Changes in Intervertebral Disk Mechanical Behavior During Early Degeneration

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Cornelis P. L. Paul ◽  
Kaj S. Emanuel ◽  
Idsart Kingma ◽  
Albert J. van der Veen ◽  
Roderick M. Holewijn ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Intervertebral Disk ◽  
Exponential Fitting ◽  
Stretched Exponential ◽  
Disk Degeneration ◽  
Histological Sections ◽  
Biomechanical Behavior ◽  
Recovery Behavior ◽  
Ivd Degeneration ◽  
Disk Height

Intervertebral disk (IVD) degeneration is commonly described by loss of height and hydration. However, in the first stage of IVD degeneration, this loss has not yet occurred. In the current study, we use an ex vivo degeneration model to analyze the changes in IVDs mechanical behavior in the first phase of degeneration. We characterize these changes by stretched-exponential fitting, and suggest the fitted parameters as markers for early degeneration. Enzymatic degeneration of healthy lumbar caprine IVDs was induced by injecting 100 μL of Chondroïtinase ABC (Cabc) into the nucleus. A no-intervention and phosphate buffered saline (PBS) injected group were used as controls. IVDs were cultured in a bioreactor for 20 days under diurnal, simulated-physiological loading (SPL) conditions. Disk deformation was continuously monitored. Changes in disk height recovery behavior were quantified using stretched-exponential fitting. Disk height, histological sections, and water- and glycosaminoglycan (GAG)-content measurements were used as gold standards for the degenerative state. Cabc injection caused significant GAG loss from the nucleus and had detrimental effects on poro-elastic mechanical properties of the IVDs. These were progressive over time, with a propensity toward more linear recovery behavior. On histological sections, both PBS and Cabc injected IVDs showed moderate degeneration. A small GAG loss yields changes in IVD recovery behavior, which can be quantified with stretched-exponential fitting. Parameters changed significantly compared to control. Studies on disk degeneration and biomaterial engineering for degenerative disk disease (DDD) could benefit from focusing on IVD biomechanical behavior rather than height and water-content, as a marker for early disk degeneration.

scholarly journals Melatonin Attenuates Intervertebral Disk Degeneration via Maintaining Cartilaginous Endplate Integrity in Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiexing Wu ◽  
Yijie Liu ◽  
Jiacheng Du ◽  
Xiaoping Li ◽  
Jiayi Lin ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Intervertebral Disk ◽  
Control Group ◽  
Nuclear Factor ◽  
Matrix Degradation ◽  
Potential Mechanism ◽  
Intervertebral Disk Degeneration ◽  
Disk Degeneration ◽  
Disk Height

ObjectiveThe aim of this study is to verify whether melatonin (Mel) could mitigate intervertebral disk degeneration (IVDD) in rats and to investigate the potential mechanism of it.MethodA rat acupuncture model of IVDD was established with intraperitoneal injection of Mel. The effect of Mel on IVDD was analyzed via radiologic and histological evaluations. The specific Mel receptors were investigated in both the nucleus pulposus (NP) and cartilaginous endplates (EPs). In vitro, EP cartilaginous cells (EPCs) were treated by different concentrations of Mel under lipopolysaccharide (LPS) and Luzindole conditions. In addition, LPS-induced inflammatory response and matrix degradation following nuclear factor kappa-B (NF-κB) pathway activation were investigated to confirm the potential mechanism of Mel on EPCs.ResultsThe percent disk height index (%DHI) and MRI signal decreased after initial puncture in the degeneration group compared with the control group, while Mel treatment protected disk height from decline and prevented the loss of water during the degeneration process. In the meantime, the histological staining of the Mel groups showed more integrity and well-ordered construction of the NP and EPs in both low and high concentration than that of the degeneration group. In addition, more deep-brown staining of type II collagen (Coll-II) was shown in the Mel groups compared with the degeneration group. Furthermore, in rat samples, immunohistochemical staining showed more positive cells of Mel receptors 1a and 1b in the EPs, instead of in the NP. Moreover, evident osteochondral lacuna formation was observed in rat EPs in the degeneration group; after Mel treatment, the osteochondral destruction alleviated accompanying fewer receptor activator for nuclear factor-κB ligand (RANKL) and tartrate-resistant acid phosphatase (TRAP)-stained positive cells expressed in the EPs. In vitro, Mel could promote the proliferation of EPCs, which protected EPCs from degeneration under LPS treatment. What is more, Mel downregulated the inflammatory response and matrix degradation of EPCs activated by NF-κB pathway through binding to its specific receptors.ConclusionThese results indicate that Mel protects the integrity of the EPs and attenuates IVDD by binding to the Mel receptors in the EPs. It may alleviate the inflammatory response and matrix degradation of EPCs activated by NF-κB pathway.

