scholarly journals RESEARCH ON THE INFLUENCE OF THE PROPERTIES OF INTERVERTEBRAL DISC STIFFNESS OF THE LUMBAR SPINE ON THE DISPLACEMENT OF VERETBRAE / STUBURO JUOSMENINĖS DALIES TARPSLANKSTELINIO DISKO STANDUMO CHARAKTERISTIKŲ ĮTAKOS SLANKSTELIŲ POSLINKIAMS TYRIMAS

2015 ◽  
Vol 6 (6) ◽  
pp. 595-597
Author(s):  
Artūras Linkel ◽  
Julius Griškevičius ◽  
Gintaras Jonaitis
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Degrees Of Freedom ◽  
Angular Displacement ◽  
Fast Response ◽  
Intervertebral Discs ◽  
Linear Displacement ◽  
Basic Task ◽  
Non Linear ◽  
Solid Bodies

The article proposes the method for evaluating angular and linear changes in intervertebral discs of the spine depending on linear and nonlinear intervertebral disc stiffness. A dynamic made of 5 solid bodies connected by damping and stiffness components and applied for 2-D 10 degrees of freedom of the lumbar spine has been used for calculations. The system of the equation has been written in a matrix form. Lumbar intervertebral discs stiffness and damping properties have been selected from scientific articles and make from 200 N/mm to 1200 N/mm and from 229 Ns / mm to 5100 Ns/mm respectively for non-linear calculation and 800 N / mm – 2637 Ns/mm for linear displacement calculation. External loads applied to the model are 1648 N, 2957 N, 3863 N and 4542 N. The basic task of the paper is to calculate the biggest difference in linear and angular displacement considering 2 cases: linear and non-linear stiffness value. The greatest estimated difference, under the highest load, makes 0.6 mm for linear and 0.95 degrees for angular displacement. Because of the fast response of the model to the load, the damping value could not affect displacement. Tyrimo objektas yra stuburo trapslankstelinių diskų poslinkių skirtumai esant tiesiniam ir netiesiniam jų standumo koeficientui. Taikomas 10 laisvės laipsnių 2-D stuburo juosmeninės dalies dinaminis modelis, kuris susideda iš 5 juosmens slankstelių, sujungtų standumo ir slopinimo ryšiais. Modeliui nustatomos juosmens apkrovos, kurios susidaro važiuojant dviračiu. Tarpslankstelinių diskų savybės parenkamos iš mokslinės literatūros. Sudarytas matematinis modelis leido apskaičiuoti stuburo slankstelių linijinius ir kampinius poslinkius įvertinant tarpslankstelinio disko standžio netiesiškumą. Atlikti skaičiavimai parodė, kad didžiausi skirtumai susidaro esant maksimaliai apkrovai. Didžiausi linijinių poslinkių skirtumai yra 0,6 mm, o kampinių – 0,95 laipsnio. Nustatytos slopinimo koeficiento reikšmės dėl greito modelio atsako poslinkių skaičiavimams įtakos neturėjo.

scholarly journals A non-linear multiaxial fatigue damage model for the cervical intervertebral disc annulus

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401877949 ◽  
Author(s):  
Shruti Motiwale ◽  
Adhitya Subramani ◽  
Reuben H Kraft ◽  
Xianlian Zhou
Keyword(s):  
Cervical Spine ◽  
Cyclic Loading ◽  
Neck Pain ◽  
Intervertebral Disc ◽  
Fatigue Damage ◽  
Disc Degeneration ◽  
Intervertebral Discs ◽  
Quantitative Prediction ◽  
Biomechanical Models ◽  
Non Linear

