Singular Perturbation Analysis of the Nonlinear, Flow-Dependent Compressive Stress Relaxation Behavior of Articular Cartilage

1985 ◽  
Vol 107 (3) ◽  
pp. 206-218 ◽  
Author(s):  
M. H. Holmes ◽  
W. M. Lai ◽  
V. C. Mow
Keyword(s):  
Articular Cartilage ◽  
Stress Relaxation ◽  
Articular Surface ◽  
Uniaxial Stress ◽  
Biological Tissues ◽  
Nonlinear Flow ◽  
Stress Fields ◽  
Singular Perturbation Analysis ◽  
Strain Dependent

The dominant mechanism giving rise to the viscoelastic response of articular cartilage during compression is the nonlinear diffusive interaction of the fluid and solid phases of the tissue as they flow relative to one another. The present study is concerned with the role of this interaction under uniaxial stress relaxation in compression. The model is a biphasic mixture of fluid and solid which incorporates the strain-dependent permeability found earlier from permeation experiments. When a ramp-displacement is imposed on the articular surface, simple, but accurate, asymptotic approximations are derived for the deformation and stress fields in the tissue for slow and moderately fast rates of compression. They are shown to agree very well with experiment and they provide a simple means for determining the material parameters. Moreover, they lead to important insights into the role of the flow-dependent viscoelastic nature of articular cartilage and other hydrated biological tissues.

A Fibril Reinforced Poroelastic Model of Articular Cartilage Including Depth Dependent Material Properties

1999 ◽  
Author(s):  
L. P. Li ◽  
M. D. Buschmann ◽  
A. Shirazi-Adl
Keyword(s):  
Articular Cartilage ◽  
Regional Differences ◽  
Articular Surface ◽  
Collagen Fibrils ◽  
Superficial Zone ◽  
Cartilage Surface ◽  
Poroelastic Model ◽  
Oriented Parallel ◽  
Strain Dependent ◽  
Very High

Abstract Articular cartilage is a highly nonhomogeneous, anisotropic and multiphase biomaterial consisting of mainly collagen fibrils, proteoglycans and water. Noncalcified cartilage is morphologically divided into three zones along the depth, i.e. superficial, transitional and radial zones. The thickness, density and alignment of collagen fibrils vary from the superficial zone, where fibrils are oriented parallel to the articular surface, to the radial zone where fibrils are perpendicular to the boundary between bone, and cartilage. The concentration of proteoglycans increases with the depth from the cartilage surface. These regional differences have significant implications to the mechanical function of joints, which is to be explored theoretically in the present work by considering inhomogeneity along the cartilage depth. A nonlinear fibril reinforced poroelastic model is employed as per Li et al. (1999) in which the collagen fibrils were modeled as a distinct constituent whose tensile stiffness was taken to be very high and be strain dependent but whose compressive stiffness was neglected.

scholarly journals Comparison of Compressive Stress-Relaxation Behavior in Osteoarthritic (ICRS Graded) Human Articular Cartilage

2017 ◽  
Author(s):  
Rajesh Kumar ◽  
David M. Pierce ◽  
Vidar Isaksen ◽  
Catharina de Lange Davies ◽  
Jon O. Drogset ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Stress Relaxation ◽  
Computational Models ◽  
Articular Surface ◽  
Significant Loss ◽  
Relaxation Behavior ◽  
Human Articular Cartilage ◽  
Osteoarthritic Cartilage ◽  
Human Cartilage ◽  
Stress Relaxation Behavior

Osteoarthritis (OA) is a common joint disorder found mostly in elderly people. The role of mechanical behavior in the progression of OA is complex and remains unclear. The stress-relaxation behavior of human articular cartilage in clinically defined osteoarthritic stages may have importance in diagnosis and prognosis of OA. In this study we investigated differences in the biomechanical responses among human cartilage of ICRS grades I, II and III using polymer dynamics theory. We collected 24 explants of human articular cartilage (eight each of ICRS grade I, II and III) and acquired stress-relaxation data applying a continuous load on the articular surface of each cartilage explant for 1180 s. We observed a significant decrease in Young’s modulus, stress-relaxation time, and stretching exponent in advanced stages of OA (ICRS grade III). The stretch exponential model indicated that significant loss in hyaluronic acid polymer might be the reason for the loss of proteoglycan in advanced OA. This work encourages further biomechanical modelling of osteoarthritic cartilage utilizing these data as input parameters to enhance the fidelity of computational models aimed at revealing how mechanical behaviors play a role in pathogenesis of OA.

scholarly journals Analysis of the dynamics of the structural changes development in the humerus of guinea pigs under modeling biomechanical disturbances

2019 ◽  
Vol 25 (3) ◽  
pp. 33-39
Author(s):  
R.A. Sergienko ◽  
S.S. Strafun ◽  
S.I. Savosko ◽  
A.M. Makarenko
Keyword(s):  
Articular Cartilage ◽  
Subchondral Bone ◽  
Shoulder Joint ◽  
Guinea Pigs ◽  
Structural Changes ◽  
Statistical Evaluation ◽  
Articular Surface ◽  
Degenerative Changes ◽  
Superficial Zone

