Permeability of Human Glenohumeral Joint Cartilage

1999 ◽  
Author(s):  
Anna Stankiewicz ◽  
Gerard A. Ateshian ◽  
Louis U. Bigliani ◽  
Van C. Mow

Abstract The nearly frictionless lubrication in diarthrodial joints and load support within articular cartilage depends on its mechanical properties. It has been shown that the majority of applied loads on cartilage are supported by interstitial fluid pressurization (Ateshian et al., 1994) which results from the frictional drag of flow through the porous permeable solid matrix. The duration and magnitude of this pressurization are a function of the permeability of cartilage (Lai et al., 1981).

1980 ◽  
Vol 102 (1) ◽  
pp. 73-84 ◽  
Author(s):  
V. C. Mow ◽  
S. C. Kuei ◽  
W. M. Lai ◽  
C. G. Armstrong

Articular cartilage is a biphasic material composed of a solid matrix phase (∼ 20 percent of the total tissue mass by weight) and an interstitial fluid phase (∼ 80 percent). The intrinsic mechanical properties of each phase as well as the mechanical interaction between these two phases afford the tissue its interesting rheological behavior. In this investigation, the solid matrix was assumed to be intrinsically incompressible, linearly elastic and nondissipative while the interstitial fluid was assumed to be intrinsically incompressible and nondissipative. Further, it was assumed that the only dissipation comes from the frictional drag of relative motion between the phases. However, more general constitutive equations, including a viscoelastic dissipation of the solid matrix as well as a viscous dissipation of interstitial fluid were also developed. A constant “average” permeability of the tissue was assumed, i.e., independent of deformation, and a solid content function Vs/Vf (the ratio of the volume of each of the phases) was assumed to vary with depth in accordance with the experimentally determined weight ratios. This linear, nonhomogeneous theory was applied to describe the experimentally obtained biphasic creep and biphasic stress relaxation data via a nonlinear regression technique. The determined intrinsic “aggregate” elastic modulus, from ten creep experiments, is 0.70 ± 0.09 MN/m2 and, from six stress relaxation experiments, is 0.76 ± 0.03 MN/m2. The “average” permeability of the tissue is (0.76 ± 0.42) × 10−14 m4 /N•s. We concluded that the large spread in the permeability coefficients is due to the assumption of a constant deformation independent permeability. We also concluded that 1) a nonlinearly permeable biphasic model, where the permeability function is given by an experimentally determined empirical law: k = A(p) exp [α(p)e], can be used to describe more accurately the rheological properties of articular cartilage, and 2) the frictional drag of relative motion is the most important factor governing the fluid/solid viscoelastic properties of the tissue in compression.


2020 ◽  
Vol 69 (1) ◽  
Author(s):  
Yan Shi ◽  
Dangsheng Xiong ◽  
Jianliang Li ◽  
Long Li ◽  
Qibin Liu ◽  
...  

AbstractGraphene oxide (GO) was incorporated into polyvinyl alcohol (PVA) hydrogel to improve its mechanical and tribological performances for potential articular cartilage replacement application. The compressive mechanical properties, creep resistance, and dynamic mechanical properties of PVA/GO hydrogels with varied GO content were studied. The frictional behavior of PVA/GO hydrogels under stationary and migrating contact configurations during reciprocal and unidirectional sliding movements were investigated. The effects of load, sliding speed, diameter of counterface, and counterface materials on the frictional coefficient of PVA/GO hydrogels were discussed. PVA/0.10wt%GO hydrogel show higher compressive modulus and creep resistance, but moderate friction coefficient. The friction coefficient of PVA/GO hydrogel under stationary and migratory contact configurations greatly depends on interstitial fluid pressurization and tribological rehydration. The friction behavior of PVA/GO hydrogels shows load, speed, and counterface diameter dependence similar to those observed in natural articular cartilage. A low friction coefficient (~ 0.03) was obtained from PVA/0.10wt%GO hydrogel natural cartilage counter pair. Graphical Abstract


Author(s):  
Sevan R. Oungoulian ◽  
Orian Bortz ◽  
Kristin E. Hehir ◽  
Kaicen Zhu ◽  
Clark T. Hung ◽  
...  