A significant portion of the military population develops severe neck pain in the course of their duties. It has been hypothesized that neck pain is a consequence of accelerated degeneration of the intervertebral discs in the cervical spine, but more occupational and mechanistic-based tools and research are needed to positively confirm the link between neck pain and accelerated disc degeneration. Heavy head-supported mass including helmets and accessories worn by military personnel may subject the intervertebral discs of the cervical spine to complex cyclic loading profiles. In addition, some military operational travel which includes riding on high speed planing boats has also been reported to result in high magnitude cyclic loading on cervical spine discs. In this article, we present a methodology to computationally predict fatigue damage to cervical intervertebral discs over extended periods of time, by integrating kinematics-based biomechanical models with a continuum damage mechanics-based theory of disc degeneration. Through this computational approach, we can gain insights into the relationship between these military activities and possible accelerated fatigue degeneration of cervical intervertebral discs and provide a quantitative prediction tool for decade-long time ranges. The four significant improvements this computational framework adds to the area of modeling intervertebral disc degeneration are the following: (a) it addresses the non-linear nature of fatigue damage evolution, (b) it includes the effect of aging and damage recovery to accurately simulate biological phenomena, (c) it computes fatigue damage taking into account the multiaxial stress state in the disc, and (d) it correlates the computational damage parameter with established clinical grading systems for disc degeneration.

scholarly journals Retroperitoneal oblique corridor to the L2–S1 intervertebral discs: an MRI study

2016 ◽  
Vol 24 (2) ◽  
pp. 248-255 ◽  
Author(s):  
Diana M. Molinares ◽  
Timothy T. Davis ◽  
Daniel A. Fung
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Vertebral Body ◽  
Psoas Muscle ◽  
Intervertebral Discs ◽  
Mr Images ◽  
Disc Space ◽  
Iliac Vessel ◽  
Medial Border ◽  
Transpsoas Approach

OBJECT The purpose of this study was to analyze MR images of the lumbar spine and document: 1) the oblique corridor at each lumbar disc level between the psoas muscle and the great vessels, and 2) oblique access to the L5–S1 disc space. Access to the lumbar spine without disruption of the psoas muscle could translate into decreased frequency of postoperative neurological complications observed after a transpsoas approach. The authors investigated the retroperitoneal oblique corridor of L2–S1 as a means of surgical access to the intervertebral discs. This oblique approach avoids the psoas muscle and is a safe and potentially superior alternative to the lateral transpsoas approach used by many surgeons. METHODS One hundred thirty-three MRI studies performed between May 4, 2012, and February 27, 2013, were randomly selected from the authors’ database. Thirty-three MR images were excluded due to technical issues or altered lumbar anatomy due to previous spine surgery. The oblique corridor was defined as the distance between the left lateral border of the aorta (or iliac artery) and the anterior medial border of the psoas. The L5–S1 oblique corridor was defined transversely from the midsagittal line of the inferior endplate of L-5 to the medial border of the left common iliac vessel (axial view) and vertically to the first vascular structure that crossed midline (sagittal view). RESULTS The oblique corridor measurements to the L2–5 discs have the following mean distances: L2–3 = 16.04 mm, L3–4 = 14.21 mm, and L4–5 = 10.28 mm. The L5–S1 corridor mean distance was 10 mm between midline and left common iliac vessel, and 10.13 mm from the first midline vessel to the inferior endplate of L-5. The bifurcation of the aorta and confluence of the vena cava were also analyzed in this study. The aortic bifurcation was found at the L-3 vertebral body in 2% of the MR images, at the L3–4 disc in 5%, at the L-4 vertebral body in 43%, at the L4–5 disc in 11%, and at the L-5 vertebral body in 9%. The confluence of the iliac veins was found at lower levels: 45% at the L-4 level, 19.39% at the L4–5 intervertebral disc, and 34% at the L-5 vertebral body. CONCLUSIONS An oblique corridor of access to the L2–5 discs was found in 90% of the MR images (99% access to L2–3, 100% access to L3–4, and 91% access to L4–5). Access to the L5–S1 disc was also established in 69% of the MR images analyzed. The lower the confluence of iliac veins, the less probable it was that access to the L5–S1 intervertebral disc space was observed. These findings support the use of lumbar MRI as a tool to predetermine the presence of an oblique corridor for access to the L2–S1 intervertebral disc spaces prior to lumbar spine surgery.

scholarly journals Convergence analysis and validation of a discrete element model of the human lumbar spine

2022 ◽  
Vol 3 (1) ◽  
pp. 62-70
Author(s):  
Galina Eremina ◽  
◽  
Alexey Smolin ◽  
Irina Martyshina ◽  
◽  
...  
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Bone Tissue ◽  
Vertebral Body ◽  
Loading Rate ◽  
Numerical Models ◽  
Fold Increase ◽  
Intervertebral Discs ◽  
Effective Stiffness ◽  
Structural Element

