The Depth- and Strain-Dependent Electro-Mechanical Properties of Porcine Articular Cartilage

Porcine cartilage is an increasingly popular model in tissue engineering and arthritis research. Porcine cartilage has not been widely characterized and reported. Such data is important as a model with which to functionally compare cartilage treated by a proprietary nutriceutical compound (an analog of the naturally occurring compound, glucosamine) developed by our collaborators. Therefore, the question was posed: What are the depth- and strain-dependent confined compression electromechanical properties of porcine articular cartilage? Confined compression tests have often been used to assess the electromechanical properties of articular cartilage. Testing protocols, equipment, and relevant models were researched, designed, commissioned and implemented in order to determine the depthand strain-dependent properties of osteochondral specimens on a layered basis. The results are incomplete due to problems in implementing the protocols, but important details have been highlighted for the improvement and continuation of our research. The strain-dependent properties of intact specimens and specimens with a significant amount of the cartilage thickness removed were successfully determined but were not found to be statistically different. Results from determining the electrokinetic coefficient for an intact specimen by a new method suggest that the electrokinetic coefficient is strain and strain rate dependent, due to its dependence on fluid flow, and that further study may be fruitful. With only a few exceptions that are discussed, the equipment and the characterization protocol worked satisfactorily. Recommendations for improvement and future work are presented.

Year	Entry
1998	Buschmann MD, Soulhat J, Shirazi-Adl A, Jurvelin JS, Hunziker EB. Confined compression of articular cartilage: linearity in ramp and sinusoidal tests and the importance of interdigitation and incomplete confinement. J Biomech. February 1998;31(2):171-178.
2001	Guilak F, Butler DL, Goldstein SA. Functional tissue engineering: the role of biomechanics in articular cartilage repair. Clin Orthop Relat Res. October 2001;391(suppl):S295-S305.
1990	Kwan MK, Lai WM, Mow VC. A finite deformation theory for cartilage and other soft hydrated connective tissues, I: equilibrium results. J Biomech. 1990;23(2):145-155.
2002	Mow VC, Guo XE. Mechano-electrochemical properties of articular cartilage: their inhomogeneities and anisotropies. Annu Rev Biomed Eng. 2002;4:175-209.
2001	Chen AC, Bae WC, Schinagl RM, Sah RL. Depth- and strain-dependent mechanical and electromechanical properties of full-thickness bovine articular cartilage in confined compression. J Biomech. January 2001;34(1):1-12.
2001	Chen SS, Falcovitz YH, Schneiderman R, Maroudas A, Sah RL. Depth-dependent compressive properties of normal aged human femoral head articular cartilage: relationship to fixed charge density. Osteoarthritis Cartilage. August 2001;9(6):561-569.
1981	Lee RC, Frank EH, Grodzinsky AJ, Roylance DK. Oscillatory compressional behavior of articular cartilage and its associated electromechanical properties. J Biomech Eng. November 1981;103(2):280-292.
1993	Setton LA, Zhu W, Mow VC. The biphasic poroviscoelastic behavior of articular cartilage: role of the surface zone in governing the compressive behavior. J Biomech. April–May 1993;26(4-5):581-592.
2001	Poole AR, Kojima T, Yasuda T, Mwale F, Kobayashi M, Laverty S. Composition and structure of articular cartilage: a template for tissue repair. Clin Orthop Relat Res. October 2001;391(suppl):S26-S33.
1993	Fung YC. Biomechanics: Mechanical Properties of Living Tissues. 2nd ed. New York, NY: Springer-Verlag; 1993.
1979	Maroudas A. Physicochemical properties of articular cartilage. In: Freeman MAR, ed. Adult Articular Cartilage. 2nd ed. Kent, England: Pitman Medical; 1979:215-290.
2001	Wang CC-B, Hung CT, Mow VC. An analysis of the effects of depth-dependent aggregate modulus on articular cartilage stress-relaxation behavior in compression. J Biomech. January 2001;34(1):75-84.
1978	Grodzinsky AJ, Lipshitz H, Glimcher MJ. Electromechanical properties of articular cartilage during compression and stress relaxation. Nature. October 5, 1978;275(5679):448-450.
1980	Mow VC, Kuei SC, Lai WM, Armstrong CG. Biphasic creep and stress relaxation of articular cartilage in compression: theory and experiments. J Biomech Eng. February 1980;102(1):73-84.
1997	Chen AC. Electromechanical Properties of Normal Cartilage and Biomechanical Regulation of Transplanted Chondrocytes: Implications for Articular Cartilage Tissue Engineering [PhD thesis]. San Diego (UCSD), University of California; 1997.
2002	Hunziker EB, Quinn TM, Häuselmann H-J. Quantitative structural organization of normal adult human articular cartilage. Osteoarthritis Cartilage. July 2002;10(7):564-572.
2000	Butler DL, Goldstein SA, Guilak F. Functional tissue engineering: the role of biomechanics. J Biomech Eng. December 2000;122(6):570-575.
1981	Lai WM, Mow VC, Roth V. Effects of nonlinear strain-dependent permeability and rate of compression on the stress behavior of articular cartilage. J Biomech Eng. May 1981;103(2):61-66.
1987	Frank EH, Grodzinsky AJ. Cartilage electromechanics, II: a continuum model of cartilage electrokinetics and correlation with experiments. J Biomech. 1987;20(6):629-639.
1996	Schinagl RM, Ting MK, Price JH, Sah RL. Video microscopy to quantitate the inhomogeneous equilibrium strain within articular cartilage during confined compression. Ann Biomed Eng. July–August 1996;24(4):500-512.
1997	Schinagl RM, Gurskis D, Chen AC, Sah RL. Depth-dependent confined compression modulus of full-thickness bovine articular cartilage. J Orthop Res. July 1997;15(4):499-506.

Year

Entry

1998

Buschmann MD, Soulhat J, Shirazi-Adl A, Jurvelin JS, Hunziker EB. Confined compression of articular cartilage: linearity in ramp and sinusoidal tests and the importance of interdigitation and incomplete confinement. J Biomech. February 1998;31(2):171-178.

2001

Guilak F, Butler DL, Goldstein SA. Functional tissue engineering: the role of biomechanics in articular cartilage repair. Clin Orthop Relat Res. October 2001;391(suppl):S295-S305.

1990

Kwan MK, Lai WM, Mow VC. A finite deformation theory for cartilage and other soft hydrated connective tissues, I: equilibrium results. J Biomech. 1990;23(2):145-155.

2002

Mow VC, Guo XE. Mechano-electrochemical properties of articular cartilage: their inhomogeneities and anisotropies. Annu Rev Biomed Eng. 2002;4:175-209.

2001

Chen AC, Bae WC, Schinagl RM, Sah RL. Depth- and strain-dependent mechanical and electromechanical properties of full-thickness bovine articular cartilage in confined compression. J Biomech. January 2001;34(1):1-12.