A Removable Precision Device for In-Vivo Mechanical Compression of Rat Tail Intervertebral Discs

2006 ◽  
Vol 1 (1) ◽  
pp. 56-61 ◽  
Author(s):  
Justin M. Stinnett-Donnelly ◽  
Jeffrey J. MacLean ◽  
James C. Iatridis
Keyword(s):  
Intervertebral Disc ◽  
Compressive Loading ◽  
Cost Effective ◽  
Intervertebral Discs ◽  
Modular Construction ◽  
New Device ◽  
Loading System ◽  
Compressive Loads ◽  
Rat Tail

The rat tail intervertebral disc has emerged as an important model to examine the mechanisms for mechanically induced degeneration and remodeling. Previous methods used to apply high precision axial compressive loading to a rat tail intervertebral disc in vivo either required anesthesia, or the permanent mounting of a loading device to the animal, and were not well described in the literature. Therefore, a new device to apply compressive loading to the rat tail intervertebral disc was developed and validated. The rat tail compressive loading system utilized a pneumatically driven device weighing 18g, and was capable of delivering a 12.6N sinusoidal or square waveform at frequencies up to 1.0Hz. The system improved on previous methods in its modular construction, relative ease of fabrication, compatibility with existing tail model technology and overall cost effectiveness. The removable system eliminated the need for anesthesia and through a modular, cost effective, design allowed for the simultaneous loading of multiple animals. This system expanded the ability to accurately, ethically, and efficiently apply dynamic compressive loads to the rat tail intervertebral disc for extended periods of time in order to address questions related to disc mechanobiology.

scholarly journals Tissue Modification of the Lateral Compartment of the Tibio-Femoral Joint Following In Vivo Varus Loading in the Rat

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
M. L. Roemhildt ◽  
B. D. Beynnon ◽  
M. Gardner-Morse ◽  
K. Anderson ◽  
G. J. Badger
Keyword(s):  
Articular Cartilage ◽  
Subchondral Bone ◽  
Compressive Loading ◽  
Compressive Load ◽  
Lateral Compartment ◽  
Peripheral Region ◽  
Degenerative Changes ◽  
Medial Compartment ◽  
Compressive Loads

This study describes the first application of a varus loading device (VLD) to the rat hind limb to study the role of sustained altered compressive loading and its relationship to the initiation of degenerative changes to the tibio-femoral joint. The VLD applies decreased compressive load to the lateral compartment and increased compressive load to the medial compartment of the tibio-femoral joint in a controlled manner. Mature rats were randomized into one of three groups: unoperated control, 0% (sham), or 80% body weight (BW). Devices were attached to an animal’s leg to deliver altered loads of 0% and 80% BW to the experimental knee for 12 weeks. Compartment-specific material properties of the tibial cartilage and subchondral bone were determined using indentation tests. Articular cartilage, calcified cartilage, and subchondral bone thicknesses, articular cartilage cellularity, and degeneration score were determined histologically. Joint tissues were sensitive to 12 weeks of decreased compressive loading in the lateral compartment with articular cartilage thickness decreased in the peripheral region, subchondral bone thickness increased, and cellularity of the midline region decreased in the 80% BW group as compared to the 0% BW group. The medial compartment revealed trends for diminished cellularity and aggregate modulus with increased loading. The rat-VLD model provides a new system to evaluate altered quantified levels of chronic in vivo loading without disruption of the joint capsule while maintaining full use of the knee. These results reveal a greater sensitivity of tissue parameters to decreased loading versus increased loading of 80% BW for 12 weeks in the rat. This model will allow future mechanistic studies that focus on the initiation and progression of degenerative changes with increased exposure in both magnitude and time to altered compressive loads.

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.

