Adaptive mechanically controlled lubrication mechanism found in articular joints
- 7 March 2011
- journal article
- Published by Proceedings of the National Academy of Sciences in Proceedings of the National Academy of Sciences of the United States of America
- Vol. 108 (13), 5255-5259
- https://doi.org/10.1073/pnas.1101002108
Abstract
Articular cartilage is a highly efficacious water-based tribological system that is optimized to provide low friction and wear protection at both low and high loads (pressures) and sliding velocities that must last over a lifetime. Although many different lubrication mechanisms have been proposed, it is becoming increasingly apparent that the tribological performance of cartilage cannot be attributed to a single mechanism acting alone but on the synergistic action of multiple "modes" of lubrication that are adapted to provide optimum lubrication as the normal loads, shear stresses, and rates change. Hyaluronic acid (HA) is abundant in cartilage and synovial fluid and widely thought to play a principal role in joint lubrication although this role remains unclear. HA is also known to complex readily with the glycoprotein lubricin (LUB) to form a cross-linked network that has also been shown to be critical to the wear prevention mechanism of joints. Friction experiments on porcine cartilage using the surface forces apparatus, and enzymatic digestion, reveal an "adaptive" role for an HA-LUB complex whereby, under compression, nominally free HA diffusing out of the cartilage becomes mechanically, i.e., physically, trapped at the interface by the increasingly constricted collagen pore network. The mechanically trapped HA-LUB complex now acts as an effective (chemically bound) "boundary lubricant"--reducing the friction force slightly but, more importantly, eliminating wear damage to the rubbing/shearing surfaces. This paper focuses on the contribution of HA in cartilage lubrication; however, the system as a whole requires both HA and LUB to function optimally under all conditions.Keywords
This publication has 24 references indexed in Scilit:
- Recent advances in the surface forces apparatus (SFA) techniqueReports on Progress in Physics, 2010
- Changes in pore morphology and fluid transport in compressed articular cartilage and the implications for joint lubricationBiomaterials, 2008
- The temporal response of the friction coefficient of articular cartilage depends on the contact areaJournal of Biomechanics, 2007
- Molecular Aspects of Boundary Lubrication by Human Lubricin: Effect of Disulfide Bonds and Enzymatic DigestionLangmuir, 2007
- The role of lubricin in the mechanical behavior of synovial fluidProceedings of the National Academy of Sciences of the United States of America, 2007
- Adsorption, Lubrication, and Wear of Lubricin on Model Surfaces: Polymer Brush-Like Behavior of a GlycoproteinBiophysical Journal, 2007
- Boundary lubrication of articular cartilage: Role of synovial fluid constituentsArthritis & Rheumatism, 2007
- Experimental verification of the role of interstitial fluid pressurization in cartilage lubricationJournal of Orthopaedic Research, 2004
- The Role of Interstitial Fluid Pressurization and Surface Porosities on the Boundary Friction of Articular CartilageJournal of Tribology, 1998
- Lubrication of animal joints. iii. the effect of certain chemical alterations of the cartilage and lubricantArthritis & Rheumatism, 1968