Effect of Asymmetry on Finite Element Model of Cervical Spine

Author(s):  
Iman Zafarparandeh ◽  
Deniz Erbulut ◽  
Ismail Lazoglu ◽  
Fahir Ozer

The cervical region of spinal column has been known as a frequent site of injuries. The major causes of injuries are vehicle accidents and sports. Clinical instability is known as one of the important topics in cervical spine research. It clarifies the relation between the mechanical dysfunction of the spine and the neurologic dysfunction and pain. From the clinical point of view, if the spinal segment exhibits abnormal large increase in rotational or translational displacements under physiological load, it is considered as unstable. There are different biomechanical models available to understand the underlying mechanisms of injury and dysfunction. Finite element (FE) models have been used as a strong tool to provide the basic insights into the workings of the cervical spine system. Furthermore, they have been clinically useful in the development of the definition of clinical instability and of diagnostic guidelines [1].

2021 ◽  
Author(s):  
Noushin Bahramshahi

The spinal cord may be injured through various spinal column injury patterns. However, the relationship between column injury pattern and cord damage is not well understood. This investigation was conducted to develop a detailed, asymmetric three-dimensional finite element model of the C3-C5 cervical spine. The model was validated by comparing the simulation results obtained in this study with experimental published data. Upon validation of the model, the spinal cord was included into the model the simulation were performed. The disc bulge in the model with spinal cord were measured and compared with the results of the model without spinal cord. The results showed that inclusion of the spinal cord reduced the amount of lateral disc bulged. The results of the analysis of the model with spinal cord showed that in compression, the anterior surface of spinal cord sees more displacement, stress and strain that posterior surface and vice versa for flexion/extension.


2021 ◽  
Author(s):  
Noushin Bahramshahi

The spinal cord may be injured through various spinal column injury patterns. However, the relationship between column injury pattern and cord damage is not well understood. This investigation was conducted to develop a detailed, asymmetric three-dimensional finite element model of the C3-C5 cervical spine. The model was validated by comparing the simulation results obtained in this study with experimental published data. Upon validation of the model, the spinal cord was included into the model the simulation were performed. The disc bulge in the model with spinal cord were measured and compared with the results of the model without spinal cord. The results showed that inclusion of the spinal cord reduced the amount of lateral disc bulged. The results of the analysis of the model with spinal cord showed that in compression, the anterior surface of spinal cord sees more displacement, stress and strain that posterior surface and vice versa for flexion/extension.


2011 ◽  
Vol 467-469 ◽  
pp. 339-344
Author(s):  
Na Li ◽  
Jian Xin Liu

Head and neck injuries are the most frequent severe injury resulting from traffic accidents. Neck injury mechanisms are difficult to study experimentally due to the variety of impact conditions involved, as well as ethical issues, such as the use of human cadavers and animals. Finite element analysis is a comprehensive computer aided mathematical method through which human head and neck impact tolerance can be investigated. Detailed cervical spine models are necessary to better understand cervical spine response to loading, improve our understanding of injury mechanisms, and specifically for predicting occupant response and injury in auto crash scenarios. The focus of this study was to develop a C1–C2 finite element model with optimized mechanical parameter. The most advanced material data available were then incorporated using appropriate nonlinear constitutive models to provide accurate predictions of response at physiological levels of loading. This optimization method was the first utilized in biomechanics understanding, the C1–C2 model forms the basis for the development of a full cervical spine model. Future studies will focus on tissue-level injury prediction and dynamic response.


Author(s):  
Sean M. Finley ◽  
J. Harley Astin ◽  
Evan Joyce ◽  
Andrew T. Dailey ◽  
Douglas L. Brockmeyer ◽  
...  