Degenerative diseases of the spine can lead to or hasten the onset of additional spinal problems that significantly reduce human mobility. The spine consists of vertebral bodies and intervertebral discs. The most degraded are intervertebral discs. The vertebral body consists of a shell (cortical bone tissue) and an internal content (cancellous bone tissue). The intervertebral disc is a complex structural element of the spine, consisting of the nucleus pulposus, annulus fibrosus, and cartilaginous plates. To develop numerical models for the vertebral body and intervertebral disc, first, it is necessary to verify and validate the models for the constituent elements of the lumbar spine. This paper, for the first time, presents discrete elements-based numerical models for the constituent parts of the lumbar spine, and their verification and validation. The models are validated using uniaxial compression experiments available in the literature. The model predictions are in good qualitative and quantitative agreement with the data of those experiments. The loading rate sensitivity analysis revealed that fluid-saturated porous materials are highly sensitive to loading rate: a 1000-fold increase in rate leads to the increase in effective stiffness of 130 % for the intervertebral disc, and a 250-fold increase in rate leads to the increase in effective stiffness of 50 % for the vertebral body. The developed model components can be used to create an L4-L5 segment model, which, in the future, will allow investigating the mechanical behavior of the spine under different types of loading.

Patient-specific spine models. Part 1: Finite element analysis of the lumbar intervertebral disc—a material sensitivity study

2002 ◽  
Vol 216 (5) ◽  
pp. 299-314 ◽  
Author(s):  
M J Fagan ◽  
S Julian ◽  
D J Siddall ◽  
A M Mohsen
Keyword(s):  
Finite Element ◽  
Intervertebral Disc ◽  
Material Properties ◽  
Intervertebral Discs ◽  
Basic Material ◽  
Patient Specific ◽  
Finite Element Models ◽  
Torsional Loading ◽  
Non Linear ◽  
Linear Material

If patient-specific finite element models of the spine could be developed, they would offer enormous opportunities in the diagnosis and management of back problems. Several generic models have been developed in the past, but there has been very little detailed examination of the sensitivity of these models' characteristics to the input parameters. This relationship must be thoroughly understood if representative patient-specific models are to be realized and used with confidence. In particular, the performance of the intervertebral discs are central to any spine model and need detailed investigation first. A generic non-linear model of an intervertebral disc was developed and subjected to compressive, flexion and torsional loading regimes. The effects of both material and geometric non-linearities were investigated for the three loading schemes and the results compared with experimental data. The basic material properties of the fibres, annulus and nucleus were then varied and the effects on the stiffness, annulus bulge and annulus stresses analysed. The results showed that the non-linear geometry assumption had a significant effect on the compression characteristics, whereas the non-linear material option did not. In contrast, the material non-linearity was more important for the flexural and torsional loading schemes. Thus, the inclusion of non-linear material and geometry analysis options in finite element models of intervertebral discs is necessary to predict in vivo load-deflection characteristics accurately. When the influence of the material properties was examined in detail, it was found that the fibre properties did not have a significant effect on the compressive stiffness of the disc but did affect the flexural and torsional stiffnesses by up to ±20 per cent. All loading modes were sensitive to the annulus properties with stiffnesses varying by up to ±16 per cent. The model also revealed that for a particular compressive deformation or flexural or torsional rotation, the disc bulge was not sensitive to any of the material properties over the range of properties considered. The annulus stresses did differ significantly as the material properties were varied (up to 70 per cent under a compressive load and 60 per cent during disc flexion).

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.

Selection of retroperitoneal access during intervertebral disc endoprosthesis in lumbar spine

2021 ◽  
Vol 23 (1) ◽  
pp. 73-80
Author(s):  
Maxim A. Priymak ◽  
Ivan A. Kruglov ◽  
Alexei I. Gaivoronski ◽  
Maksim N. Kravtsov ◽  
Gennady G. Bulyshchenko
Keyword(s):  
Lumbar Spine ◽  
Inferior Vena Cava ◽  
Intervertebral Disc ◽  
Inferior Vena ◽  
Vena Cava ◽  
Iliac Vein ◽  
Intervertebral Discs ◽  
Skin Incision ◽  
Common Iliac Vein ◽  
Left Common Iliac Vein

