A BIOMECHANICAL STUDY OF THE EFFECTS OF FLEXION ANGLE ON THE INDUCTION MECHANISM OF CERVICAL SPONDYLOSIS

2021 ◽  
pp. 2150053
Author(s):  
FU CAO ◽  
RONGCHANG FU ◽  
WENYUAN WANG
Keyword(s):  
Cervical Spine ◽  
Cervical Spondylosis ◽  
Element Model ◽  
Intervertebral Discs ◽  
Biomechanical Study ◽  
Flexion Angle ◽  
Facet Joints ◽  
Load Increase ◽  
Spine Motion ◽  
Wolff’S Law

Lesions in facet joints such as bone hyperplasia and degenerative changes in the intervertebral discs, can compress nerve roots and the spinal cord, leading to cervical spondylosis (CS). Lesions in these parts of the spine are commonly related to abnormal loads caused by bad posture of the cervical spine. This study aimed to understand the potential mechanical effects of load amplitude on cervical spine motion to provide a theoretical basis for the biomechanical causes of CS, and to provide a reference for preventing of the condition. In this study, a finite element model of the normal human cervical spine (C1-C7) was established and validated using an infrared motion capture system to analyze the effects of flexion angle on the stresses experienced by intervertebral discs, the anterior edge of the vertebral body, the pedicle, uncinate and facet joints. Our analysis indicated that the intervertebral disc load increased by at least 70% during the 20∘ to 45∘ flexion of the neck with 121% load increase in the vertebrae. In the intervertebral discs, the stress was largest at C4-C5, and the stress was moderate at C5-C6. These results are consistent with clinical CS prone site research. According to Wolff’s law, when bones are placed under large stresses, hyperplasia can result to allow adaptation to large loads. Increased cervical spine flexion angles caused the proliferation of bone in the above-mentioned parts of the spine and can accelerate accelerating the appearance of CS.

scholarly journals A Review on Diagnosis and Management of Cervical Spondylosis

2021 ◽  
pp. 668-674
Author(s):  
Ahmed Abdulaziz G. Ibrahim ◽  
Ali Mohammed A. Alahmari ◽  
Abdullah Hassan F. Alsuayri ◽  
Abdullah Misfer M. Algomshah ◽  
Saeed Ghanem S. Almlfi ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Neck Pain ◽  
Cervical Spondylosis ◽  
Natural Aging ◽  
Posterior Longitudinal Ligament ◽  
Cervical Radiculopathy ◽  
Intervertebral Discs ◽  
Degenerative Changes ◽  
Facet Joints ◽  
Wide Range

Cervical spondylosis is a term that encompasses a wide range of progressive degenerative changes that affect all components of the cervical spine (i.e., intervertebral discs, facet joints, Luschka joints, flava ligaments, and laminae). It is a natural aging process and occurs in most people after the age of five. Most people with radiographic spondylotic changes in the cervical spine  remain asymptomatic, and 25% of those under  40, 50% of those over  40, and 85% of those over  60 show some evidence of degenerative changes , including changes in  the environment. Uncovertebral joints, facet joints, posterior longitudinal ligament (PLL) and yellow ligament lead to  narrowing of the spinal canal and intervertebral foramina. As a result, the spinal cord, spinal vasculature, and nerve roots can become compressed, leading to the three clinical syndromes that occur with cervical spondylosis: axial neck pain, cervical myelopathy, and cervical radiculopathy. Cervical spondylosis is usually diagnosed for clinical reasons only, but imaging is also required. Treatment for cervical spondylosis can be medical or surgical, depending on whether the patient has symptoms of myelopathy, radicular pain, or neck pain.

