INGROWTH OF NEURAL ELEMENTS INTO THE ANNULUS FIBROSUS OF OVINE INTERVERTEBRAL DISC IN AN ACUTE AND SUBACUTE EXPERIMENTAL DISC INJURY

2003 ◽  
Vol 07 (01) ◽  
pp. 39-47
Author(s):  
A. K. Lappalainen ◽  
E. Kääpä ◽  
M. Grönblad
Keyword(s):  
Schwann Cell ◽  
Intervertebral Disc ◽  
Blood Vessels ◽  
Schwann Cells ◽  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Acute Injury ◽  
Blood Capillaries ◽  
Pgp 9.5 ◽  
Experimentally Induced

Ingrowth of nerves and blood vessels is regarded as a part of disc degeneration. Schwann cells, which guide the development and regeneration of nerves both in the central and peripheral nervous system, have recently been located in degenerated human discs. The purpose of this study was to investigate by immunohistochemical methods, whether or not there was nerve, Schwann cell and blood vessel ingrowth in experimentally induced acute (3 weeks) and subacute (3 months) annular tears; and to study the detailed topography of such nerve ingrowth when present. Ingrowth of nerves and Schwann cells has so far not been studied in experimentally induced acute annular tears. A stab incision with a scalpel blade was made in two adjacent lumbar discs in adult sheep (n = 9). The L2–L3 discs were injured superficially, whereas in L3–L4 discs the incision reached the nucleus pulposus (full-thickness injury). The animals were sacrificed three weeks (acute injury, n = 3) or three months (subacute injury, n = 6) post-operatively. Discs were immunoassayed for general neuronal markers (protein gene product 9.5, PGP 9.5 and synaptophysin, SYN), Schwann cell marker (glial fibrillary acidic protein, GFAP) and endothelial marker (CD 31). Nerves visualized with all antibodies employed were situated inside the injured area and mainly near amd around blood vessels although free nerve endings could be seen also. PGP 9.5-immunopositive nerves were evident in every sample. Immunoreactivity to SYN and GFAP was not observed in control discs. Such immunoreactivity appeared already at 3 weeks (acute injury) in a few samples, and was present in all samples at 3 months (subacute injury). For the superficial injury, nerves did not penetrate deeper than in control discs until at 3 months. With more extensive annular injury, mean values for both nerve and Schwann cell penetration were higher. Blood capillaries were visible deeper in the inner annulus than neural tissues immunopositive to PGP 9.5, GFAP or SYN. The results suggest an ingrowth of nerves and Schwann cells with time, following an injury of the annulus fibrosus. A trend for deeper penetration already in the acute stage, but only for deep lesions reaching all the way to the nucleus pulposus, may be suggested. Such ingrowth, also previously reported in degenerated human discs, may relate to mechanisms of low back pain, originating in the intervertebral disc.

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.

Isolation of Nucleus Pulposus and Annulus Fibrosus Cells from the Intervertebral Disc

2020 ◽  
pp. 41-52
Author(s):  
Guus G. H. van den Akker ◽  
Andy Cremers ◽  
Donatus A. M. Surtel ◽  
Willem Voncken ◽  
Tim J. M. Welting
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Annulus Fibrosus

Effects of Swelling Conditions on the Compressive Properties of Nucleus Pulposus From Bovine Intervertebral Discs

2004 ◽  
Author(s):  
David T. Korda ◽  
Delphine Perie ◽  
James C. Iatridis
Keyword(s):  
Intervertebral Disc ◽  
Water Content ◽  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Compressive Loading ◽  
Collagen Matrix ◽  
High Water ◽  
Intervertebral Discs ◽  
High Water Content ◽  
Outer Annulus Fibrosus

The intervertebral disc provides flexibility and load support for the spine. It consists of two main regions; the outer annulus fibrosus which is a highly organized collagen matrix and the inner nucleus pulposus which (in a healthy disc) is a proteoglycan rich gelatinous material. The predominant mode of loading on the intervertebral disc is axial compression, which generates hydrostatic pressures within the disc. The high water content of the nucleus plays a major role in supporting these loads. With age and degeneration, the water content of the nucleus changes, and is believed to significantly impact its ability to bear load. The purpose of this study therefore, was to define the effects of swelling conditions (which affect disc hydration) on the material properties of the disc under compressive loading.

