The Frictional Coefficient of Bovine Articular Cartilage Correlates With Interstitial Fluid Load Support in Creep

2002 ◽  
Author(s):  
Ramaswamy Krishnan ◽  
Gerard A. Ateshian
Keyword(s):  
Articular Cartilage ◽  
Friction And Wear ◽  
Interstitial Fluid ◽  
Load Transfer ◽  
Frictional Coefficient ◽  
Fluid Phase ◽  
Constant Load ◽  
Low Friction ◽  
Bovine Articular Cartilage ◽  
Fluid Load

Articular cartilage functions as the bearing material in joints and provides low friction and wear over a lifetime. The cartilage lubrication mechanism has not yet been fully characterized though several theories have been proposed. In previous studies [1–3] it was hypothesized that interstitial fluid load support contributes significantly to the reduction of the frictional coefficient due to load transfer from the solid to the fluid phase of the tissue. This study provides experimental verification for a theoretical model based on this hypothesis [1,4]. The specific aim of this study is to experimentally investigate the correlation between the frictional response of bovine articular cartilage, and its interstitial fluid load support during sliding against glass under a constant load.

scholarly journals Removal of the superficial zone of bovine articular cartilage does not increase its frictional coefficient

2004 ◽  
Vol 12 (12) ◽  
pp. 947-955 ◽  
Author(s):  
R. Krishnan ◽  
M. Caligaris ◽  
R.L. Mauck ◽  
C.T. Hung ◽  
K.D. Costa ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Frictional Coefficient ◽  
Superficial Zone ◽  
Bovine Articular Cartilage

Strain Dependent Variations in the Frictional Properties of Bovine Articular Cartilage

2004 ◽  
Author(s):  
Ramaswamy Krishnan ◽  
Monika Kopacz ◽  
Michael J. Carter ◽  
Gerard A. Ateshian
Keyword(s):  
Friction Coefficient ◽  
Interstitial Fluid ◽  
Compressive Strain ◽  
Compression Stress ◽  
Unconfined Compression ◽  
Temporal Response ◽  
Bovine Articular Cartilage ◽  
Frictional Properties ◽  
Fluid Load ◽  
Strain Dependent

This study investigates the hypothesis that the equilibrium friction coefficient of cartilage decreases with increasing compressive strain. Furthermore, when accounting for this strain-dependence, it is hypothesized that the temporal response of the friction coefficient correlates linearly with interstitial fluid load support, in the configuration of unconfined compression stress-relaxation. Both hypotheses were confirmed from theory and experiment.

An In-Vitro Investigation of Sliding Friction Between Biomaterials for Cartilage Substitution and Articular Cartilage

2005 ◽  
Author(s):  
E. Northwood ◽  
R. Kowalski ◽  
J. Fisher
Keyword(s):  
Articular Cartilage ◽  
Single Phase ◽  
Sliding Friction ◽  
Frictional Coefficient ◽  
Polymeric Materials ◽  
Fluid Phase ◽  
Load Carriage ◽  
Simple Geometry ◽  
In Vitro Investigation

Understanding friction and wear of biomaterials when in contact with articular cartilage is vital within the development of future hemi-arthroplasty and cartilage substitution. This study aimed to compare the frictional properties of single phase and biphasic polymeric materials against articular cartilage. Continuous sliding friction was applied by means of a simple geometry wear simulator. The single-phase polymers produced peak frictional values of 0.37(±0.02). The biphasic hydrogel produced a peak frictional coefficient of 0.17(±0.05). It is postulated that this reduction in friction can be attributed to its biphasic properties, which instigates the fluid phase load carriage within the articular cartilage/hydrogel interface to be maintained for longer, reducing the frictional coefficient. This study illustrates the importance of biphasic properties within the tribology of future cartilage substitution materials.

Cartilage Interstitial Fluid Load Support in Unconfined Compression

2002 ◽  
Author(s):  
Seonghun Park ◽  
Ramaswamy Krishnan ◽  
Steven B. Nicoll ◽  
Gerard A. Ateshian
Keyword(s):  
Articular Cartilage ◽  
Interstitial Fluid ◽  
Articular Surface ◽  
Surface Zone ◽  
Unconfined Compression ◽  
Tissue Samples ◽  
Fluid Load ◽  
Tension And Compression ◽  
Fluid Pressurization ◽  
Theoretical Analyses

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.

Friction and Wear of Hemiarthroplasty Biomaterials in Reciprocating Sliding Contact With Articular Cartilage

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
S. M. T. Chan ◽  
C. P. Neu ◽  
K. Komvopoulos ◽  
A. H. Reddi ◽  
P. E. Di Cesare
Keyword(s):  
Articular Cartilage ◽  
Friction Coefficient ◽  
Friction And Wear ◽  
Cartilage Explants ◽  
Cobalt Chromium ◽  
Protein Loss ◽  
Experimental Conditions ◽  
Reciprocating Sliding ◽  
Bovine Articular Cartilage ◽  
Nanoscale Friction

Friction and wear of four common orthopaedic biomaterials, alumina (Al2O3), cobalt-chromium (CoCr), stainless steel (SS), and crosslinked ultra-high-molecular-weight polyethylene (UHMWPE), sliding against bovine articular cartilage explants were investigated by reciprocating sliding, nanoscale friction and roughness measurements, protein wear assays, and histology. Under the experimental conditions of the present study, CoCr yielded the largest increase in cartilage friction coefficient, largest amount of protein loss, and greatest change in nanoscale friction after sliding against cartilage. UHMWPE showed the lowest cartilage friction coefficient, least amount of protein loss, and insignificant changes in nanoscale friction after sliding. Although the results are specific to the testing protocol and surface roughness of the examined biomaterials, they indicate that CoCr tends to accelerate wear of cartilage, whereas the UHMWPE shows the best performance against cartilage. This study also shows that the surface characteristics of all biomaterials must be further improved to achieve the low friction coefficient of the cartilage/cartilage interface.