The morphometric parameters and surgical areas of risk of retroperitoneal approach were studied for endoprosthetics of intervertebral discs in the lumbar spine to reduce trauma and reduce the risk of complications. The study included 110 patients operated on in the period from 2017 to 2020 (72 men, 38 women) in the neurosurgical department of the 1586 Military Clinical Hospital. The average age of the patients was 44.9 15.4 years. According to the localization of access to the lumbar spine, the patients were distributed as follows: LIIILIV 8 (7.3%), LIVLV 46 (41.7%), LVSI 56 (51%). It was found that, for the intervertebral disc LV SI, the length of the skin incision was 92.5 (80; 100) mm, the length of the surgical wound was 80 (80; 110) mm, the thickness of the subcutaneous fat layer was 30 (15; 40) mm, the depth of the wound was to the spine 85 (70; 120) mm, the depth of the wound to the spinal canal 125 (107.5; 152.5) mm, the angle of operation in the horizontal plane at the level of the spine 52 (47; 59.5) degrees. On the basis of the anthropometric data of patients, the optimal length of the skin incision was determined for performing the retroperitoneal approach (120 mm for level LIIILIV, 100 mm for level LIVLV). Three variants of the inferior vena cava bifurcation have been identified for different levels of intervertebral discs in the lumbar spine: high bifurcation, left common iliac vein mainly overlaps the left half of the LIVLV intervertebral disc and does not overlap the LVSI intervertebral disc; middle bifurcation, left common iliac vein overlaps the central part of the intervertebral discs LIVLV and LVSI; low bifurcation, inferior vena cava overlaps the right side of the intervertebral disc LIVLV, inferior vena cava and left common iliac vein completely overlap the intervertebral disc LVSI. The data obtained can be used when planning retroperitoneal access to the lumbar spine in order to reduce the trauma of the operation.

Mechanical yield of the lumbar annulus: a possible contributor to instability

2014 ◽  
Vol 21 (4) ◽  
pp. 608-613 ◽  
Author(s):  
Brian D. Stemper ◽  
Jamie L. Baisden ◽  
Narayan Yoganandan ◽  
Barry S. Shender ◽  
Dennis J. Maiman
Keyword(s):  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Mechanical Response ◽  
Facet Joint ◽  
Intervertebral Discs ◽  
Stress And Strain ◽  
Anatomical Region ◽  
Linear Elastic ◽  
Load Carrying ◽  
Ultimate Failure

Object Segmental instability in the lumbar spine can result from a number of mechanisms including intervertebral disc degeneration and facet joint degradation. Under traumatic circumstances, elevated loading may lead to mechanical yield of the annular fibers, which can decrease load-carrying capacity and contribute to instability. The purpose of this study was to quantify the biomechanics of intervertebral annular yield during tensile loading with respect to spinal level and anatomical region within the intervertebral disc. Methods This laboratory-based study incorporated isolated lumbar spine annular specimens from younger and normal or mildly degenerated intervertebral discs. Specimens were quasi-statically distracted to failure in an environmentally controlled chamber. Stress and strain associated with yield and ultimate failure were quantified, as was stiffness in the elastic and postyield regions. Analysis of variance was used to determine statistically significant differences based on lumbar spine level, radial position, and anatomical region of the disc. Results Annular specimens demonstrated a nonlinear response consisting of the following: toe region, linear elastic region, yield point, postyield region, and ultimate failure point. Regional dependency was identified between deep and superficial fibers. Mechanical yield was evident prior to ultimate failure in 98% of the specimens and occurred at approximately 80% and 74% of the stress and strain, respectively, to ultimate failure. Fiber modulus decreased by 34% following yield. Conclusions Data in this study demonstrated that yielding of intervertebral disc fibers occurs relatively early in the mechanical response of the tissues and that stiffness is considerably decreased following yield. Therefore, yielding of annular fibers may result in decreased segmental stability, contributing to accelerated degeneration of bony components and possible idiopathic pain.

scholarly journals Vertebral instability of lumbar spine and its neurological presentations

Pain medicine ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 37-42
Author(s):  
A. M. Vitkovskyi
Keyword(s):  
Lumbar Spine ◽  
Sagittal Plane ◽  
Clinical Signs ◽  
Axial Rotation ◽  
Intervertebral Discs ◽  
Linear Displacement ◽  
Patient Treatment ◽  
Spinal Motion ◽  
X Ray ◽  
Surgery Department