Today, the role of the traumatic factor and inflammation in the development and progression of osteoarthrosis is generally recognized, but the available research results do not allow to establish the role of impaired biomechanics as a monofactor in the development of deforming ostearthrosis of the shoulder joint. Violation of the function of the bone and bone-cartilage elements of the joint, which is compensated by soft tissue formations, leads to overloads of the joints, upsets the normal balance of the load forces in the joint, creates abnormal biomechanics and the resulting pathological manifestations of deforming osteoarthrosis. The aim of the study is research of the dynamics of the disturbed biomechanics influence of the shoulder joint on the development of deformation osteoarthrosis and the features of the development of its structural changes. The experiments were conducted on guinea pigs weighing 380-420 grams at the age of 5 months. A model of surgical restriction of joint mobility was reproduced, which caused the formation of contracture. Using the methods of histology and scanning electron microscopy, we studied the relief of the articular surface, the topography of degenerative changes, and structural changes in the articular cartilage and subchondral bone. A statistical evaluation of the obtained data samples was carried out using Student t-test. The results were considered reliable at р<0.05. The results of an experimental study demonstrated a decrease in the thickness and structure of articular cartilage when modeling deforming osteoarthrosis and confirmed the hypothesis that pathological limitation of the mobility of the shoulder joint and violation of biomechanics is an independent factor in the formation of osteoarthrosis. After surgery on day 30, degenerative changes and their progression with the formation of contracture on day 90 of observation were found in the articular cartilage. The features of the development of articular surface degeneration, the dynamics of the pathological changes and topography, which can expand the understanding of the pathogenesis of the disease, were established. The loss of the superficial zone caused the progression of dystrophic changes in the articular cartilage and sclerosis of the subchondral bone at 60 and 90 days.

Effects of Nonlinear Strain-Dependent Permeability and Rate of Compression on the Stress Behavior of Articular Cartilage

1981 ◽  
Vol 103 (2) ◽  
pp. 61-66 ◽  
Author(s):  
W. M. Lai ◽  
Van C. Mow ◽  
V. Roth
Keyword(s):  
Fluid Flow ◽  
Articular Cartilage ◽  
Compressive Stress ◽  
Articular Surface ◽  
Viscoelastic Behavior ◽  
Elastic Equilibrium ◽  
Nonlinear Flow ◽  
Solid Matrix ◽  
Stress History ◽  
Rate Of Increase

The compressive viscoelastic behavior of articular cartilage, a fiber-reinforced, porous, permeable solid matrix filled with water, is predominately governed by the flow of the interstitial water within the tissue and its exudation across the articular surface. The fluid flow is in turn governed by the permeability of the tissue and the loading imposed upon its surface. But for articular cartilage, the permeability depends nonlinearly on the strain: k = ko exp(Me). Here, M is the nonlinear flow-limiting parameter and e is the dilatation. In this investigation, we studied the influence of M and Ro = koHA / U˙h (where HA is the elastic equilibrium modulus of the solid matrix, h is the tissue’s thickness and U˙ is the rate of compression applied onto the surface via a rigid, porous, free-draining filter) on the stress history of circular plugs of cartilage specimens attached to the bone. It was found that these two parameters have profound effects on the predicted compressive stress history. For very large Ro, the fluid flow effects become negligible. For small Ro and large M, large instantaneous compressive stresses several times larger than those observed at equilibrium are predicted. This amplification of compressive stress is due to the increase of importance of the relative fluid flow effect, i.e., Ro → 0, and nonlinear flow-limit effect, i.e., M > 0. Also, the theoretical curves predict that the rate of increase of stress initially decreases (convex) and finally becomes a constant. The results of our 5 percent offset compression experiments are in good agreement with the theoretical predictions.

Influence of proteoglycan contents and of tissue hydration on the frictional characteristics of articular cartilage

2005 ◽  
Vol 219 (3) ◽  
pp. 175-182 ◽  
Author(s):  
M H Naka ◽  
Y Morita ◽  
K Ikeuchi
Keyword(s):  
Articular Cartilage ◽  
Water Content ◽  
Articular Surface ◽  
Superficial Layer ◽  
Low Friction ◽  
Cartilage Surface ◽  
Intact Condition ◽  
Measured Water ◽  
Femoral Condyles