Analysis of the uncinate processes of the cervical spine: an anatomical study

2012 ◽  
Vol 16 (4) ◽  
pp. 402-407 ◽  
Author(s):  
R. Shane Tubbs ◽  
Olivia J. Rompala ◽  
Ketan Verma ◽  
Martin M. Mortazavi ◽  
Brion Benninger ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Anatomical Study ◽  
Axial Rotation ◽  
Intervertebral Discs ◽  
Uncinate Process ◽  
Surgical Approaches ◽  
Intervertebral Foramen ◽  
Facet Joints ◽  
Vertebral Level ◽  
Arthritic Changes

Object Although the uncovertebral region is neurosurgically relevant, relatively little is reported in the literature, specifically the neurosurgical literature, regarding its anatomy. Therefore, the present study aimed at further elucidation of this region's morphological features. Methods Morphometry was performed on the uncinate processes of 40 adult human skeletons. Additionally, range of motion testing was performed, with special attention given to the uncinate processes. Finally, these excrescences were classified based on their encroachment on the adjacent intervertebral foramen. Results The height of these processes was on average 4.8 mm, and there was an inverse relationship between height of the uncinate process and the size of the intervertebral foramen. Degeneration of the vertebral body (VB) did not correlate with whether the uncinate process effaced the intervertebral foramen. The taller uncinate processes tended to be located below C-3 vertebral levels, and their average anteroposterior length was 8 mm. The average thickness was found to be 4.9 mm for the base and 1.8 mm for the apex. There were no significant differences found between vertebral level and thickness of the uncinate process. Arthritic changes of the cervical VBs did not necessarily deform the uncinate processes. With axial rotation, the intervertebral discs were noted to be driven into the ipsilateral uncinate process. With lateral flexion, the ipsilateral uncinate processes aided the ipsilateral facet joints in maintaining the integrity of the ipsilateral intervertebral foramen. Conclusions A good appreciation for the anatomy of the uncinate processes is important to the neurosurgeon who operates on the spine. It is hoped that the data presented herein will decrease complications during surgical approaches to the cervical spine.

scholarly journals Development of differentiated surgical technique for treating patients with multilevel degenerative diseases of cervical spine

2019 ◽  
pp. 47-54
Author(s):  
V. A. Byvaltsev ◽  
A. A. Kalinin ◽  
M. A. Aliyev ◽  
V. V. Shepelev ◽  
B. R. Yusupov ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Disease Duration ◽  
Intervertebral Discs ◽  
Adverse Outcomes ◽  
Neurological Symptoms ◽  
Cervical Region ◽  
Degenerative Diseases ◽  
Facet Joints ◽  
On Line ◽  
Surgical Tactics

Background. Currently, there is no uniform tactics for the differentiated use of dorsal decompressive-stabilizing techniques for multilevel degenerative diseases of the cervical spine, and the results of these technologies application are largely controversial.Aim. Analysis of the unsatisfactory outcomes of dorsal decompressive-stabilizing interventions in the treatment of patients with multilevel degenerative diseases of the cervical spine and development of a clinicalinstrumental algorithm for differentiated surgical tactics.Material and methods. A retrospective study included 112 patients with degenerative diseases of the cervical spine at two levels or more due to hernias of intervertebral discs, yellow ligament hypertrophy and arthrosis of facet joints, which in 2007-2014 underwent dorsal decompressive-stabilizing interventions in the volume of laminotomy with laminoplasty (LP) and laminectomy with fixation for lateral masses (LF). A correlation analysis of clinical parameters with anamnestic data, instrumental parameters, a feature of accepted surgical tactics and postoperative adverse effects.Results. In the analysis, it was established that «satisfactory» postoperative outcomes of LP are associated with a neutral or lordotic configuration of the cervical spine, the preservation of segmental movements without clinical and instrumental signs of instability; In addition, the use of LF is possible with mobile kyphotization of the cervical spine and the presence of translational instability of the cervical segments. The «unsatisfactory» postoperative results of the LP and LF are in direct correlation with the duration of the disease, the presence of myelopathic focus and rigid kyphosis of the cervical region.Conclusion. Differential use of dorsal decompressive-stabilizing techniques based on a comprehensive assessment of disease duration, configuration of the cervical spine, spinal cord condition and volume of segmental movements allows to reduce neurological symptoms, improve the level of pain and improve the functional status of patients, as well as significantly reduce the number of adverse outcomes associated with the progression of kyphotic deformity, deterioration of neurological symptoms and revision on-line decompressive-stabilizing interventions. 

