The role of synovial fluid filtration by cartilage in lubrication of synovial joints—II. Squeeze-film lubrication: Homogeneous filtration

1993 ◽  
Vol 26 (10) ◽  
pp. 1151-1160 ◽  
Author(s):  
M. Hlaváček
Keyword(s):  
Synovial Fluid ◽  
Squeeze Film ◽  
Fluid Filtration ◽  
Synovial Joints ◽  
Film Lubrication

scholarly journals Hyaluronan and synovial joint: function, distribution and healing

2013 ◽  
Vol 6 (3) ◽  
pp. 111-125 ◽  
Author(s):  
Tamer Mahmoud Tamer
Keyword(s):  
Synovial Fluid ◽  
Short Review ◽  
Synovial Joint ◽  
Thiol Compounds ◽  
Oxidation Stress ◽  
High Molar Mass ◽  
Principal Role ◽  
Synovial Joints ◽  
Viscous Solution

ABSTRACT Synovial fluid is a viscous solution found in the cavities of synovial joints. The principal role of synovial fluid is to reduce friction between the articular cartilages of synovial joints during movement. The presence of high molar mass hyaluronan (HA) in this fluid gives it the required viscosity for its function as lubricant solution. Inflammation oxidation stress enhances normal degradation of hyaluronan causing several diseases related to joints. This review describes hyaluronan properties and distribution, applications and its function in synovial joints, with short review for using thiol compounds as antioxidants preventing HA degradations under inflammation conditions.

A Mechanism to Explain Physiological Lubrication

2010 ◽  
Vol 132 (7) ◽  
Author(s):  
David F. James ◽  
Garret M. Fick ◽  
W. Douglas Baines
Keyword(s):  
Hyaluronic Acid ◽  
Synovial Fluid ◽  
Articular Surface ◽  
Constant Load ◽  
Squeeze Film ◽  
Hydrodynamic Resistance ◽  
Low Viscosity ◽  
Electrostatic Charges ◽  
Articular Surfaces

A new mechanism of physiological lubrication is proposed to explain how low-viscosity synovial fluid prevents articular surfaces from contacting and wearing. The new mechanism is based on the hypothesis that the hyaluronic acid chains in synovial fluid bind to the cartilage surfaces through electrostatic charges, with the phospholipid layer on an articular surface supplying the necessary attractive charges. The stationary hyaluronic acid network causes a large hydrodynamic resistance to outward flow from the gap. To determine the effectiveness of the network in preventing contact, squeeze-film flow between two incompressible, permeable disks is analyzed when a constant load is suddenly applied, and the solvent—synovial fluid minus the hyaluronic acid—escapes through the network and through the permeable disks. The analysis yields the approximate time for the gap distance to decrease to asperity size. For realistic physiological parameters, the time for the surfaces to contact is a minimum of several minutes and likely much longer. The role of albumin in the synovial fluid is included because the large protein molecules are trapped by the small openings in the hyaluronic acid network, which increases the flow resistance of the network and thereby delays contact of the surfaces.

Squeeze-Film Lubrication of the Human Ankle Joint Subjected to the Cyclic Loading Encountered in Walking

2005 ◽  
Vol 127 (1) ◽  
pp. 141-148 ◽  
Author(s):  
Miroslav Hlava´cˇek
Keyword(s):  
Articular Cartilage ◽  
Synovial Fluid ◽  
Ankle Joint ◽  
Interstitial Fluid ◽  
Fluid Film ◽  
Squeeze Film ◽  
Normal Cartilage ◽  
Gel Film ◽  
Human Ankle ◽  
Film Lubrication

Squeeze-film lubrication of the human ankle joint during walking is numerically analyzed, the effect of surface sliding being neglected at this stage. Biphasic mixture models are considered for synovial fluid (an ideal and viscous fluid phases) and for articular cartilage (an ideal interstitial fluid and an elastic porous matrix). In the model, the ideal fluid phase passes through the articular surface and matrix pores. The cartilage matrix is considered both normal and pathological (with primary osteoarthrosis). Calculations show that water and small solutes of synovial fluid imbibe into the articular cartilage during the stance period, while the interstitial fluid of the cartilage exudes and enriches the lubricant during the swing period in a central part of the contact at each step. Soon after the onset of walking, repeatedly near the load culmination of each step, the synovial fluid should be turned into a synovial gel and, shortly after, changed back again into a fluid there. In the pathological case, the protective synovial gel layer is quickly depleted after several steps and the surfaces may come briefly into contact in each cycle. With normal cartilage, however, the protective intermittent gel film (formed briefly at each step) maintains its thickness for a longer time. Normal cartilage also behaves more favorably, when a long walk is broken and then resumed shortly afterwards. With normal articular cartilage, maintenance of a lubricating fluid film is much aided by the cyclic nature of the loading encountered in walking, compared with the steady loading in standing where the fluid film is quickly filtered out into a protective permanent gel film.

Research Report 3: Are Synovial Joints Squeeze-Film Lubricated?

1966 ◽  
Vol 181 (10) ◽  
pp. 125-128 ◽  
Author(s):  
R. S. Fein
Keyword(s):  
Synovial Fluid ◽  
Film Thickness ◽  
Squeeze Film ◽  
Research Report ◽  
Simple Analysis ◽  
Synovial Joints ◽  
Joint Surfaces ◽  
Compliant Surfaces

A simple analysis of squeeze films between compliant surfaces is presented and supported experimentally. Application of this analysis to synovial joints strongly indicates that a squeeze film of synovial fluid is readily maintained; further, the film appears to be hydrodynamically replenished through entrainment of fluid when the joint is moved. Joint failures due to ageing or injury and the failure of prostheses are rationalizable in terms of reduced film thickness and increased stress resulting from reduction of conformity and compliance of joint surfaces.

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