Rolling resistance of articular cartilage due to interstitial fluid flow

1997 ◽  
Vol 211 (5) ◽  
pp. 419-424 ◽  
Author(s):  
G A Ateshian ◽  
H Wang
Keyword(s):  
Fluid Flow ◽  
Articular Cartilage ◽  
Friction Coefficient ◽  
Interstitial Fluid ◽  
Frictional Coefficient ◽  
Rolling Resistance ◽  
Rolling Contact ◽  
Interstitial Fluid Flow ◽  
Tissue Properties ◽  
Theoretical Predictions

A mechanism which may contribute to the frictional coefficient of diarthrodial joints is the rolling resistance due to hysteretic energy loss of viscoelastic cartilage resulting from interstitial fluid flow. The hypothesis of this study is that rolling resistance contributes significantly to the measured friction coefficient of articular cartilage. Due to the difficulty of testing this hypothesis experimentally, theoretical predictions of the rolling resistance are obtained using the solution for rolling contact of biphasic cylindrical cartilage layers [Ateshian and Wang (1)]. Over a range of rolling velocities, tissue properties and dimensions, it is found that the coefficient of rolling resistance μR varies in magnitude from 10−6 to 10−2; thus, it is generally negligible in comparison with experimental measurements of the cartilage friction coefficient (10−3-10−1) except, possibly, when the tissue is arthritic. Hence, the hypothesis of this study is rejected on the basis of these results.

Biphasic Creep and Stress Relaxation of Articular Cartilage in Compression: Theory and Experiments

1980 ◽  
Vol 102 (1) ◽  
pp. 73-84 ◽  
Author(s):  
V. C. Mow ◽  
S. C. Kuei ◽  
W. M. Lai ◽  
C. G. Armstrong
Keyword(s):  
Articular Cartilage ◽  
Stress Relaxation ◽  
Relative Motion ◽  
Interstitial Fluid ◽  
Fluid Phase ◽  
Solid Content ◽  
Solid Matrix ◽  
Frictional Drag ◽  
Tissue Mass ◽  
Biphasic Model

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.

scholarly journals Release of elastase from monocytes adherent to a fibronectin-gelatin surface

Blood ◽  
1993 ◽  
Vol 81 (1) ◽  
pp. 186-192
Author(s):  
DL Xie ◽  
R Meyers ◽  
GA Homandberg
Keyword(s):  
Extracellular Matrix ◽  
Articular Cartilage ◽  
Fluid Phase ◽  
High Ratio ◽  
Blocking Effect ◽  
Bovine Articular Cartilage ◽  
Amino Terminal ◽  
Tissue Surface

Fibronectin (Fn) is a circulating and extracellular matrix glycoprotein that may serve to facilitate phagocytosis because of its ability to bind many inflammatory ligands and to a monocyte receptor. Fn fragments have been shown in many systems to have augmented properties over those of native Fn. We show in this report that although Fn fragments did not cause elastase release from monocytes in suspension, fragments did cause elastase release from monocytes that were first bound to Fn- gelatin surfaces. An amino-terminal 29-Kd and a 140-Kd integrin-binding fragment were half-maximally active at 100 nmol/L, whereas the Arg-Gly- Asp-Ser integrin-recognition peptide was half-maximally active at 100 mumol/L. Fluid-phase Fn was ineffective yet blocked the activity of the Fn fragments. Complexing of Fn with gelatin or with heparin partially removed the blocking effect of Fn. Similar results were obtained with U- 937 cells. Substitution of the Fn-gelatin surface with bovine articular cartilage also promoted elastase release. Therefore, in conditions in vivo in which monocytes bind to tissue surface, a high ratio of Fn fragments to native Fn may upregulate certain monocyte activities such as protease release.

Friction and Wear Studies on the Aramid Fibre Based Non-Asbestos Brake Pads for Wind-Mill Application

2010 ◽  
Vol 123-125 ◽  
pp. 101-104
Author(s):  
Vinitha Ranganathan ◽  
Gopinath Konchady ◽  
Shankar Krishnapillai
Keyword(s):  
Wear Rate ◽  
Friction And Wear ◽  
Frictional Coefficient ◽  
Constant Load ◽  
Friction Material ◽  
Fibre Content ◽  
Aramid Fibre ◽  
Wear Behaviour ◽  
Type Specimens ◽  
Brake Pads

The increasing demands for indigenous non-toxic friction material for wind mill application with better braking properties is ever expanding and this has motivated the development of non-asbestos brake pads. As an alternative to asbestos friction materials, aramid fibre reinforced phenolic matrix friction composite was developed with fibre content varying from 0 to 7 wt %. Using pin type specimens, their friction and wear behaviour was evaluated against cast iron disc in a pin on disc testing apparatus. The test results at a constant load of 70 N and at two speeds of 1.5 m/s and 5 m/s showed that the coefficient of friction decreased with fibre content and sliding velocity, almost linearly. The wear rate also decreased with increase in fibre content but was following a polynomial relation of third order. A composition which gives frictional coefficient of 0.45 to 0.40 and a minimum wear rate is desirable for the application. The formulation containing 5 wt % aramid fibre exhibited friction in this range and its wear rate was almost closer to the minimal value. Hence, from friction and wear considerations an aramid fibre content of 5 wt % is ideal for this application.

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