Establishment and validation of finite element model of ossification of cervical posterior longitudinal ligament with intervertebral fusion

2020 ◽  
Author(s):  
Li Hui ◽  
Liu Huiqing ◽  
Zhang Yaning
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Posterior Longitudinal Ligament ◽  
Intervertebral Discs ◽  
Biomechanical Analysis ◽  
Intervertebral Fusion ◽  
Dimensional Finite Element

Abstract [Background ]: To establish a three-dimensional finite element model of ossification of the posterior longitudinal ligament of the cervical spine with intervertebral fusion and verify its effectiveness, and provide a platform for finite element calculation and biomechanical analysis in the later stage.[Method]: Select the Department of Spinal Surgery, Linfen People's Hospital A volunteer imported 719 DICOM format images of cervical spine CT scans into Mimics modeling software to build a preliminary 3D model in the stl format, and used Geomagic Studio 2013 software to refine and refine the 3D model to smooth out noise and generate NURBS surfaces The model was then imported into the finite element analysis software Ansys workbench 15.0, adding ligaments and intervertebral discs, meshing, assigning material properties, and simulating 6 activities of the human cervical spine, and comparing them with references.[Results]: A total of 7 Cervical vertebral body, 1 thoracic vertebral body, 5 intervertebral discs and ligaments, etc., with a total of 320512 nodes and 180905 units. It has a realistic appearance, high degree of detail reduction, and ossification of the cervical longitudinal longitudinal ligament with good geometric similarity Incorporate a three-dimensional finite element model of intervertebral fusion. In flexion and extension, left and right lateral flexion, and axial rotation activity compared with references, there is not much difference.[Conclusion]: OPLL merger interbody fusion dimensional finite element model has good mechanical and geometric similarity after similarity cervical established in this study, the model can provide a platform for the latter to further biomechanical analysis.

Intubation biomechanics: validation of a finite element model of cervical spine motion during endotracheal intubation in intact and injured conditions

2018 ◽  
Vol 28 (1) ◽  
pp. 10-22 ◽  
Author(s):  
Benjamin C. Gadomski ◽  
Snehal S. Shetye ◽  
Bradley J. Hindman ◽  
Franklin Dexter ◽  
Brandon G. Santoni ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Finite Element ◽  
Cervical Spine ◽  
Endotracheal Intubation ◽  
Macintosh Laryngoscope ◽  
Element Model ◽  
Fe Model ◽  
Intervertebral Motion ◽  
Model Predictions ◽  
Spine Motion

OBJECTIVEBecause of limitations inherent to cadaver models of endotracheal intubation, the authors’ group developed a finite element (FE) model of the human cervical spine and spinal cord. Their aims were to 1) compare FE model predictions of intervertebral motion during intubation with intervertebral motion measured in patients with intact cervical spines and in cadavers with spine injuries at C-2 and C3–4 and 2) estimate spinal cord strains during intubation under these conditions.METHODSThe FE model was designed to replicate the properties of an intact (stable) spine in patients, C-2 injury (Type II odontoid fracture), and a severe C3–4 distractive-flexion injury from prior cadaver studies. The authors recorded the laryngoscope force values from 2 different laryngoscopes (Macintosh, high intubation force; Airtraq, low intubation force) used during the patient and cadaver intubation studies. FE-modeled motion was compared with experimentally measured motion, and corresponding cord strain values were calculated.RESULTSFE model predictions of intact intervertebral motions were comparable to motions measured in patients and in cadavers at occiput–C2. In intact subaxial segments, the FE model more closely predicted patient intervertebral motions than did cadavers. With C-2 injury, FE-predicted motions did not differ from cadaver measurements. With C3–4 injury, however, the FE model predicted greater motions than were measured in cadavers. FE model cord strains during intubation were greater for the Macintosh laryngoscope than the Airtraq laryngoscope but were comparable among the 3 conditions (intact, C-2 injury, and C3–4 injury).CONCLUSIONSThe FE model is comparable to patients and cadaver models in estimating occiput–C2 motion during intubation in both intact and injured conditions. The FE model may be superior to cadavers in predicting motions of subaxial segments in intact and injured conditions.