OBJECTIVE The underlying biomechanical differences between the pediatric and adult cervical spine are incompletely understood. Computational spine modeling can address that knowledge gap. Using a computational method known as finite element modeling, the authors describe the creation and evaluation of a complete pediatric cervical spine model. METHODS Using a thin-slice CT scan of the cervical spine from a 5-year-old boy, a 3D model was created for finite element analysis. The material properties and boundary and loading conditions were created and model analysis performed using open-source software. Because the precise material properties of the pediatric cervical spine are not known, a published parametric approach of scaling adult properties by 50%, 25%, and 10% was used. Each scaled finite element model (FEM) underwent two types of simulations for pediatric cadaver testing (axial tension and cardinal ranges of motion [ROMs]) to assess axial stiffness, ROM, and facet joint force (FJF). The authors evaluated the axial stiffness and flexion-extension ROM predicted by the model using previously published experimental measurements obtained from pediatric cadaveric tissues. RESULTS In the axial tension simulation, the model with 50% adult ligamentous and annulus material properties predicted an axial stiffness of 49 N/mm, which corresponded with previously published data from similarly aged cadavers (46.1 ± 9.6 N/mm). In the flexion-extension simulation, the same 50% model predicted an ROM that was within the range of the similarly aged cohort of cadavers. The subaxial FJFs predicted by the model in extension, lateral bending, and axial rotation were in the range of 1–4 N and, as expected, tended to increase as the ligament and disc material properties decreased. CONCLUSIONS A pediatric cervical spine FEM was created that accurately predicts axial tension and flexion-extension ROM when ligamentous and annulus material properties are reduced to 50% of published adult properties. This model shows promise for use in surgical simulation procedures and as a normal comparison for disease-specific FEMs.


1999 ◽  
Author(s):  
Chih-Han Chang ◽  
Chun-Li Lin ◽  
Chau-Hsiang Wang ◽  
Huey-Er Lee

Abstract The concept of stress-induced cervical lesions has been discussed widely in recent years. In this study, a three-dimensional finite element model was established to analyze the stress distribution at cervical region and evaluate the stresses on the interface of different restorative materials. The results indicated that tensile stress might be the major cause for tooth cervical lesion. For different restorative materials, the elastic modulus was not the key issue in premature loss of restorative material. The bonding strength between the restorative material and lesions could be the important factor for the retention failure.


2013 ◽  
Vol 273 ◽  
pp. 588-592
Author(s):  
Zhi Yuan Yan ◽  
Dong Mei Wu ◽  
Li Tao Zhang ◽  
Jun Zhao

In order to obtain high-quality analytical results of the finite element model, it is essential to construct a three dimensional geometric model. The paper reconstructed an accurate three dimensional geometric model of cervical spine segments (C4-C7). The process of reconstruction included three-dimensional reconstruction, smooth processing, contour generation, grid generation and fitting surface. Moreover, the result of reconstruction was evaluated ultimately. The model was validated to be smooth and reasonable, and could meet the requirements of finite element analysis. The method is not merely applied to reconstruct the geometric model of the cervical spine. It is a way to construct the model of the skeletal system of the human body.


2017 ◽  
Vol 17 (11) ◽  
pp. 1755-1764 ◽  
Author(s):  
Timothy L. Lasswell ◽  
Duane S. Cronin ◽  
John B. Medley ◽  
Parham Rasoulinejad

2018 ◽  
Vol 90 (4) ◽  
pp. 652-658
Author(s):  
Péter Deák

Purpose The purpose of this paper is to make an analytical comparison of two vertical tail models from a structural point of view. Design/methodology/approach The original vertical tail design of PZL-106BT aircraft was used for Computer aided design (CAD) modeling and for creating the finite element model. Findings The nodal displacements, Von-Mises stresses and Buckling factors for two vertical tail models have been found using the finite element method. The idea of a possible Multidisciplinary concept assessment and design (MDCAD) concept was presented. Practical implications The used software analogy introduces an idea of having an automated calculation procedure within the framework of MDCAD. Originality/value The aircraft used for calculation had undergone a modification in its vertical tail length, as there was an urgent need to calculate for the plane’s manufacturer, PZL Warszawa – Okecie.


Sign in / Sign up

Export Citation Format

Share Document