Title: Finite element modelling of lumbar motion segment using digitiser

Authors: Kim-Kheng Lee, Ee-Chon Teo, Tian-Xia Qiu, Hong-Wan Ng, Kai Yang

Addresses: School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, 639798, Singapore. ' School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, 639798, Singapore. ' School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, 639798, Singapore. ' School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, 639798, Singapore. ' School of Mechanical and Production Engineering, Nanyang Technological University, Nanyang Ave, 639798, Singapore

Abstract: In mathematical modelling of spine for biomechanical studies, researchers have always accentuated for accurate geometric, material and physical representation of the complex spinal components in order to have a better and deeper understanding of their functions and influences individually or holistically as well as improving accuracy of biomechanical responses. In this study, the methodology for the modelling of a detailed, three-dimensional, anatomically accurate finite element (FE) model of lumbar spine L2–L3 using a precise flexible digitiser to extract intricate geometrical details is presented to illustrate the feasibility of modelling technique in developing for volume mesh construction. Such acquisition method is different from commonly employed CT scan images. The anatomically accurate FE model consisted of 8581 eight-noded isoparametric solid element and 817 cable elements with 32,641 degrees of freedom. All complex anatomical features of the spine such as lamina, superior/inferior facet, pedicle, spinous process and transverse process were explicitly represented in this FE model. By incorporating geometrical and material nonlinearities into the model, the predicted results for compression, flexion, extension, lateral bending and torsion correlate well with experimental data under similar loading configurations. The results suggest that the direct digitisation provides another mean to accurately model such complex geometry with fine mesh representation for FE analysis, which is a vital requirement for study of gross responses under loadings as well as stress distribution for fracture analysis and bone remodelling.

Keywords: biomechanics; lumbar spine; finite element method; FEM; digitiser; modelling; simulation; spine loading; stress distribution.

DOI: 10.1504/IJCAT.2004.005335

International Journal of Computer Applications in Technology, 2004 Vol.21 No.1/2, pp.23 - 31

Published online: 25 Sep 2004 *

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