A comparison between porcine, ovine, and bovine intervertebral disc anatomy and single lamella annulus fibrosus tensile properties

2015 ◽  
Vol 277 (2) ◽  
pp. 244-251 ◽  
Author(s):  
Lauren A. Monaco ◽  
Stephanie J. DeWitte-Orr ◽  
Diane E. Gregory
Keyword(s):  
Intervertebral Disc ◽  
Tensile Properties ◽  
Annulus Fibrosus

scholarly journals P.097 Tensile properties of Polyvinyl Alcohol Cryogel (PVA-C) formulations and generation of a tissue mimicking artificial lumbar intervertebral disc prototype

2017 ◽  
Vol 44 (S2) ◽  
pp. S38-S38
Author(s):  
BH Wang ◽  
K Gurr ◽  
C Bailey ◽  
G Campbell
Keyword(s):  
Elastic Modulus ◽  
Intervertebral Disc ◽  
Tensile Properties ◽  
Annulus Fibrosus ◽  
Symptom Relief ◽  
Porous Titanium ◽  
Lumbar Intervertebral Disc ◽  
Pull Out ◽  
Simple Tension ◽  
Order Of Magnitude

Background: Current lumbar intervertebral disc prostheses provide suboptimal symptom relief with little natural load-cushioning. PVA-C is a promising biocompatible material, however previous studies from our lab show that it does not have adequate elastic modulus to mimic the annulus fibrosus. Here we present a prototype of an artificial lumbar intervertebral disc. Methods: The tensile properties of pure (5-35% PVA-C) and particle-reinforced (15% PVA-C with 5% of either Sephadex or hydroxyapatite) composite PVA-C formulations were evaluated. Simple tension and tensile stress relaxation tests were performed. Woven Teflon mesh was embedded in PVA-C and tested under compression. Endplate pull-out tests were performed. Results: Tensile testing showed that all PVA-C formulations behaved linearly for physiologic levels of strain (<20%). Tensile elastic modulus is an order of magnitude lower than the annulus fibrosus. Teflon has similar elastic modulus as collagen and compression of the hybrid Teflon-PVA-C construct revealed good biomechanical mimicry with elastic modulus of 20-25MPa at 20% deformation, similar to human data. Bonding between PVA-C and porous titanium endplate is excellent. Conclusions: A fiber-reinforced PVA-C impregnated composite adequately mimics the annulus fibrosus. Our prototype of a tissue mimicking artificial intervertebral disc utilizes a woven Teflon fiber with 20% PVA-C (+Hydroxyapatite) annulus and 5% pure PVA-C nucleus bonded to porous titanium foam endplates.

scholarly journals Biochemical and Immuno-Histochemical Localization of Type IIA Procollagen in Annulus Fibrosus of Mature Bovine Intervertebral Disc

2021 ◽  
pp. 100077
Author(s):  
Audrey McAlinden ◽  
David M. Hudson ◽  
Aysel A. Fernandes ◽  
Soumya Ravindran ◽  
Russell J. Fernandes
Keyword(s):  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Histochemical Localization

scholarly journals Lactate oxidative phosphorylation by annulus fibrosus cells: evidence for lactate-dependent metabolic symbiosis in intervertebral discs

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Dong Wang ◽  
Robert Hartman ◽  
Chao Han ◽  
Chao-ming Zhou ◽  
Brandon Couch ◽  
...  
Keyword(s):  
Amino Acids ◽  
Lactic Acid ◽  
Oxidative Phosphorylation ◽  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Tca Cycle ◽  
Heavy Isotope ◽  
In Vivo Models ◽  
Disc Tissue ◽  
Tca Cycle Intermediates

Abstract Background Intervertebral disc degeneration contributes to low back pain. The avascular intervertebral disc consists of a central hypoxic nucleus pulpous (NP) surrounded by the more oxygenated annulus fibrosus (AF). Lactic acid, an abundant end-product of NP glycolysis, has long been viewed as a harmful waste that acidifies disc tissue and decreases cell viability and function. As lactic acid is readily converted into lactate in disc tissue, the objective of this study was to determine whether lactate could be used by AF cells as a carbon source rather than being removed from disc tissue as a waste byproduct. Methods Import and conversion of lactate to tricarboxylic acid (TCA) cycle intermediates and amino acids in rabbit AF cells were measured by heavy-isotope (13C-lactate) tracing experiments using mass spectrometry. Levels of protein expression of lactate converting enzymes, lactate importer and exporter in NP and AF tissues were quantified by Western blots. Effects of lactate on proteoglycan (35S-sulfate) and collagen (3H-proline) matrix protein synthesis and oxidative phosphorylation (Seahorse XFe96 Extracellular Flux Analyzer) in AF cells were assessed. Results Heavy-isotope tracing experiments revealed that AF cells imported and converted lactate into TCA cycle intermediates and amino acids using in vitro cell culture and in vivo models. Addition of exogenous lactate (4 mM) in culture media induced expression of the lactate importer MCT1 and increased oxygen consumption rate by 50%, mitochondrial ATP-linked respiration by 30%, and collagen synthesis by 50% in AF cell cultures grown under physiologic oxygen (2-5% O2) and glucose concentration (1-5 mM). AF tissue highly expresses MCT1, LDH-H, an enzyme that preferentially converts lactate to pyruvate, and PDH, an enzyme that converts pyruvate to acetyl-coA. In contrast, NP tissue highly expresses MCT4, a lactate exporter, and LDH-M, an enzyme that preferentially converts pyruvate to lactate. Conclusions These findings support disc lactate-dependent metabolic symbiosis in which lactate produced by the hypoxic, glycolytic NP cells is utilized by the more oxygenated AF cells via oxidative phosphorylation for energy and matrix production, thus shifting the current research paradigm of viewing disc lactate as a waste product to considering it as an important biofuel. These scientifically impactful results suggest novel therapeutic targets in disc metabolism and degeneration.