Reliability of radiographic intervertebral disc height measurement for in vivo rat-tail model

2007 ◽  
Vol 29 (7) ◽  
pp. 814-819 ◽  
Author(s):  
Alon Lai ◽  
Daniel H.K. Chow ◽  
W.S. Siu ◽  
Andrew D. Holmes ◽  
F.H. Tang
Keyword(s):  
Intervertebral Disc ◽  
Disc Height ◽  
Height Measurement ◽  
Intervertebral Disc Height ◽  
Rat Tail Model ◽  
Rat Tail

The Knee Loading Apparatus: Axial, Anterior, and Compressive Loading With Magnetic Resonance Imaging

2013 ◽  
Vol 135 (2) ◽  
Author(s):  
Jessica C. Küpper ◽  
Ion Robu ◽  
Richard Frayne ◽  
Janet L. Ronsky
Keyword(s):  
Magnetic Resonance ◽  
Knee Joint ◽  
Weight Bearing ◽  
Compressive Loading ◽  
Hydraulic Loading ◽  
Additional Information ◽  
Knee Loading ◽  
Loading System ◽  
Main Components

When magnetic resonance (MR) images are collected while applying a load to the knee joint, additional information about the joint response to loading can be acquired such as cartilage deformation, whole joint and ligament stiffness, or physiological estimates of weight-bearing joint positions. To allow load application and controlled lower limb movement in supine MR imaging, the knee loading apparatus (KLA) was designed to apply safe and physiologically relevant controlled loads to the knee joint, position the knee through a range of flexion angles, and operate successfully in a magnetic environment. The KLA is composed of three main components: a remotely operated custom hydraulic loading system, a logic system that interfaces with the user, and modular non ferromagnetic positioning frames. Three positioning frames are presented for application to anterior tibial loading, tibiofemoral compression, and patellofemoral compression at multiple knee flexion angles. This system design makes improvements over current devices. Safe remotely applied loads (hydraulic loading system) can be applied by either subject or tester and in multiple locations simultaneously. Additionally, loads can be altered at any time in a continuous manner without electrical interference. Transportability was improved due to a smaller footprint. The KLA has the flexibility to attach any positioning frame with many possible loading scenarios without changing the loading mechanism or logic systems, and allows force values over time to be output rather than estimated. An evaluation of the load repeatability (within 7% of applied load) and accuracy (0.5–14.9%) demonstrates the feasibility of this design for investigations into in vivo knee joint responses to loading.

scholarly journals Propionibacterium acnes Induces Intervertebral Disc Degeneration by Promoting iNOS/NO and COX-2/PGE2 Activation via the ROS-Dependent NF-κB Pathway

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Yazhou Lin ◽  
Guoqing Tang ◽  
Yucheng Jiao ◽  
Ye Yuan ◽  
Yuehuan Zheng ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Intervertebral Disc Degeneration ◽  
Propionibacterium Acnes ◽  
Intervertebral Discs ◽  
Cox 2 ◽  
Underlying Mechanisms

Accumulating evidence suggests that Propionibacterium acnes (P. acnes) is a novel pathogenic factor promoting intervertebral disc degeneration (IVDD). However, the underlying mechanisms by which P. acnes induces IVDD have been unclear. In this study, we quantified the severity of IVDD, as well as the expressions of inducible nitric oxide synthase (iNOS)/nitric oxide (NO) and cyclooxygenase (COX-2)/prostaglandin (PGE2) in human intervertebral discs (IVDs) infected with P. acnes. Compared with P. acnes-negative IVDs, P. acnes-positive IVDs showed increased iNOS/NO and COX-2/PGE2 activity concomitant with more severe IVDD. In order to detect the potential correlation between iNOS/NO expression, COX-2/PGE2 expression, and IVDD, we developed a P. acnes-induced IVDD rat model and found that the upregulation of iNOS/NO and COX-2/PGE2 was essential to the occurrence of P. acnes-induced IVDD. This finding was supported by the fact that the inhibition of iNOS/NO and COX-2/PGE2 activity ameliorated IVDD significantly, as evidenced by restored aggrecan and collagen II expression both in vivo and in vitro. Mechanistically, we found that P. acnes induced iNOS/NO and COX-2/PGE2 expressions via a reactive oxygen species- (ROS-) dependent NF-κB cascade. Furthermore, NADPH oxidase participated in P. acnes-induced ROS, iNOS/NO, and COX-2/PGE2 expressions. Overall, these findings further validated the involvement of P. acnes in the pathology of IVDD and provided evidence that P. acnes-induced iNOS/NO and COX-2/PGE2 activation via the ROS-dependent NF-κB pathway is likely responsible for the pathology of IVDD.

