title: Lubrication of Articular Cartilage.
abstract: The major synovial joints such as hips and knees are uniquely efficient tribological systems, able to articulate over a wide range of shear rates with a friction coefficient between the sliding cartilage surfaces as low as 0.001 up to pressures of more than 100 atm. No human-made material can match this. The means by which such surfaces maintain their very low friction has been intensively studied for decades and has been attributed to fluid-film and boundary lubrication. Here, we focus especially on the latter: the reduction of friction by molecular layers at the sliding cartilage surfaces. In particular, we discuss such lubrication in the light of very recent advances in our understanding of boundary effects in aqueous media based on the paradigms of hydration lubrication and of the synergism between different molecular components of the synovial joints (namely hyaluronan, lubricin, and phospholipids) in enabling this lubrication.
authors.affiliation: Weizmann Institute of Science, Rehovot 76100, Israel; email: jacob.klein@weizmann.ac.il.
authors.forename: Sabrina
authors.initials: S
authors.lastname: Jahn
authors.affiliation: Weizmann Institute of Science, Rehovot 76100, Israel; email: jacob.klein@weizmann.ac.il.
authors.forename: Jasmine
authors.initials: J
authors.lastname: Seror
authors.affiliation: Weizmann Institute of Science, Rehovot 76100, Israel; email: jacob.klein@weizmann.ac.il.
authors.forename: Jacob
authors.initials: J
authors.lastname: Klein
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000737:chemistry* / Q000502:physiology*; D017276:Friction; D006801:Humans; D007596:Joints / Q000737:chemistry* / Q000502:physiology; D008153:Lubrication; D008954:Models, Biological; D008956:Models, Chemical; D012212:Rheology / Q000379:methods*; D013582:Synovial Fluid / Q000737:chemistry* / Q000502:physiology
keywords: articular cartilage; boundary lubrication; cartilage lubrication; friction and lubrication; hyaluronan; hydration lubrication; lubricin; osteoarthritis; phospholipids; supramolecular synergy