A Novel Multilayered Annular Model to Predict Delamination in a Lumbar Intervertebral Disc

2009 ◽  
Author(s):  
Raghu N. Natarajan ◽  
Hannah J. Lundberg ◽  
Ted Oegema ◽  
Gunnar B. Andersson
Keyword(s):  
Disc Degeneration ◽  
Radial Direction ◽  
Structural Changes ◽  
Lumbar Disc ◽  
Single Layer ◽  
Element Model ◽  
Intervertebral Discs ◽  
Biomechanical Analysis ◽  
Lumbar Intervertebral Disc

Disc degeneration normally is accompanied by structural changes in the intervertebral discs and the end plates. Reduced level of water in the disc, osteophytes formation and geometrical changes in the end plates also accompany the disc degeneration process. Structural changes in the disc due to degeneration can be classified into radial, peripheral and circumferential tears. Radial tears normally extend from inner annulus region to the outer annulus in the radial direction. These may be due to the failure of annular fibers. Peripheral tears in the annulus normally occur near the junction between the annulus and end plates. These may be due to shear loads at the end plate-annulus junction. Circumferential tears can be observed in both anterior and posterior annulus. These circumferential tears may be due to separation of annular layers due to excess shear between layers and/or due to tensile strain between layers. Although the intrinsic mechanical behavior of the annulus fibrosus as a single layer has been studied, the response of the annulus in vivo does depend on its composite multilayer structure. Biomechanical analysis of the multilayered annulus will help to understand the initiation of delamination failure in the annulus. A finite element model of a lumbar disc with annulus consisting of several layers distributed along the radial direction of the disc with interface was developed to understand the delamination process of the disc under physiological loading modes. It is hypothesized that delamination starts at the inner annular layers near the end plates.

Association between Measures of Vertebral Endplate Morphology and Lumbar Intervertebral Disc Degeneration

2017 ◽  
Vol 68 (2) ◽  
pp. 210-216 ◽  
Author(s):  
Semra Duran ◽  
Mehtap Cavusoglu ◽  
Hatice Gul Hatipoglu ◽  
Deniz Sozmen Cılız ◽  
Bulent Sakman
Keyword(s):  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Lumbar Disc ◽  
Lumbar Disc Degeneration ◽  
Vertebral Endplate ◽  
Lumbar Intervertebral Disc ◽  
Sagittal Diameter ◽  
Magnetic Resonance Imaging Mri ◽  
Vertebral Endplates

Purpose The aim of this study was to evaluate the association between vertebral endplate morphology and the degree of lumbar intervertebral disc degeneration via magnetic resonance imaging (MRI). Methods In total, 150 patients who met the inclusion criteria and were 20–60 years of age were retrospectively evaluated. Patients were evaluated for the presence of intervertebral disc degeneration or herniation, and the degree of degeneration was assessed at all lumbar levels. Vertebral endplate morphology was evaluated based on the endplate sagittal diameter, endplate sagittal concave angle (ECA), and endplate sagittal concave depth (ECD) on sagittal MRI. The association between intervertebral disc degeneration or herniation and endplate morphological measurements was analysed. Results In MRI, superior endplates ( ie, inferior endplates of the superior vertebra) were concave and inferior endplates ( ie, superior endplates of the inferior vertebra) were flat at all disc levels. A decrease in ECD and an increase in ECA were detected at all lumbar levels as disc degeneration increased ( P < .05). At the L4-L5 and L5-S1 levels, a decrease in ECD and an increase in ECA were detected in the group with herniated lumbar discs ( P < .05). There was no association between lumbar disc degeneration or herniation and endplate sagittal diameter at lumbar intervertebral levels ( P > .05). At all levels, ECD of women was significantly lesser than that of men and ECA of women was significantly greater than that of men ( P < .05). Conclusions There is an association between vertebral endplate morphology and lumbar intervertebral disc degeneration. Vertebral endplates at the degenerated disc level become flat; the severity of this flattening is correlated with the degree of disc degeneration.

Biomechanical Effect of Lumbar Disc Degeneration Under Flexion/Extension: A Finite Element Model Study

2007 ◽  
Author(s):  
Lissette M. Ruberté ◽  
Raghu Natarajan ◽  
Gunnar B. J. Andersson
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Disc Degeneration ◽  
Pathological Condition ◽  
Lumbar Disc ◽  
Element Model ◽  
Adjacent Segment ◽  
Lumbar Disc Degeneration ◽  
Flexion Extension

Degenerative disc disease (DDD) is a progressive pathological condition observed in 60 to 80% of the population [1]. It involves changes in both the biochemistry and morphology of the intervertebral disc and is associated with chronic low back pain, sciatica and adult scoliosis [2,3]. The most accepted theory of the effects of DDD on the kinematics of the spine is that proposed by Kirkaldy-Willis and Farfan which states that the condition initiates as a temporary dysfunction, followed by instability and then re-stabilization as the disease progresses [4]. Although there is no clear relationship between disc degeneration and the mechanical behavior of the lumbar spine, abnormal motion patterns either in the form of increased motion or erratic motion have been reported from studies on human cadaveric motion segments [5,6]. To date however no study has looked at how disc degeneration affects the adjacent segment mechanics. IN vivo testing is difficult for these purposes given that specimens are generally obtained from people at the later stages of life and consequently often display multiple pathologies. A finite element model is a viable alternative to study the mechanics of the segments adjacent to the diseased disc. It is hypothesized that moderate degeneration at one level will alter the kinematics of the whole lumbar spine.

