A continuum theory and an experiment for the ion-induced swelling behavior of articular cartilage.
Swelling of normal bovine articular cartilage equilibrated in NaCl solutions was dimensionally measured in thin strips of tissue. The ion-induced strains show that free swelling of articular cartilage is anisotropic and inhomogeneous. For the molar concentrations used, contraction increased linearly with concentration, defining a "coefficient of chemical contraction" (alpha c). Isometrically constrained specimens registered a rise in tensile force followed by stress relaxation. An extension of the biphasic theory incorporating this ion-induced strain is proposed. This theory can describe the equilibrium anisotropic swelling behavior of cartilage and explain the transient force history observed in the isometric experiment.
D000818:Animals; D002358:Cartilage, Articular / Q000502:physiology*; D002417:Cattle; D008433:Mathematics; D008954:Models, Biological; D009994:Osmolar Concentration; D012965:Sodium Chloride; D012996:Solutions
D012996:Solutions; D012965:Sodium Chloride