 Background. The research results of data of 57 patients with vertebral instability of lumbar spine with neurological presentations are presented. Patients were on in-patient treatment at the Vertebral surgery department of Institute of Traumatology and Orthopedics (Kyiv) in 2010–2014. Research object. The aim of the research was to determine the features of clinical signs and X-ray measures depending on type and stage of instability in lumbar spine. Materials and methods. The research is based on the analysis of management of 57 patients with lumbar spine instability. The management consisted of anamnesis, examination of patients, X-ray of spine, MRI and CT. The majority of patients were males. There were 35 (61.4 %) males, 22 (38.6 %) females among all of the patients. Due to the data of the research it was inquired that the spine instability was detected frequently in the most employable age, from 20 to 44 years – 30 (52.6 %) cases. Results and discussion. The spine instability is clinical and radiographic manifestation of pathological removability of contiguous vertebras due to each other. This resulted in lesion of vertebras and adjoined vessels and nerves, caused by inadequate supporting system of spinal motion segments. Failure of spinal motion segments develops mainly in degenerative and dystrophic disorders resulted in acute or chronic congestions influenced by microtraumas. Development of secondary lesions of spine and spinal radixes are affected by deformation of spine and spinal channel. Emerging of pathological processes is accompanied by orthopedic and neurological presentations, that requiring surgical correction. Conclusions. Instability of VMS is caused by structure alteration of intervertebral discs, aquatics and processes joints and a part of vertebral arc between joints. Clinical signs depend on the level of localization and the stage of spine instability. Among patients with spine instability the manifestation of radixes lesions were on the 1st place – 29 (50.9 %) cases, on the 2nd place – lesions of lumbago – 19 (33.3 %) cases. X-ray features of instability are: enlargement of linear displacement of vertebral body in sagittal plane more than 4.5 mm, segmental axial rotation of vertebra – more than 40°.

Melatonin: Protection of the Intervertebral Disc

2019 ◽  
Vol 2 (3) ◽  
pp. 1-9
Author(s):  
Russel J Reiter ◽  
Sergio Rosales-Corral ◽  
Ramaswamy Sharma
Keyword(s):  
Intervertebral Disc ◽  
Molecular Mechanisms ◽  
Intervertebral Discs ◽  
Lumbar Pain ◽  
Low Back ◽  
Work Time ◽  
Protective Actions ◽  
Aging Populations ◽  
Definition Of ◽  
Endogenous Melatonin

     Low back pain (lumbar pain) due to injury of or damage to intervertebral discs is common in all societies.  The loss of work time as a result of this problem is massive.  Recent research suggests that melatonin may prevent or counteract intervertebral disc damage. This may be especially relevant in aging populations given that endogenous melatonin, in most individuals, dwindles with increasing age. The publications related to melatonin and its protection of the intervertebral disc are reviewed herein, including definition of some molecular mechanisms that account for melatonin’s protective actions. 

EXPERIENCE OF CONSERVATIVE TREATMENT OF INTERVERTEBRAL DISC HERNIAS WITH CARIFLEX GEL AND CREAM IN AMBULATORY CONDITIONS

2020 ◽  
Vol 3 (1) ◽  
pp. 6-8
Author(s):  
Zufar ADAMBAEV ◽  
◽  
Ibodulla KILICHEV ◽  
Tuygunoy XODJANOVA
Keyword(s):  
Comparative Analysis ◽  
Conservative Treatment ◽  
Intervertebral Disc ◽  
Range Of Motion ◽  
Comparative Evaluation ◽  
Intervertebral Discs ◽  
Neurological Manifestations ◽  
Complex Therapy

A complex therapy of patients with degenerative-dystrophic diseases of the spine with herniated intervertebral discs with neurological manifestations was carried out with the addition of phonophoresis Kariflex gel followed by segmental massage with Kariflex cream. The comparative evaluation of the method was carried out in 89 patients. Comparative analysis revealed the reliable efficiency of the method used. Against the background of the proposed therapy, there was a significant decrease in pain and muscle-tonic syndromes, an increase in the range of motion in the spine

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