scholarly journals Giraffes and hominins: reductionist model predictions of compressive loads at the spine base for erect exponents of the animal kingdom

Biology Open ◽  
2020 ◽  
pp. bio.057224
Author(s):  
Michael Günther ◽  
Falk Mörl
Keyword(s):  
Compressive Stress ◽  
Intervertebral Discs ◽  
Intradiscal Pressure ◽  
Pressure Data ◽  
Animal Kingdom ◽  
Model Predictions ◽  
Compressive Loads ◽  
Spine Model ◽  
Pulling Force

In humans, compressive stress on intervertebral discs is commonly deployed as a measurand for assessing the loads that act within the spine. Examining this physical quantity is crucially beneficial: the intradiscal pressure can be directly measured in vivo in humans, and is immediately related to compressive stress. Hence, measured intradiscal pressure data are utterly useful for validating such biomechanical animal models that have the spine incorporated, and can, thus, compute compressive stress values. Here, we utilise human intradiscal pressure data to verify the predictions of a reductionist spine model, which has in fact only one joint degree of freedom. We calculate the pulling force of one lumped anatomical structure that acts past this (intervertebral) joint at the base of the spine—lumbar in hominins, cervical in giraffes—to compensate the torque that is induced by the weight of all masses located cranially to the base. Given morphometric estimates of the human and australopith trunks, respectively, and the giraffe's neck, as well as the respective structures’ lever arms and disc areas, we predict, for all three species, the compressive stress on the intervertebral disc at the spine base, while systematically varying the angular orientation of the species’ spinal columns with respect to gravity. The comparison between these species demonstrates that hominin everyday compressive disc stresses are lower than such in big quadrupedal animals. Within each species, erecting the spine from being bent forward by, for example, thirty degrees to fully upright posture reduces the compressive disc stress roughly to a third. We conclude that erecting the spine immediately allows to carry extra loads of the order of body weight, and yet the compressive disc stress is lower than in a moderately forward-bent posture with none extra load.

Frequency of unexpected and important histopathological findings in routine intervertebral disc surgery

2006 ◽  
Vol 4 (1) ◽  
pp. 20-23 ◽  
Author(s):  
Martin Hasselblatt ◽  
David Maintz ◽  
Thomas Goll ◽  
Uwe Wildförster ◽  
Christoph Schul ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Cell Lymphoma ◽  
Histopathological Examination ◽  
B Cell Lymphoma ◽  
Cost Effective ◽  
Intervertebral Discs ◽  
Histopathological Findings ◽  
Large B Cell Lymphoma ◽  
Disc Surgery ◽  
Retrospective Examination

Object The value of routine histopathological examination of intervertebral disc tissue has been questioned, but sufficient numbers of studies have yet to be conducted to provide a definitive sense of its importance. The aim of this study was to investigate the nature and frequency of unexpected histopathological findings in intervertebral disc surgery. Methods The authors conducted a retrospective examination of consecutive surgical specimens obtained in patients with benign indication for discectomy at four neurosurgical centers. Surgical specimens obtained during 2102 operations (2177 intervertebral discs) in 2017 patients were evaluated. In addition to one case of cavernous malformation, two specimens (obtained in 0.1% of patients) revealed unexpected pathological diagnoses of malignancy (metastasized prostate carcinoma and diffuse large B-cell lymphoma). Conclusions The results of this retrospective study suggest that routine histopathological examination of specimens obtained during intervertebral disc procedures is both justified and cost effective.

