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An Anisotropic Porous Media Model of the Intervertebral Disc
Author(s) -
Karajan Nils,
Ehlers Wolfgang,
Markert Bernd
Publication year - 2003
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200310365
Subject(s) - annulus (botany) , microscale chemistry , orthotropic material , intervertebral disc , isotropy , anisotropy , poromechanics , materials science , nucleus , curvilinear coordinates , porous medium , mechanics , anatomy , physics , composite material , porosity , engineering , structural engineering , optics , biology , finite element method , mathematics , mathematics education , quantum mechanics , microbiology and biotechnology
Abstract On the microscale, the human intervertebral disc is a complex arrangement of mostly water, collagen (arranged in fibre bundles), proteoglycans and proteins. Attempting to separately describe each component would yield a too elaborated model, even by todays computing power. Therefore, an appropriate macro model needs to be developed. This can be done by splitting the disc into two distinct regions, which are a gelatinous core (nucleus pulposus) surrounded by a pliant, fibrous composite tissue (annulus .brosus). The nucleus may be considered as an isotropic material, whereas anisotropic effects have to be included for the annulus. This is due to the present fibres, which are not arranged in ideal chaos, but are assumed to be helically arranged yielding a locally orthotropic material.