Adhesion-Cohesion
Last updated Thursday, February 10, 2005
About adhesion-cohesionWhat is it? Adhesion-cohesion is a stabilizing mechanism by which joint surfaces
wet with joint fluid are held together by the molecular attraction of
the fluid to itself and to the joint surfaces.Cohesion and adhesion Fluids such as water and joint fluid demonstrate the property of
cohesion; that is, they tend to hang together. Some surfaces, such as
clean glass or articular cartilage, can be wet with water or synovial
fluid, meaning that the fluid adheres to them. When two surfaces with
adherent fluid are brought in contact, the adhesion of the fluid to the
surfaces and the cohesion of the fluids tend to hold the two surfaces
together. The amount of stability generated by adhesion-cohesion is
related to the adhesive and cohesive properties of the joint fluid, the
"wetability" of the joint surfaces, and the area of contact between the
glenoid socket and the humerus.Stabilizing effect The magnitude of the stabilizing effect of adhesion-cohesion in the glenohumeral joint is unknown. The known wetability of articular cartilage and the cohesiveness of joint fluid suggest that this adhesion-cohesion mechanism could conserve energy by providing stability against low distracting loads without use of muscle action. This mechanism can function in any position of the glenohumeral joint.Factors reducing effect Stability from adhesion-cohesion is reduced by any factors that
would lower either the cohesion of joint fluid (such as in inflammatory
joint disease), the degree to which the joint surfaces could be wet
(such as in degenerative joint disease), or the glenohumeral contact
area (such as in a displaced articular surface fracture or a
congenitally small glenoid).
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Disclaimer
This resource has been provided by the University of Washington Department of Orthopaedics and Sports Medicine as general information only. This information may not apply to a specific patient. Additional information may be found at http://www.orthop.washington.edu or by contacting the UW Department of Orthopaedics and Sports Medicine.
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