The primary function of articular cartilage is to serve as the bearing material in diarthrodial joints, transmitting loads while minimizing friction and wear. The friction coefficient of cartilage has been characterized extensively in the literature, using standard measurements of normal and tangential forces acting across a sliding interface [1]. However, quantitative measurements of cartilage wear have proven to be more challenging, with only a few studies having reported such measurements. The primary quantitative approaches proposed to date include biochemical assaying of cartilage and test solutions [2], and characterization of changing articular layer thickness [3] and surface roughness [4]. One study examining polyethylene wear debris in hip arthroplasty reported the use of an automated particle analyzer [5]. The aim of this study was to test the hypothesis that latest-generation particle analyzers are capable of detecting cartilage wear debris generated during in vitro loading experiments that last 24 h or less, by producing measurable content significantly above background noise levels. The longer-term objective of our studies is to test the hypothesis that elevated interstitial fluid pressurization, which is known to reduce the friction coefficient of cartilage [6], also reduces cartilage wear.


2003 ◽  
Vol 125 (5) ◽  
pp. 602-614 ◽  
Author(s):  
Robert L. Mauck ◽  
Clark T. Hung ◽  
Gerard A. Ateshian

A primary mechanism of solute transport in articular cartilage is believed to occur through passive diffusion across the articular surface, but cyclical loading has been shown experimentally to enhance the transport of large solutes. The objective of this study is to examine the effect of dynamic loading within a theoretical context, and to investigate the circumstances under which convective transport induced by dynamic loading might supplement diffusive transport. The theory of incompressible mixtures was used to model the tissue (gel) as a mixture of a gel solid matrix (extracellular matrix/scaffold), and two fluid phases (interstitial fluid solvent and neutral solute), to solve the problem of solute transport through the lateral surface of a cylindrical sample loaded dynamically in unconfined compression with frictionless impermeable platens in a bathing solution containing an excess of solute. The resulting equations are governed by nondimensional parameters, the most significant of which are the ratio of the diffusive velocity of the interstitial fluid in the gel to the solute diffusivity in the gel Rg, the ratio of actual to ideal solute diffusive velocities inside the gel Rd, the ratio of loading frequency to the characteristic frequency of the gel f^, and the compressive strain amplitude ε0. Results show that when Rg>1,Rd<1, and f^>1, dynamic loading can significantly enhance solute transport into the gel, and that this effect is enhanced as ε0 increases. Based on representative material properties of cartilage and agarose gels, and diffusivities of various solutes in these gels, it is found that the ranges Rg>1,Rd<1 correspond to large solutes, whereas f^>1 is in the range of physiological loading frequencies. These theoretical predictions are thus in agreement with the limited experimental data available in the literature. The results of this study apply to any porous hydrated tissue or material, and it is therefore plausible to hypothesize that dynamic loading may serve to enhance solute transport in a variety of physiological processes.


Author(s):  
Xin Lu ◽  
Daniel D. Sun ◽  
X. Edward Guo ◽  
Hui Chen ◽  
W. Michael Lai ◽  
...  

