Effects of laser irradiation on collagen organization in chemically induced degenerative annulus fibrosus of lumbar intervertebral disc

2008 ◽  
Vol 40 (6) ◽  
pp. 422-432 ◽  
Author(s):  
Natalia Ignatieva ◽  
Olga Zakharkina ◽  
Irina Andreeva ◽  
Emil Sobol ◽  
Vladislav Kamensky ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Laser Irradiation ◽  
Annulus Fibrosus ◽  
Lumbar Intervertebral Disc ◽  
Collagen Organization ◽  
Chemically Induced

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.

The Mechanical Role of the Radial Fiber Network Within the Annulus Fibrosus of the Lumbar Intervertebral Disc: A Finite Elements Study

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Mirit Sharabi ◽  
Aviad Levi-Sasson ◽  
Roza Wolfson ◽  
Kelly R. Wade ◽  
Fabio Galbusera ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Local Stress ◽  
Element Model ◽  
Collagen Fibers ◽  
Lumbar Intervertebral Disc ◽  
Fiber Network ◽  
Radial Fiber ◽  
The Matrix

The annulus fibrosus (AF) of the intervertebral disc (IVD) consists of a set of concentric layers composed of a primary circumferential collagen fibers arranged in an alternating oblique orientation. Moreover, there exists an additional secondary set of radial translamellar collagen fibers which connects the concentric layers, creating an interconnected fiber network. The aim of this study was to investigate the mechanical role of the radial fiber network. Toward that goal, a three-dimensional (3D) finite element model of the L3–L4 spinal segment was generated and calibrated to axial compression and pure moment loading. The AF model explicitly recognizes the two heterogeneous networks of fibers. The presence of radial fibers demonstrated a pronounced effect on the local disc responses under lateral bending, flexion, and extension modes. In these modes, the radial fibers were in a tensile state in the disc region that subjected to compression. In addition, the circumferential fibers, on the opposite side of the IVD, were also under tension. The local stress in the matrix was decreased in up to 9% in the radial fibers presence. This implies an active fiber network acting collectively to reduce the stresses and strains in the AF lamellae. Moreover, a reduction of 26.6% in the matrix sideways expansion was seen in the presence of the radial fibers near the neutral bending axis of the disc. The proposed biomechanical model provided a new insight into the mechanical role of the radial collagen fibers in the AF structure. This model can assist in the design of future IVD substitutes.

scholarly journals Application study of 3D LAVA-Flex on lumbar intervertebral disc degeneration

2021 ◽  
Vol 26 (1) ◽  
Author(s):  
Tiefang Liu ◽  
Yonghao Wang ◽  
Zhengyang Xu ◽  
Tao Wu ◽  
Xiao Zang ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Nucleus Pulposus ◽  
Disc Degeneration ◽  
Annulus Fibrosus ◽  
Intervertebral Disc Degeneration ◽  
Virtual Endoscopy ◽  
Intervertebral Space ◽  
Lumbar Intervertebral Disc ◽  
Component Structure ◽  
Pfirrmann Grade

Abstract Background Degeneration of the intervertebral discs are very common diseases, indicating the specific or malignant changes in intervertebral disc component, structure and function. Imaging examination is currently used to evaluate the severity of lumbar intervertebral disc degeneration. This study was designed to investigate the diagnostic value of 3D LAVA-Flex in lumbar intervertebral disc degeneration. Material and methods Sagittal 3D LAVA-Flex and T2WI scans were performed in 45 patients with lumbar intervertebral disc degeneration. On T2WI, the degenerated intervertebral disc in every patient was evaluated using Pfirrmann grade. Then, the patients were re-evaluated using 3D LAVA-Flex with considerations of the distinction of nucleus pulposus and annulus fibrosus, hypointense signal of intervertebral disc and height of intervertebral disc. The evaluation results were compared between 3D LAVA-Flex and T2WI. Virtual endoscopy was also performed to evaluate the degenerated intervertebral disc. Results The intermediate–intense signal of nucleus pulposus and complete ring-shaped hyperintense signal of annulus fibrosus were found and the distinction of nucleus pulposus and annulus fibrosus was clear in the normal intervertebral disc on 3D LAVA-Flex. The incidence of linear hypointensity of narrowed intervertebral space (65/91) was higher than that of normal intervertebral space (4/134) (P = 0.000). A good consistency was shown between the LAVA-Flex grade and T2WI-based Pfirrmann grade. Virtual endoscopy based on 3D LAVA-Flex could help clearly show the anatomic relationship between the degenerated disc and intervertebral foramen. Conclusions 3D LAVA-Flex and T2WI show similar efficacy in evaluating lumbar intervertebral disc degeneration. 3D LAVA-Flex-based virtual endoscopy possesses great potential in the study of intervertebral disc abnormalities.

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.

Sign in / Sign up

Export Citation Format

Share Document