The Influence of Axial Compression on the Cellular and Mechanical Function of Spinal Tissues; Emphasis on The Nucleus Pulposus and Annulus Fibrosus

2021 ◽  
Author(s):  
John McMorran ◽  
Diane Gregory
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Axial Compression ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Intervertebral Disc Degeneration ◽  
Chronic Back Pain ◽  
Physiological State ◽  
Movement Pattern ◽  
Mechanical Function

Abstract In light of the correlation between chronic back pain and intervertebral disc degeneration, this literature review seeks to illustrate the importance of the hydraulic response across the nucleus pulposus- annulus fibrosus interface, by synthesizing current information regarding injurious biomechanics of the spine, stemming from axial compression. Damage to vertebrae, endplates, the nucleus pulposus, and the annulus fibrosus, can all arise from axial compression, depending on the segment's posture, the manner in which it is loaded, and the physiological state of tissue. Therefore, this movement pattern was selected to illustrate the importance of the bracing effect of a pressurized nucleus pulposus on the annulus fibrosus, and how injuries interrupting support to the annulus fibrosus may contribute to intervertebral disc degeneration.

scholarly journals Early differentation of lamellar structure of the intervertebral disc in staged human embryos

2015 ◽  
Vol 84 (3) ◽  
pp. 157-166
Author(s):  
Witold Woźniak ◽  
Małgorzata Grzymisławska ◽  
Joanna Łupicka ◽  
Małgorzata Bruska ◽  
Adam Piotrowski ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Developmental Stages ◽  
Intervertebral Discs ◽  
Human Embryos ◽  
Lateral Zone ◽  
Vast Literature ◽  
Dense Zone

Introduction. In the vast literature concerning the development of the intervertebral discs controversies exist as to the period of differentiation and structure of the nucleus pulposus and annulus fibrosus. These controversies result from different determination of age of the investigated embryos. Aim. Using embryos from departmental collection age of which was established according to international Carnegie staging and expressed in postfertilizational days, the differentiation of the intervertebral discs was traced. Material and methods. Study was performed on 34 embryos at developmental stages 13–23 (32–56 days). Embryos were serially sectioned in sagittal, frontal and horizontal planes. Sections were stained with various histological methods and impregnated with silver.Results. Division of sclerotomes into loose cranial and dense caudal zones (sclerotomites) was observed in embryos aged 32 days (stage 13). The intervertebral disc developed from the dense zone of sclerotome and was well recognized in embryos aged 33 days (stage 14). At the end of fifth week (embryos at stage 15, 36 days) the annulus fibrosus and the nucleus pulposus were seen. The annulus fibrosus differentiated into lateral and medial zones. Within the lateral zone cells were arranged into circular rows. These rows were considered as the first stage of laminar structure. In further developmental stages the laminae occupied both zones of the annulus fibrosus.Conclusions. The intervertebral discs develop from the dense zone of the sclerotome which is evident in embryos at stage 13 (32 days). Discs differentiate in embryos aged 33 days, when the nucleus pulposus and annulus fibrosus are recognized. In embryos aged 36 days in the annulus fibrosus circular rows forming laminar arrangement are seen.

Osmo-inelastic response of the intervertebral disc annulus fibrosus tissue

2020 ◽  
Vol 234 (9) ◽  
pp. 1000-1010
Author(s):  
Amil Derrouiche ◽  
Ameni Zaouali ◽  
Fahmi Zaïri ◽  
Jewan Ismail ◽  
Zhengwei Qu ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Mechanical Response ◽  
Rate Sensitivity ◽  
Image Correlation ◽  
Inelastic Response ◽  
Full Field ◽  
Osmotic Effect ◽  
Rate Dependent ◽  
Optical Strain

The aim of this article is to provide some insights on the osmo-inelastic response under stretching of annulus fibrosus of the intervertebral disc. Circumferentially oriented specimens of square cross section, extracted from different regions of bovine cervical discs (ventral-lateral and dorsal-lateral), are tested under different strain-rates and saline concentrations within normal range of strains. An accurate optical strain measuring technique, based upon digital image correlation, is used in order to determine the full-field displacements in the lamellae and fibers planes of the layered soft tissue. Annulus stress–stretch relationships are measured along with full-field transversal strains in the two planes. The mechanical response is found hysteretic, rate-dependent and osmolarity-dependent with a Poisson’s ratio higher than 0.5 in the fibers plane and negative (auxeticity) in the lamellae plane. While the stiffness presents a regional-dependency due to variations in collagen fibers content/orientation, the strain-rate sensitivity of the response is found independent on the region. A significant osmotic effect is found on both the auxetic response in the lamellae plane and the stiffness rate-sensitivity. These local experimental observations will result in more accurate chemo-mechanical modeling of the disc annulus and a clearer multi-scale understanding of the disc intervertebral function.

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