Reactive changes in the adolescent porcine spine with disc degeneration due to endplate injury

2007 ◽  
Vol 20 (01) ◽  
pp. 12-17 ◽  
Author(s):  
A. Baranto ◽  
A. Kaigle Holm ◽  
L. Ekström ◽  
L. Swärd ◽  
T. Hansson ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Scar Tissue ◽  
Vertebral Endplate ◽  
Lumbar Intervertebral Disc ◽  
Physiological Loading ◽  
Reactive Changes ◽  
Chronic Inflammatory Reaction

SummaryDegenerative and reactive structural alterations occurring after experimentally-induced disc degeneration were evaluated using a porcine model. A cranial perforation was made through the L4 vertebral endplate into the nucleus pulposus. Three months later, the lumbar intervertebral disc and adjacent vertebrae were dissected, fixed in formalin and further processed for histopathological analyses. The results showed that there were nucleus pulposus fragments, rather than a distinct border between the nucleus and annulus fibrosus. The central lamellae were distorted and delamination of the outer anterior layers was observed. Blood vessels emerged from the adjacent tissue, penetrated the annulus and branched into the residues of the nucleus. Nerve fibres accompanying the blood vessels could be recognized in the disc within the connective scar tissue. The epiphyseal cartilage plates in the vertebrae were hypertrophic in several areas and there was bone formation directed towards the centre of the vertebral body and the disc. Hypertrophic hyaline cartilage, newly formed bone and scar tissue filled the injury canal. A slight chronic inflammatory reaction was evident along vascular buds. The reactive changes dominated over the degenerated features in the operated disc. Physiological loading enhanced the infiltration of various tissue types characterizing immature cartilage formation. Prominent neovascularisation of the central parts of the disc is likely to be of key importance in turning the degenerative features of the remaining tissue into reactive healthy structures.

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

2021 ◽  
Author(s):  
Audrey McAlinden ◽  
David M Hudson ◽  
Aysel A Fernandes ◽  
Soumya Ravindran ◽  
Russell J Fernandes
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Small Diameter ◽  
Type Ii Collagen ◽  
Intervertebral Discs ◽  
Matrix Composition ◽  
Type I ◽  
Type Ii ◽  
Post Translational Modification

For next generation tissue-engineered constructs and regenerative medicine to succeed clinically, the basic biology and extracellular matrix composition of tissues that these repair techniques seek to restore have to be fully determined. Using the latest reagents coupled with tried and tested methodologies, we continue to uncover previously undetected structural proteins in mature intervertebral disc. In this study we show that the ″embryonic″ type IIA procollagen isoform (containing a cysteine-rich amino propeptide) was biochemically detectable in the annulus fibrosus of both calf and mature steer intervertebral discs, but not in the nucleus pulposus where the type IIB isoform was predominantly localized. Specifically, the triple-helical type IIA procollagen isoform immunolocalized in the outer margins of the inner annulus fibrosus. Triple helical processed type II collagen exclusively localized within the inter- lamellae regions and with type IIA procollagen in the intra-lamellae regions. Mass spectrometry of the a1(II) collagen chains from the region where type IIA procollagen localized showed high 3-hydroxylation of Proline-944, a post- translational modification that is correlated with thin collagen fibrils as in the nucleus pulposus. The findings implicate small diameter fibrils of type IIA procollagen in select regions of the annulus fibrosus where it likely contributes to the organization of collagen bundles and structural properties within the type I- type II collagen transition zone.

scholarly journals Contrast-enhanced microCT evaluation of degeneration following partial and full width injuries to mouse lumbar intervertebral disc

2022 ◽  
Author(s):  
Remy E Walk ◽  
Hong Joo Moon ◽  
Simon Y Tang ◽  
Munish C Gupta
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Annulus Fibrosus ◽  
Partial Width ◽  
Full Width ◽  
Lumbar Intervertebral Disc ◽  
Study Objective ◽  
Post Surgery ◽  
Contrast Enhanced ◽  
Ivd Degeneration

Study Design: Preclinical animal study. Objective: Evaluation of the degenerative progression resulting from either a partial- or full- width injury to the mouse lumbar intervertebral disc (IVD) using contrast-enhanced micro-computed tomography and histological analyses. We utilized a lateral-retroperitoneal surgical approach to access the lumbar IVD, and the injuries to the IVD were induced by either incising one side of the annulus fibrosus or puncturing both sides of the annulus fibrosus. The full-width injury caused dramatic reduction in nucleus pulposus hydration and significant degeneration. A partial-width injury produces localized deterioration around the annulus fibrosus site that resulted in local tissue remodeling without gross degeneration to the IVD. Methods: Female C57BL/6J mice of 3-4 months age were used in this study. They were divided into three groups to undergo a partial-width, full-width, or sham injuries. The L5/L6 and L6/S1 lumbar IVDs were surgically exposed using a lateral-retroperitoneal approach. The L6/S1 IVDs were injured using either a surgical scalpel (partial-width) or a 33G needle (full-width), with the L5/L6 serving as an internal control. These animals were allowed to recover and then sacrificed at 2-, 4-, or 8- weeks post-surgery. The IVDs were assessed for degeneration using contrast-enhanced microCT (CEμCT) and histological analysis. Results: The high-resolution 3D evaluation of the IVD confirmed that the respective injuries localized within one side of the annulus fibrosus or spanned the full width of the IVD. The full-width injury caused deteriorations in the nucleus pulposus after 2 weeks that culminated in significant degeneration at 8 weeks, while the partial width injury caused localized disruptions that remained limited to the annulus fibrosus. Conclusion: The use of CEμCT revealed distinct IVD degeneration profiles resulting from partial- and full- width injuries. The partial width injury may serve as a better model for IVD degeneration resulting from localized annulus fibrosus injuries in humans.

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