Ultrashort Time-to-Echo MRI of the Cartilaginous Endplate: Technique and Association with Intervertebral Disk Degeneration

2012 ◽  
Vol 2 (1_suppl) ◽  
pp. s-0032-1319972-s-0032-1319972
Author(s):  
T. Law ◽  
M. P. Anthony ◽  
D. Samartzis ◽  
Q. Chan ◽  
M. Kim ◽  
...  
Keyword(s):  
Intervertebral Disk ◽  
Intervertebral Disk Degeneration ◽  
Disk Degeneration ◽  
Cartilaginous Endplate

Combination of MRI and 99mTc-NTP 15-5 Scintigraphy for the Assessment of Intervertebral Disk Degeneration and Tissue Engineering

2012 ◽  
Vol 2 (1_suppl) ◽  
pp. s-0032-1319873-s-0032-1319873
Author(s):  
P. Colombier ◽  
J. Clouet ◽  
E. Miot-Noirault ◽  
A. Vidal ◽  
F. Cachin ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Intervertebral Disk ◽  
Intervertebral Disk Degeneration ◽  
Disk Degeneration

scholarly journals Raloxifene retards the progression of adjacent segmental intervertebral disc degeneration by inhibiting apoptosis of nucleus pulposus in ovariectomized rats

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Qi Sun ◽  
Xin-Yu Nan ◽  
Fa-Ming Tian ◽  
Fang Liu ◽  
Shao-Hua Ping ◽  
...  
Keyword(s):  
Nucleus Pulposus ◽  
Lumbar Fusion ◽  
B Cell Lymphoma ◽  
Intervertebral Disk ◽  
Ovariectomized Rats ◽  
Tunel Staining ◽  
Mineral Density ◽  
Vertebral Osteoporosis ◽  
Intervertebral Disk Degeneration ◽  
Disk Degeneration

Abstract Background Adjacent segmental intervertebral disk degeneration (ASDD) is a major complication secondary to lumbar fusion. Although ASSD pathogenesis remains unclear, the primary cause of intervertebral disk degeneration (IVDD) development is apoptosis of nucleus pulposus (NP). Raloxifene (RAL) could delay ASDD by inhibiting NP apoptosis. Methods An ASDD rat model was established by ovariectomy (OVX) and posterolateral spinal fusion (PLF) on levels 4–5 of the lumbar vertebrae. Rats in the treatment groups were administered 1 mg/kg/d RAL by gavage for 12 weeks, following which, all animals were euthanized. Lumbar fusion, apoptosis, ASDD, and vertebrae micro-architecture were evaluated. Results RAL maintained intervertebral disk height (DHI), delayed vertebral osteoporosis, reduced histological score, and inhibited apoptosis. The OVX+PLF+RAL group revealed upregulated expression of aggrecan and B-cell lymphoma-2 (bcl2), as well as significantly downregulated expression of a disintegrin and metalloproteinase with thrombospondin motifs 4 (ADAMTS-4), metalloproteinase-13 (MMP-13), caspase-3, BCL2-associated X (bax), and transferase dUTP nick end labeling (TUNEL) staining. Micro-computed tomography (Micro-CT) analysis revealed higher bone volume fraction (BV/TV), bone mineral density (BMD), and trabecular number (Tb.N), and lower trabecular separation (Tb.Sp) in OVX+PLF+RAL group than in the OVX+PLF group. Conclusions RAL can postpone ASDD development in OVX rats through inhibiting extracellular matrix metabolic imbalance, NP cell apoptosis, and vertebral osteoporosis. These findings showed RAL as a potential therapeutic target for ASDD.

Biomechanical Behavior of All-Ceramic Crowns with Variable Thicknesses of Zirconia Frameworks

2016 ◽  
Vol 835 ◽  
pp. 97-102
Author(s):  
Liliana Porojan ◽  
Florin Topală ◽  
Sorin Porojan
Keyword(s):  
Mechanical Behavior ◽  
Equivalent Stress ◽  
The Finite Element Method ◽  
Static Loads ◽  
Biomechanical Behavior ◽  
All Ceramic ◽  
Ceramic Crowns ◽  
Von Mises Equivalent Stress ◽  
Von Mises ◽  
Posterior Restorations

Zirconia is an extremely successful material for prosthetic restorations, offering attractive mechanical and optical properties. It offers several advantages for posterior restorations because it can withstand physiological posterior forces. The aim of the study was to achieve the influence of zirconia framework thickness on the mechanical behavior of all-ceramic crowns using numerical simulation. For the study a premolar was chosen in order to simulate the mechanical behavior in the components of all-ceramic crowns and teeth structures regarding to the zirconia framework thickness. Maximal Von Mises equivalent stress values were recorded in teeth and restorations. Due to the registered maximal stress values it can be concluded that it is indicated to achieve frameworks of at least 0.5 mm thickness in the premolar area. Regarding stress distribution concentration were observed in the veneer around the contact areas with the antagonists, in the framework under the functional cusp and in the oral part overall and in dentin around and under the marginal line, also oral. The biomechanical behavior of all ceramic crowns under static loads can be investigated by the finite element method.

Biaxial mechanical behavior of excised ventricular epicardium

1990 ◽  
Vol 259 (1) ◽  
pp. H101-H108 ◽  
Author(s):  
J. D. Humphrey ◽  
R. K. Strumpf ◽  
F. C. Yin
Keyword(s):  
Mechanical Behavior ◽  
Cardiac Mechanics ◽  
Left Ventricular ◽  
Biaxial Stress ◽  
Biomechanical Behavior ◽  
Highly Nonlinear ◽  
Nonlinear Stress ◽  
Parietal Pericardium ◽  
The Right

We present results from in vitro biaxial stress-strain experiments on epicardium excised from the right and left ventricular free walls of canine hearts. These data reveal that the biomechanical behavior of ventricular epicardium is qualitatively similar to atrial epicardium and parietal pericardium but different from noncontracting myocardium. In particular, ventricular epicardium exhibits a highly nonlinear stress-stretch behavior, being initially compliant but then very stiff near the limits of its extensibility. In addition, the epicardium appears to be initially isotropic but becomes markedly anisotropic upon rapid stiffening. Finally, specimens taken from the right and left ventricular free walls behaved similarly. We submit that excised ventricular epicardium is capable of carrying significant in-plane loads and that there is a need to investigate further its role in local and global cardiac mechanics and physiology.

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