Stress Changes in Intervertebral Discs of the Cervical Spine After Arthrodesis

2002 ◽  
Author(s):  
Abraham Tchako ◽  
Ali Sadegh
Keyword(s):  
Cervical Spine ◽  
Intervertebral Discs ◽  
Measurement Tool ◽  
Fe Model ◽  
Lower Cervical Spine ◽  
Stress Changes ◽  
Spine Model ◽  
Vertebral Bodies ◽  
Cervical Spine Fusion ◽  
Geometric Measurement

An improved and detailed 3D FE model of human cervical spine model was created using digitized geometric measurement tool. The vertebral bodies of the model were fused at three locations. The unfused and the fused models were physiologically loaded and the changes in stresses in intervertebral discs were compared. A moment of 1.5 Nm was used in combination with a 50 N compressive preload. The results showed that the lower cervical spine fusion induces the most stress changes in the neighboring discs.

Stress Changes in Intervertebral Discs of the Cervical Spine After Partial Fusion

2003 ◽  
Author(s):  
Abraham Tchako ◽  
Ali M. Sadegh
Keyword(s):  
Cervical Spine ◽  
Axial Rotation ◽  
Intervertebral Discs ◽  
Fe Model ◽  
Loading Mode ◽  
Flexion Extension ◽  
Stress Changes ◽  
Partial Fusion ◽  
The Difference ◽  
Disc Level

A detailed and validated 3D FE model of human cervical spine (Sadegh et al. 2000) was altered to simulate partial fusion. Five single level partially fused new models, one at each disc level, were used to study the change in stresses in adjacent levels. Two cases of partial fusion, 80% and 60% were considered. The fused models were loaded with a 50 N compressive pre-load and with a 1.5 Nm moment in flexion, extension, lateral bending and axial rotation. The previously obtained results of the unfused model (Tchako et al. 2002) and of the fused models were used to study the change in stresses in adjacent levels. The results indicate that, in general, there are stress changes as high as 94%, depending on the loading mode and location, in adjacent discs after discectomy and fusion. However, the difference between the stress change of 80% and 60% of partial fusion is insignificant.

scholarly journals A comparative shape analysis of the cervical spine between individuals with cervicogenic headaches and asymptomatic controls

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Youssef Masharawi ◽  
Aumayma Murad Mansour ◽  
Natan Peled ◽  
Asaf Weisman
Keyword(s):  
Cervical Spine ◽  
Cervical Vertebrae ◽  
Cervicogenic Headache ◽  
Intervertebral Discs ◽  
Shape Variation ◽  
Control Groups ◽  
Transverse Foramen ◽  
Cervicogenic Headaches ◽  
Vertebral Bodies ◽  
And Control

AbstractAs some researchers theorized that cervicogenic headache (CEH) might be related to bony and discal features of the cervical spine, this retrospective study examined the shapes of the cervical vertebrae and intervertebral discs (IVDs) of individuals with CEH and compared them to asymptomatic controls. Scans of 40 subjects in their late 20’s–mid 30’s affected with CEH and 40 asymptomatic controls were obtained (overall = 19,040 measurements, age-sex matched, 20 males and 20 females in each group). The following cervical spine variables were measured: Supine lordosis, vertebral body-heights, A-P lengths, mediolateral widths and sagittal-wedging; IVDs heights and sagittal-wedging; pedicle heights, widths and transverse angles; laminar widths and transverse angles; articular facet angles, spinal canal, and transverse foramen lengths, widths, and areas. Both groups had similar shape variation along the cervical in all the measured parameters. There were no significant left–right differences in all measured parameters and no significant differences between the CEH and control groups concerning sex and age. Cervical IVDs were lordotic in shape, whereas their adjacent vertebral bodies were kyphotic in shape except for C2. In conclusion, the shape of the cervical spine and IVDs in subjects in their late 20’s–mid 30’s affected with CEH is identical to asymptomatic controls.

Development and Validation of a Three-Dimensional Finite Element Model of Cervical Spine (C3-C5)

2010 ◽  
Author(s):  
N. Bahramshahi ◽  
H. Ghaemi ◽  
K. Behdinan
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Three Dimensional ◽  
Element Model ◽  
Intervertebral Discs ◽  
Fe Model ◽  
Two Phase ◽  
Finite Element Software ◽  
Flexion Extension ◽  
Disc Bulge

The objective of this investigation is to develop a detailed, non-linear asymmetric three-dimensional anatomically and mechanically accurate FE model of complete middle cervical spine (C3-C5) using Hypermesh and MSC.Marc software. To achieve this goal, the components of the cervical spine are modeled using 20-noded hexagonal elements. The model includes the intervertebral disc, cortical bone, cancellous bone, endplates, and ligaments. The structure and dimensions of each spinal component are compared with experimentally measured values. In addition, the soil mechanics formulation of MSC.Marc finite element software is applied to model the mechanical behaviour of vertebrae and intervertebral discs as linear isotropic two-phase (biphasic) material. The FE simulation is conducted to investigate compression, flexion\extension and right\Left lateral bending modes. The simulation results are validated and compared closely with the published experimental data and the existing FE models. In general, results show greater flexibility in flexion and less flexibility in extension. The flexion/extension curves are asymmetric with a greater magnitude in flexion than in extension. In addition, the variations of the predicted lateral C4-C5 disc bulge are investigated and the results show that the maximum disc bulge occurs at the C4-C5 anterior location.

