s) loadings. For the physiological configuration, knees were tested with an angle of knee flexion of 180 degres (standing position) and 120 degres (driving position). The experimental results show that the ligaments dissipate energy during cyclic loading because of internal friction, and that their behaviours highly depend on the angle of knee flexion, at least in the loading range tested. Under quasi-static conditions, failure always occurs by avulsion in the cortical bone. Under dynamic conditions, in the loading range tested, there is firstly loss of cohesiveness between ligament fibres, but failure occurs most often because of deep alvusion of trabecular bone. Considering that the ligament mechanical behaviour depends on the orientation of the insertion sites, and knowing the microstructure of the insertion site, we chose an interface model to describe its behaviour. Two models of cohesive zones (coupling friction, adhesiveness, and damage) were developed to predict ligament injuries due to bone avulsion and loss of cohesiveness between ligament fibres.
Complete list of metadatas

Cited literature [73 references]  Display  Hide  Download

https://tel.archives-ouvertes.fr/tel-00008443
Contributor : Damien Subit <>
Submitted on : Wednesday, February 16, 2005 - 4:13:57 AM
Last modification on : Tuesday, December 8, 2020 - 10:20:50 AM
Long-term archiving on: : Friday, September 14, 2012 - 11:10:09 AM

Identifiers

  • HAL Id : tel-00008443, version 1

Collections

Citation

Damien Subit. Modélisation de la liaison os-ligament dans l'articulation du genou. Mécanique [physics.med-ph]. Université de la Méditerranée - Aix-Marseille II, 2004. Français. ⟨tel-00008443⟩

Share

Metrics

Record views

1190

Files downloads

6092