A Three Dimensional Finite Element Analysis of The Osteoporotic Lumbar Spine

• Main Authors: Chen, Shou-I, 陳守義
• Other Authors: Chang Chih-Han
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/92736104529604678837

碩士 === 國立成功大學 === 醫學工程研究所 === 86 === The objective of this study is to establish a three dimensional finite element spine mesh model with more realistic approximation in the geometry and material property distribution of human spine. This model is employed for osteoporosis analysis to investigate the basic mechanism in spine fracture. For compression loading in normal spine, due to the cancellous bone strength was far weaker than cortical shell, end-plate would deform into a concave shape in the center region. The end-plate then distributed the loading to the cortical shell and resulted in a bending effect on cortical shell which generated the tension stresses in the anterior superior region of the cortical shell. In the simulation of osteoporotic spine, when the strength of the cortical shell reduced up to 75% (accompany with cancellous bone lose) this would enhanced superior tension stress of cortical shell and probably causing the anterior wedge fracture of the spine. When the cortical shell vanished (cortical shell strength reduced up to 99%), the stresses of the cancellous bone increased dramatically which might be the reason of the crush fracture of the spine. When the strength of cancellous bone decreased more than cortical shell, the end- plate concave deformation become more serious, which resulted in bioconcave fracture of the spine. Considering the flexion loading condition, the stresses pattern of normal spine model was altered into a more crucial case, and this phenomenon was more sensitive in osteoporotic model which will increase the probability of osteoporotic fracture.