scholarly journals A Constitutive Model for the Annulus of Human Intervertebral Disc: Implications for Developing a Degeneration Model and Its Influence on Lumbar Spine Functioning

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
J. Cegoñino ◽  
V. Moramarco ◽  
A. Calvo-Echenique ◽  
C. Pappalettere ◽  
A. Pérez del Palomar
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Porous Matrix ◽  
Intervertebral Discs ◽  
Nonlinear Material ◽  
Theoretical Modelling ◽  
Fe Model ◽  
Spine Model

The study of the mechanical properties of the annulus fibrosus of the intervertebral discs is significant to the study on the diseases of lumbar intervertebral discs in terms of both theoretical modelling and clinical application value. The annulus fibrosus tissue of the human intervertebral disc (IVD) has a very distinctive structure and behaviour. It consists of a solid porous matrix, saturated with water, which mainly contains proteoglycan and collagen fibres network. In this work a mathematical model for a fibred reinforced material including the osmotic pressure contribution was developed. This behaviour was implemented in a finite element (FE) model and numerical characterization and validation, based on experimental results, were carried out for the normal annulus tissue. The characterization of the model for a degenerated annulus was performed, and this was capable of reproducing the increase of stiffness and the reduction of its nonlinear material response and of its hydrophilic nature. Finally, this model was used to reproduce the degeneration of the L4L5 disc in a complete finite element lumbar spine model proving that a single level degeneration modifies the motion patterns and the loading of the segments above and below the degenerated disc.

scholarly journals Effect of Model Parameters on the Biomechanical Behavior of the Finite Element Cervical Spine Model

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Suzan Cansel Dogru ◽  
Yunus Ziya Arslan
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Elastic Modulus ◽  
Angular Motion ◽  
Model Parameters ◽  
Stress And Strain ◽  
Fe Model ◽  
Biomechanical Behavior ◽  
Spine Model ◽  
Strain Responses

Finite element (FE) models have frequently been used to analyze spine biomechanics. Material parameters assigned to FE spine models are generally uncertain, and their effect on the characterization of the spinal components is not clear. In this study, we aimed to analyze the effect of model parameters on the range of motion, stress, and strain responses of a FE cervical spine model. To do so, we created a computed tomography-based FE model that consisted of C2-C3 vertebrae, intervertebral disc, facet joints, and ligaments. A total of 32 FE analyses were carried out for two different elastic modulus equations and four different bone layer numbers under four different loading conditions. We evaluated the effects of elastic modulus equations and layer number on the biomechanical behavior of the FE spine model by taking the range of angular motion, stress, and strain responses into account. We found that the angular motions of the one- and two-layer models had a greater variation than those in the models with four and eight layers. The angular motions obtained for the four- and eight-layer models were almost the same, indicating that the use of a four-layer model would be sufficient to achieve a stress value converging to a certain level as the number of layers increases. We also observed that the equation proposed by Gupta and Dan (2004) agreed well with the experimental angular motion data. The outcomes of this study are expected to contribute to the determination of the model parameters used in FE spine models.

A Novel Anterior Transpedicular Screw Artificial Vertebral Body System for Lower Cervical Spine Fixation: A Finite Element Study

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Weidong Wu ◽  
Chun Chen ◽  
Jinpei Ning ◽  
Peidong Sun ◽  
Jinyuan Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Vertebral Body ◽  
Facet Joint ◽  
Lower Cervical Spine ◽  
Body System ◽  
Joint Force ◽  
Transpedicular Screw ◽  
Spine Model ◽  
Artificial Vertebral Body

A finite element model was used to compare the biomechanical properties of a novel anterior transpedicular screw artificial vertebral body system (AVBS) with a conventional anterior screw plate system (ASPS) for fixation in the lower cervical spine. A model of the intact cervical spine (C3–C7) was established. AVBS or ASPS constructs were implanted between C4 and C6. The models were loaded in three-dimensional (3D) motion. The Von Mises stress distribution in the internal fixators was evaluated, as well as the range of motion (ROM) and facet joint force. The models were generated and analyzed by mimics, geomagic studio, and ansys software. The intact model of the lower cervical spine consisted of 286,382 elements. The model was validated against previously reported cadaveric experimental data. In the ASPS model, stress was concentrated at the connection between the screw and plate and the connection between the titanium mesh and adjacent vertebral body. In the AVBS model, stress was evenly distributed. Compared to the intact cervical spine model, the ROM of the whole specimen after fixation with both constructs is decreased by approximately 3 deg. ROM of adjacent segments is increased by approximately 5 deg. Facet joint force of the ASPS and AVBS models was higher than those of the intact cervical spine model, especially in extension and lateral bending. AVBS fixation represents a novel reconstruction approach for the lower cervical spine. AVBS provides better stability and lower risk for internal fixator failure compared with traditional ASPS fixation.

scholarly journals Tomodensitometric Bone Anatomy of The Intervertebral Foramen of The Lower Cervical Spine: Measurements and Comparison of Foraminal Volume in Healthy Individuals and Patients Suffering from Cervicobrachial Neuralgia Due to Foraminal Stenosis.