Pingyangmycin-Induced In Vivo Lumbar Disc Degeneration Model of Rhesus Monkeys

Spine ◽  
2015 ◽  
Vol 40 (4) ◽  
pp. E199-E210 ◽  
Author(s):  
Fuxin Wei ◽  
Rui Zhong ◽  
Le Wang ◽  
Zhiyu Zhou ◽  
Ximin Pan ◽  
...  
Keyword(s):  
Disc Degeneration ◽  
Rhesus Monkeys ◽  
Lumbar Disc ◽  
Lumbar Disc Degeneration

scholarly journals Efficacy of a virtual reality–based basic and clinical fused curriculum for clinical education on the lumbar intervertebral disc

2021 ◽  
Vol 51 (2) ◽  
pp. E17
Author(s):  
Fangfang Qi ◽  
Yixiang Gan ◽  
Shengwen Wang ◽  
Yizhe Tie ◽  
Jiewen Chen ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Clinical Education ◽  
Structural Changes ◽  
Lumbar Disc ◽  
Three Dimensional ◽  
Patient Specific ◽  
Traditional Teaching ◽  
Traditional Group ◽  
Lumbar Intervertebral Disc ◽  
Surgical Preparation

OBJECTIVE Today, minimally invasive procedures have become mainstream surgical procedures. Percutaneous endoscopic transforaminal discectomy for lumbar disc herniation (LDH) requires profound knowledge of the laparoscopic lumbar anatomy. Immersive virtual reality (VR) provides three-dimensional patient-specific models to help in the process of preclinical surgical preparation. In this study, the authors investigated the efficacy of VR application in LDH for training orthopedic residents and postgraduates. METHODS VR images of the lumbar anatomy were created with immersive VR and mAnatomy software. The study was conducted among 60 residents and postgraduates. A questionnaire was developed to assess the effect of and satisfaction with this VR-based basic and clinical fused curriculum. The teaching effect was also evaluated through a postlecture test, and the results of the prelecture surgical examination were taken as baselines. RESULTS All participants in the VR group agreed that VR-based education is practical, attractive, and easy to operate, compared to traditional teaching, and promotes better understanding of the anatomical structures involved in LDH. Learners in the VR group achieved higher scores on an anatomical and clinical fusion test than learners in the traditional group (84.67 ± 14.56 vs 76.00 ± 16.10, p < 0.05). CONCLUSIONS An immersive VR-based basic and clinical fused curriculum can increase residents’ and postgraduates’ interest and support them in mastering the structural changes and complicated symptoms of LDH. However, a simplified operational process and more realistic haptics of the VR system are necessary for further surgical preparation and application.

scholarly journals Biomechanics Of Human Lumbar Spine (L3 To L5) With Degenerative Disc Disease Using Finite Element Model

2019 ◽  
Vol 8 (6) ◽  
pp. 4609-4614
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Disc Degeneration ◽  
Human Body ◽  
Lumbar Disc ◽  
Element Model ◽  
Human Spine ◽  
Human Lumbar Spine ◽  
Normal Human

Human spine is one of the complex structure of the human body. It provides the link between upper and lower extremities of the human body. It is estimated that at least 30% of people in the middle age group from thirty to fifty years have some degree of disc degeneration. Disc degeneration disease can affect the quality of life and in certain individual it can cause severe chronic pain if left untreated. The low back pain associated with lumbar disc degeneration is usually generated from two causes which are abnormal motion instability and inflammation. Abnormal motion instability occurs when the annulus fibrosus are worn down and cannot absorb stress on the human spine effectively resulting in changes in movements along the vertebral segment. To understand lumbar disc problem, a thorough knowledge of the biomechanics of the normal human lumbar spine and a disc degenerated lumbar spine is of great importance. In this study, Computed tomography image of a 33 year old male is used. A three dimensional (3D) human lumbar spine (L3 to L5) is created and validated with literature. The finite element model was modified to degenerated disc and studied the biomechanics of the lumbar spine. Comparison of the biomechanics of normal human lumbar spine is done with the human lumbar spine with disc degeneration for different range of motion and different loads. The result shows that the pressure generated on degenerated disc is greater than normal disc. This work can be implemented and used for designing implants and also for intervertebral disc related analysis

Intervertebral Disc Function Is Restored in an In Vivo Model of Chronic Nucleus Pulposus Glycosaminoglycan Reduction