Cervical facetectomy and its effect on spine strength

1985 ◽  
Vol 63 (2) ◽  
pp. 278-282 ◽  
Author(s):  
Richard B. Raynor ◽  
James Pugh ◽  
Ilan Shapiro
Keyword(s):  
Cervical Spine ◽  
Facet Joint ◽  
Fracture Load ◽  
Facet Joints ◽  
Shear Tests ◽  
Content Type ◽  
Spine Motion ◽  
Vertebral Bodies ◽  
The Difference ◽  
Anterior Posterior

✓ Fourteen cervical spine motion segments consisting of two adjacent vertebral bodies and their connecting ligaments were tested in shear. Five had intact facet joints, five had bilateral facetectomy of 50% or less, and four had bilateral 70% facetectomy. Three to 5 mm of root could be exposed in the specimens with 50% facetectomy, and 8 to 10 mm in those with 70% facetectomy. Anterior-posterior shear tests were run alternately in compression and distraction. Facetectomy was found to have no effect on compression and distraction stiffness. Failure in the 70% facetectomized specimens was due to fracture of the remaining joint at 159 lbs. In the specimens with 50% facetectomy, a fracture load could not be established since failure of the specimen mounting occurred at 208 lbs, as it did in two of the specimens without facetectomy that were tested to failure. The difference in bone fracture at 159 lbs and mounting failure at 208 lbs is significant at p < 0.05. Bilateral resection of more than 50% of the facet joint significantly compromises the shear strength of a cervical spine motion segment.

Quantifying the ranges of relative motions of the intervertebral discs and facet joints in the normal cervical spine

2020 ◽  
Vol 112 ◽  
pp. 110023 ◽  
Author(s):  
Haiming Wang ◽  
Chaochao Zhou ◽  
Yan Yu ◽  
Cong Wang ◽  
Tsung-Yuan Tsai ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Intervertebral Discs ◽  
Facet Joints ◽  
Relative Motions

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.

CERVICAL SPONDYLOSIS ANATOMY

Neurosurgery ◽  
2007 ◽  
Vol 60 (suppl_1) ◽  
pp. S1-7-S1-13 ◽  
Author(s):  
Daniel Shedid ◽  
Edward C. Benzel
Keyword(s):  
Spinal Cord ◽  
Cervical Spine ◽  
Cervical Spondylosis ◽  
Developmental Process ◽  
Intervertebral Discs ◽  
Mechanical Pressure ◽  
Spine Mobility ◽  
Multiple Levels ◽  
External Forces ◽  
Progressive Disorder

Abstract CERVICAL SPONDYLOSIS IS the most common progressive disorder in the aging cervical spine. It results from the process of degeneration of the intervertebral discs and facet joints of the cervical spine. Biomechanically, the disc and the facets are the connecting structures between the vertebrae for the transmission of external forces. They also facilitate cervical spine mobility. Symptoms related to myelopathy and radiculopathy are caused by the formation of osteophytes, which compromise the diameter of the spinal canal. This compromise may also be partially developmental. The developmental process, together with the degenerative process, may cause mechanical pressure on the spinal cord at one or multiple levels. This pressure may produce direct neurological damage or ischemic changes and, thus, lead to spinal cord disturbances. A thorough understanding of the biomechanics, the pathology, the clinical presentation, the radiological evaluation, as well as the surgical indications of cervical spondylosis, is essential for the management of patients with cervical spondylosis.

Sign in / Sign up

Export Citation Format

Share Document