2022 ◽  
Author(s):  
Pierre COUDERT ◽  
Gaetan LAINE ◽  
Vincent POINTILLART ◽  
Camille DAMADE ◽  
Louis BOISSIERE ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Current Knowledge ◽  
Intervertebral Discs ◽  
Lateral Part ◽  
Foraminal Stenosis ◽  
Medial Part ◽  
Lower Cervical Spine ◽  
Intervertebral Foramen ◽  
Asymptomatic Group ◽  
Symptomatic Group

Abstract Purpose Degenerative foraminal stenosis of the cervical spine can lead to cervicobrachial neuralgias. Computed tomography (CT)-scan assists in the diagnosis and evaluation of foraminal stenosis. The main objective of this study is to determine the bony dimensions of the cervical intervertebral foramen and to identify which foraminal measurements are most affected by degenerative disorders of the cervical spine. These data could be applied to the surgical treatment of this pathology, helping surgeons to focus on specific areas during decompression procedures. Methods A descriptive study was conducted between two groups: an asymptomatic one (young people with no evidence of degenerative cervical spine disorders) and a symptomatic one (experiencing cervicobrachial neuralgia due to degenerative foraminal stenosis). Using CT scans, we determined a method allowing measurements of the following foraminal dimensions: foraminal height (FH), foraminal length (FL), foraminal width in its lateral part ((UWPP, MWPP and IWPP (respectively Upper, Medial and Inferior Width of Pedicle Part)) and medial part (UWMP, MWMP and IWMP (respectively Upper, Medial and Inferior Width of Medial Part)), and disk height (DH). Foraminal volume (FV) was calculated considering the above data. Mean volumes were measured in the asymptomatic group and compared to the values obtained in the symptomatic group. Results Both groups were made up of 10 patients, and a total of 50 intervertebral discs (100 intervertebral foramina) were analyzed in each group. Comparison of C4C5, C5C6 and C6C7 levels between both groups showed several significant decreases in foraminal dimensions (p< 0,05) as well as in foraminal volume (p <0.001) in the symptomatic group. The most affected dimensions were UWPP, MWPP, UWMP, MWMP and FV. The most stenotic foraminal areas were the top of the uncus and the posterior edge of the lower plate of the overlying vertebra. Conclusion Using a new protocol for measuring foraminal volume, the present study refines the current knowledge of the normal and pathological anatomy of the lower cervical spine and allows us to understand the foraminal sites most affected by degenerative stenosis. Those findings can be applied to foraminal stenosis surgeries. According to our results, decompression of the foramen in regard of both uncus osteophytic spurs and inferior plate of the overlying vertebra might be an important step for nerve roots release.

Management of The Cervical Spine Tuberculosis

2018 ◽  
Vol 1 (2) ◽  
pp. 19
Author(s):  
Sabri Ibrahim
Keyword(s):  
Magnetic Resonance Imaging ◽  
Cervical Spine ◽  
Magnetic Resonance ◽  
Spinal Tuberculosis ◽  
Intervertebral Disk ◽  
Posterior Fixation ◽  
Resonance Imaging ◽  
Vertebral Bodies ◽  
Intervertebral Disk Space ◽  
Developed Nations

Tuberculosis of the cervical spine is a rare clinical condition (10%), most commonly affected lower thoracic region (40-50% of the cases). Spinal tuberculosis is a destructive form of tuberculosis. It accounts for approximately half of all cases of musculoskeletal tuberculosis. Spinal tuberculosis is more common in children and young adults. The incidence of spinal tuberculosis is increasing in developed nations. Characteristically, there is a destruction of the intervertebral disk space and the adjacent vertebral bodies, collapse of the spinal elements, and anterior wedging leading to kyphosis and gibbus formation. For the diagnosis of spinal tuberculosis, magnetic resonance imaging is more sensitive than x-ray and more specific than computed tomography. Magnetic resonance imaging frequently demonstrates an involvement of the vertebral bodies on either side of the disk, disk destruction, cold abscess, vertebral collapse, and presence of vertebral column deformities. Anti-tuberculous treatment remains the cornerstone of treatment. Surgery may be required in selected cases, e.g. large abscess formation, severe kyphosis, an evolving neurological deficit, or lack of response to medical treatment. The quality of debridement and bony fusion is optimal when the anterior approach is used. Posterior fixation is the best means of achieving reduction followed by stable sagittal alignment over time. With early diagnosis and early treatment, the prognosis is generally good.

Sign in / Sign up

Export Citation Format

Share Document