scholarly journals Establishment and Finite Element Analysis of a Three‐dimensional Dynamic Model of Upper Cervical Spine Instability

2019 ◽  
Vol 11 (3) ◽  
pp. 500-509 ◽  
Author(s):  
Xiao‐dong Wang ◽  
Min‐shan Feng ◽  
Yong‐cheng Hu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cervical Spine ◽  
Dynamic Model ◽  
Three Dimensional ◽  
Upper Cervical Spine ◽  
Cervical Spine Instability ◽  
Element Analysis ◽  
Upper Cervical

Moment Prediction for Evaluating Stability of the Upper Cervical Spine Fixed with Wires Using Finite Element Analysis

2006 ◽  
Vol 321-323 ◽  
pp. 1098-1102
Author(s):  
Hyo Shin Kim ◽  
Youn Soo Kim ◽  
Joung H. Mun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cervical Spine ◽  
High Rate ◽  
Posterior Fixation ◽  
Upper Cervical Spine ◽  
Element Analysis ◽  
Surgical Methods ◽  
Upper Cervical ◽  
The Moment

This study was aimed at predicting moments with respect to diameters of wires for evaluating stability of the upper cervical spine fixed with wires based on the finite element analysis. In case of the severe atlanto-axial instability, several surgical methods have been tried and the posterior fixation using wires has been widely used because of the sufficient stability and high rate of bony adhesion. The diameters of wires applied in this study were 0.7 mm, 0.9 mm and 1.25 mm. 1.5 Nm is the moment for the normal physiological range of motion of the upper cervical spine in cadaver models. However, if this moment is applied to the occiput, an excessive load occurs at the occipito-atlantal joint and clinical problems can break out realistically. Thus, it is necessary to predict moments for evaluating stability with respect to diameters of wires. The results showed that 0.7 mm wire allowed the biggest moment while 1.25 mm wire allowed the smallest moment. In addition, the upper cervical spine fused with wires was stabilized effectively as the load increased.

Investigation of Upper Cervical Spine Injury due to Frontal and Rear Impact Loading Using Finite Element Analysis

2014 ◽  
Author(s):  
Tanvir Mustafy ◽  
Kodjo Moglo ◽  
Samer Adeeb ◽  
Marwan El-Rich
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Motor Vehicle ◽  
Spine Injury ◽  
Upper Cervical Spine ◽  
Fe Model ◽  
Facet Joints ◽  
Element Analysis ◽  
Effective Prevention ◽  
Upper Cervical

Predicting neck response and injury resulting from motor vehicle crashes is essential for improving occupant protection, effective prevention, and in the evaluation and treatment of spinal injuries. Injury mechanism of upper cervical spine due to frontal/rear-end impacts was studied using Finite Element (FE) analyses. A FE model of ligamentous (devoid of muscles) occipito-C3 cervical spine was developed. Time and rate-dependent material laws were used for assessing bone and ligament failure. Frontal and rear-end impact loads at two rates of 5G and 10G accelerations were applied to analyze the model response in terms of stress distribution, intradiscal pressure change, and contact pressure in facet joints. Failure occurrence and initiation instants were investigated. Frontal and rear-end impacts increased stresses significantly producing failure in most components for both rates. However, transverse ligament and C2-vertebral endplate only failed under rear-end impact. No failure occurred in cortical bone, dens, disc, anterior or posterior longitudinal ligaments. The spine is more prone to injury under rear-end impact as most of the spinal components failed and failure started earlier. Ligaments and facet joints are the most vulnerable components of the upper cervical spine when subjected to frontal/rear end impacts and injury may occur at small ranges of displacement/rotation.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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