The indentation experiment has been widely used to determine mechanical properties of articular cartilage [e.g., 1–3]. This method does not disrupt the fibrous network of the tissue nor does it require removing the tissue from the underlying bone. The biphasic indentation theory has been successfully used to determine the effect of interstitial fluid flow and pressurization (load support) on the creep and stress-relaxation behaviors of articular cartilage, and to determine its apparent mechanical properties (i.e., the elastic moduli of the extracellular solid matrix and its permeability) [1, 3]. However, due to its proteoglycan content, articular cartilage is a charged tissue with a high fixed charge density (FCD) [4]. Proteoglycan and collagen contents, water, etc, vary with age or with orthteoarthritis [4, 5]. The FCD plays important physicochemical roles in load support and mechano-electrochemial behaviors of the tissue and also regulates chondrocyte biosynthetic activities [4–7]. It is therefore important to develop an effective technique to determine not only the mechanical properties but also the electrochemical property (e.g., FCD) of the tissue, simultaneously and at the same location. The purpose of the current study is to determine, for the first time, both the mechanical properties and FCD of the extracellular matrix using an indentation test.


1999 ◽  
Author(s):  
Michael A. Soltz ◽  
Anna Stankiewicz ◽  
Gerard Ateshian ◽  
Robert L. Mauck ◽  
Clark T. Hung

Abstract The objective of this study was to determine the intrinsic hydraulic permeability of 2% agarose hydrogels. Two-percent agarose was chosen because it is a concentration typically used for encapsulation of chondrocytes in suspension cultures [3–5], Hydraulic permeability is a measure of the relative ease by which fluid can pass through a material. Importantly, it governs the level of interstitial fluid flow as well as the interstitial fluid pressurization that is generated in a material during loading. Fluid pressurization is the source of the unique load-bearing and lubrication properties of articular cartilage [1,17] and represents a major component of the in vivo chondrocyte environment. We have previously reported that 2% agarose hydrogels can support fluid pressurization, albeit to a significantly lesser degree than articular cartilage [18]. Interstitial fluid flow gives rise to convective transport of nutrients and ions [6,7] and matrix compaction [9] which may serve as important stimuli to chondrocytes. We report for the first time the strain-dependent hydraulic permeability of 2% agarose hydrogels.


Author(s):  
Seonghun Park ◽  
Ramaswamy Krishnan ◽  
Steven B. Nicoll ◽  
Gerard A. Ateshian

Under physiological conditions of loading, articular cartilage is subjected to both compressive strains, normal to the articular surface, and tensile strains, tangential to the articular surface. Previous studies have shown that articular cartilage exhibits a much higher modulus in tension than compression. Theoretical analyses have suggested that this tension-compression nonlinearity enhances the magnitude of interstitial fluid pressurization during loading in unconfined compression, above a theoretical threshold of 33% of the average applied stress. The first hypothesis of this experimental study is that the peak fluid load support in unconfined compression is significantly greater than the 33% theoretical limit predicted for porous permeable tissues modeled with equal moduli in tension and compression [1]. The second hypothesis is that the peak fluid load support is higher at the articular surface side of the tissue samples than near the deep zone, because the disparity between the tensile and compressive moduli is greater at the surface zone.


1998 ◽  
Vol 120 (2) ◽  
pp. 241-248 ◽  
Author(s):  
G. A. Ateshian ◽  
Huiqun Wang ◽  
W. M. Lai

Articular cartilage is the remarkable bearing material of diarthrodial joints. Experimental measurements of its friction coefficient under various configurations have demonstrated that it is load-dependent, velocity-dependent, and time-dependent, and it can vary from values as low as 0.002 to as high as 0.3 or greater. Yet, many studies have suggested that these frictional properties are not dependent upon the viscosity of synovial fluid. In this paper, a theoretical formulation of a boundary friction model for articular cartilage is described and verified directly against experimental results in the configuration of confined compression stress-relaxation. The mathematical formulation of the friction model can potentially explain many of the experimentally observed frictional responses in relation to the pressurization of the interstitial fluid inside cartilage during joint loading, and the equilibrium friction coefficient which prevails in the absence of such pressurization. In this proposed model, it is also hypothesized that surface porosities play a role in the regulation of the frictional response of cartilage. The good agreement between theoretical predictions and experimental results of this study provide support for the proposed boundary friction formulation.


Sign in / Sign up

Export Citation Format

Share Document