2008 ◽  
Author(s):  
John I. Boxberger ◽  
Joshua D. Auerbach ◽  
Sounok Sen ◽  
George R. Dodge ◽  
Dawn M. Elliott
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Lumbar Disc ◽  
Post Treatment ◽  
In Vivo Model ◽  
Long Term Effects ◽  
Early Human

Reduced nucleus pulposus glycosaminoglycan (GAG) content is one of the earliest clinically detectable changes during the course of intervertebral disc degeneration [1,2]. Depletion of nucleus GAG by small percentages consistent with this early loss has been experimentally linked to altered motion segment mechanical function, and thus, potentially increases the risk of damage accumulation directly due to elevated stresses and strains and through altered cellular function [3]. Recently, our laboratory has established an in vivo model in a rat lumbar disc which moderately decreases nucleus GAG to levels observed in early human degeneration. In this model, GAG loss is accompanied by a state of hypermobility at both 4 and 12 weeks post treatment [4], potentially making the disc susceptible to mechanical failure. The objective of this study was to determine the long term effects of nucleus GAG depletion and to determine if altered discs demonstrate hallmark features of disc degeneration. We hypothesized that GAG will remain depleted 24 weeks post treatment, potentially decreasing to lower levels, and further that geometrical and mechanical changes consistent with degeneration will be observed.

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.

scholarly journals Development of a Detailed Volumetric Finite Element Model of the Spine to Simulate Surgical Correction of Spinal Deformities

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mark Driscoll ◽  
Jean-Marc Mac-Thiong ◽  
Hubert Labelle ◽  
Stefan Parent
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Finite Element Model ◽  
Ex Vivo ◽  
Spinal Instrumentation ◽  
Element Model ◽  
Patient Data ◽  
Biomechanical Analysis ◽  
Published Data

A large spectrum of medical devices exists; it aims to correct deformities associated with spinal disorders. The development of a detailed volumetric finite element model of the osteoligamentous spine would serve as a valuable tool to assess, compare, and optimize spinal devices. Thus the purpose of the study was to develop and initiate validation of a detailed osteoligamentous finite element model of the spine with simulated correction from spinal instrumentation. A finite element of the spine from T1 to L5 was developed using properties and geometry from the published literature and patient data. Spinal instrumentation, consisting of segmental translation of a scoliotic spine, was emulated. Postoperative patient and relevant published data of intervertebral disc stress, screw/vertebra pullout forces, and spinal profiles was used to evaluate the models validity. Intervertebral disc and vertebral reaction stresses respected publishedin vivo,ex vivo, andin silicovalues. Screw/vertebra reaction forces agreed with accepted pullout threshold values. Cobb angle measurements of spinal deformity following simulated surgical instrumentation corroborated with patient data. This computational biomechanical analysis validated a detailed volumetric spine model. Future studies seek to exploit the model to explore the performance of corrective spinal devices.

Menopause is associated with lumbar disc degeneration: a review of 4230 intervertebral discs

Climacteric ◽  
2014 ◽  
Vol 17 (6) ◽  
pp. 700-704 ◽  
Author(s):  
C. Lou ◽  
H-L. Chen ◽  
X-Z. Feng ◽  
G-H. Xiang ◽  
S-P. Zhu ◽  
...  
Keyword(s):  
Disc Degeneration ◽  
Lumbar Disc ◽  
Intervertebral Discs ◽  
Lumbar Disc Degeneration

scholarly journals The influence of the nucleus pulposus on the stress distribution in the natural and prosthetic intervertebral disc

2019 ◽  
Vol 252 ◽  
pp. 07006 ◽  
Author(s):  
Robert Karpiński ◽  
Łukasz Jaworski ◽  
Józef Jonak ◽  
Przemysław Krakowski
Keyword(s):  
Stress Distribution ◽  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Inner Core ◽  
Lumbar Vertebrae ◽  
Fem Analysis ◽  
3D Models ◽  
Intervertebral Discs ◽  
Biomechanical Analysis ◽  
Lumbar Intervertebral Disc

The aim of this article was to present the results of a preliminary study on the stress distribution in the lumbar intervertebral disc [IVD] under loads induced during daily activities. Basic anatomy, biomechanical analysis of the vertebra and intervertebral disc were introduced. The third and fourth lumbar vertebrae were chosen for the study because they carry considerably higher loads, especially while standing or sitting. The static mechanical analyses using the finite element method (FEM) were conducted for four standard loads reflecting patient’s positions: recumbent, standing, sitting and standing with additional loads, and three models: an intervertebral disc with an inner nucleus pulposus and two prosthetic intervertebral discs, with or without an artificial nucleus. The FEM analysis was performed in the SolidWorks Simulation module on reverse-engineered 3D models of vertebrae and the intervertebral disc, based on a series of computed tomography [CT] scans of the patient’s spine, which had been properly processed in Materialise Mimics software and exported to CAD files. The model of the fourth intervertebral disc, placed between third and fourth vertebra, had been additionally modified to include its inner core, the nucleus pulposus.

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