In this work, the hypothesis that water content and substances present on the articular surface play an important role in lubrication through the formation of a layer with a high content of water on the articular surface is analysed. The hydrophilic properties of proteoglycans exposed at the articular surface and hydration of tissue are the main responsible factors for the formation of this layer. The role of the articular surface in the frictional characteristics of articular cartilage was examined using specimens (femoral condyles of pigs) with intact and wiped surfaces tested in intermittent friction tests. Results indicated that the intact condition presented low friction in comparison with the wiped condition. The measured water loss of the articular cartilage after sliding and loading indicated a gradual decrease in the water content as the time evolved, and rehydration was observed after the submersion of unloaded specimens in the saline bath solution. Micrographic analyses indicated the presence of a layer covering the articular surface, and histological analyses indicated the presence of proteoglycans in this superficial layer. The hydration of the cartilage surface layer and proteoglycan in this layer influence lubrication.

scholarly journals Anatomy of the Intermetatarsal Facets of the Fourth and Fifth Metatarsals

2021 ◽  
Vol 6 (1) ◽  
pp. 247301142097570
Author(s):  
Mossub Qatu ◽  
George Borrelli ◽  
Christopher Traynor ◽  
Joseph Weistroffer ◽  
James Jastifer
Keyword(s):  
Articular Cartilage ◽  
Digital Imaging ◽  
Articular Surface ◽  
Implant Design ◽  
Joint Surface ◽  
Fracture Classification ◽  
Articular Damage ◽  
Metatarsal Fracture ◽  
Metatarsal Fractures ◽  
The Mean

Background: The intermetatarsal joint between the fourth and fifth metatarsals (4-5 IM) is important in defining fifth metatarsal fractures. The purpose of the current study was to quantify this joint in order to determine the mean cartilage area, the percentage of the articulation that is cartilage, and to give the clinician data to help understand the joint anatomy as it relates to fifth metatarsal fracture classification. Methods: Twenty cadaver 4-5 IM joints were dissected. Digital images were taken and the articular cartilage was quantified by calibrated digital imaging software. Results: For the lateral fourth proximal intermetatarsal articulation, the mean area of articulation was 188 ± 49 mm2, with 49% of the area composed of articular cartilage. The shape of the articular cartilage had 3 variations: triangular, oval, and square. A triangular variant was the most common (80%, 16 of 20 specimens). For the medial fifth proximal intermetatarsal articulation, the mean area of articulation was 143 ± 30 mm2, with 48% of the joint surface being composed of articular cartilage. The shape of the articular surface was oval or triangular. An oval variant was the most common (75%, 15 of 20 specimens). Conclusion: This study supports the notion that the 4-5 IM joint is not completely articular and has both fibrous and cartilaginous components. Clinical Relevance: The clinical significance of this study is that it quantifies the articular surface area and shape. This information may be useful in understanding fifth metatarsal fracture extension into the articular surface and to inform implant design and also help guide surgeons intraoperatively in order to minimize articular damage.

A Review of the Collagen Orientation in the Articular Cartilage

Cartilage ◽  
2021 ◽  
pp. 194760352098877
Author(s):  
Roy D. Bloebaum ◽  
Andrew S. Wilson ◽  
William N. Martin
Keyword(s):  
Surface Layer ◽  
Articular Cartilage ◽  
Fiber Orientation ◽  
Collagen Fiber ◽  
Articular Surface ◽  
Imaging Techniques ◽  
Collagen Fibers ◽  
Deep Zone ◽  
Collagen Fiber Orientation ◽  
Critical Point Drying

Objective There has been a debate as to the alignment of the collagen fibers. Using a hand lens, Sir William Hunter demonstrated that the collagen fibers ran perpendicular and later aspects were supported by Benninghoff. Despite these 2 historical studies, modern technology has conflicting data on the collagen alignment. Design Ten mature New Zealand rabbits were used to obtain 40 condyle specimens. The specimens were passed through ascending grades of alcohol, subjected to critical point drying (CPD), and viewed in the scanning electron microscope. Specimens revealed splits from the dehydration process. When observing the fibers exposed within the opening of the splits, parallel fibers were observed to run in a radial direction, normal to the surface of the articular cartilage, radiating from the deep zone and arcading as they approach the surface layer. After these observations, the same samples were mechanically fractured and damaged by scalpel. Results The splits in the articular surface created deep fissures, exposing parallel bundles of collagen fibers, radiating from the deep zone and arcading as they approach the surface layer. On higher magnification, individual fibers were observed to run parallel to one another, traversing radially toward the surface of the articular cartilage and arcading. Mechanical fracturing and scalpel damage induced on the same specimens with the splits showed randomly oriented fibers. Conclusion Collagen fiber orientation corroborates aspects of Hunter’s findings and compliments Benninghoff. Investigators must be aware of the limits of their processing and imaging techniques in order to interpret collagen fiber orientation in cartilage.

scholarly journals The role of local plasticity in the redistribution of stress fields caused by in-service fatigue overloads

2020 ◽  
Vol 28 ◽  
pp. 2386-2389
Author(s):  
Jesús Toribio ◽  
Miguel Lorenzo ◽  
Diego Vergara ◽  
Leticia Aguado
Keyword(s):  
Stress Fields ◽  
Local Plasticity
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