Effects of electroacupuncture on a degenerated intervertebral disc using an in-vivo rat-tail model

2008 ◽  
Vol 222 (2) ◽  
pp. 241-248 ◽  
Author(s):  
A Lai ◽  
D H K Chow ◽  
W-S Siu ◽  
A D Holmes ◽  
F-H Tang ◽  
...  
Keyword(s):  
Back Pain ◽  
Intervertebral Disc ◽  
Disc Degeneration ◽  
Biological Properties ◽  
Disc Height ◽  
Static Compression ◽  
Intervertebral Disc Height ◽  
Rat Tail Model ◽  
Rat Tail

Electroacupuncture (EA) has long been used as conservative treatment for low back pain (LBP). Its effect on relief of back pain has been demonstrated in many clinical studies. However, whether it has any effect on the biological properties of an intervertebral disc, which is one of the major causes of LBP, is still unclear. The aim of this study was, therefore, to investigate the effects of EA with different simulation frequencies on an intervertebral disc with simulated degeneration using an in-vivo rat-tail model. In this study, 33 rats were used. Disc degeneration was simulated in the rat caudal 8—9 disc via continuous static compressive loading of 11 N for 2 weeks. EA with a frequency of 2 or 100 Hz was then applied to the degenerated disc for 3 weeks with 3 sessions/week and 20 min/session. The intervertebral disc height was measured before and after compression as well as after EA intervention for 3 weeks. The static compression was found to result in a reduction in the disc height of about 22 per cent. There was no evidence that this change could be reversed after resting or the EA intervention. However, EA at 100 Hz was found to induce a further decrease in disc height, which was not shown for the rats after resting or EA at 2 Hz. The results of this study showed that effects of EA on disc degeneration are frequency dependent and adverse effects could result if EA at a certain frequency was used.

scholarly journals Repetitive in vivo manual loading of the spine elicits cellular responses in porcine annuli fibrosi

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248104
Author(s):  
John Robert Matyas ◽  
Claudia Klein ◽  
Dragana Ponjevic ◽  
Neil A. Duncan ◽  
Gregory N. Kawchuk
Keyword(s):  
Intervertebral Disc ◽  
Manual Therapy ◽  
Cellular Response ◽  
Cell Metabolism ◽  
Low Frequency ◽  
Intervertebral Discs ◽  
Disc Cell ◽  
Therapy Interventions ◽  
Pathway Analyses

Back pain and intervertebral disc degeneration are prevalent, costly, and widely treated by manual therapies, yet the underlying causes of these diseases are indeterminate as are the scientific bases for such treatments. The present studies characterize the effects of repetitive in vivo manual loads on porcine intervertebral disc cell metabolism using RNA deep sequencing. A single session of repetitive manual loading applied to the lumbar spine induced both up- and down-regulation of a variety of genes transcribed by cells in the ventral annuli fibrosi. The effect of manual therapy at the level of loading was greater than at a level distant to the applied load. Gene ontology and molecular pathway analyses categorized biological, molecular, and cellular functions influenced by repetitive manual loading, with over-representation of membrane, transmembrane, and pericellular activities. Weighted Gene Co-expression Network Analysis discerned enrichment in genes in pathways of inflammation and skeletogenesis. The present studies support previous findings of intervertebral disc cell mechanotransduction, and are the first to report comprehensively on the repertoire of gene targets influenced by mechanical loads associated with manual therapy interventions. The present study defines the cellular response of repeated, low-amplitude loads on normal healthy annuli fibrosi and lays the foundation for future work defining how healthy and diseased intervertebral discs respond to single or low-frequency manual loads typical of those applied clinically.

Sign in / Sign up

Export Citation Format

Share Document