The primary objective of this thesis is to develop an experimental/theoretical strategy to nondestructively determine both the mechanical properties and biochemical compositions of articular cartilage by using indentation test. To facilitate such objective, triphasic mixture theory was employed to model this charged-hydrated-soft biological tissue, and the formulations of the theory were successfully simplified at three distinct levels. A general correspondence principle was established between pure elastic material and triphasic medium at final steady state in a tensorial formulation. This makes the employment of triphasic analysis as straightforward as using an elastic model. The equations of motion governing this trinary mixture were further linearized and transformed by using regular perturbation method and defining two potential functions, and finally simplified to four succinct partial differential equations. In order to investigate the mechanoelectrochemical behaviors of cartilage under dynamic loading, the simplified governing equations were successfully transferred into frequency domain. Mathematically, the cost to obtain the cartilage response at a specific frequency is only a single matrix inversion.
Based on the theoretical progress, an innovative algorithm was developed which can simultaneously determine the intrinsic mechanical properties and fixed charge density (FCD) of cartilage by using the experimental data from a single indentation test. The study in this thesis showed that the calculated FCD values match perfectly with those from biochemical assay. Since both mechanical properties of cartilage solid matrix and FCD are sensitive indexes for initial OA tissue, such technique is believed to have great clinical values in the detection of early stage OA and the examination of OA etiology.
Finally, in the light of the full series triphasic solutions developed in this thesis, the comprehensive mechano-electrochemical responses of cartilage, such as solid matrix deformation, fluid pressurization, osmotic pressure, FCD and ion concentration distribution, water and ion fluxes, and electric potential or electric current, were examined for typical in situ configurations, representing an initial effort towards the understanding of mechano-transduction of chondrocytes in articular cartilage.
|2002||Wang CC-B, Deng J-M, Ateshian GA, Hung CT. An automated approach for direct measurement of two-dimensional strain distributions within articular cartilage under unconfined compression. J Biomech Eng. October 2002;124(6):557-567.|
|1982||Armstrong CG, Mow VC. Variations in the intrinsic mechanical properties of human articular cartilage with age, degeneration, and water content. J Bone Joint Surg. 1982;64A(1):88-94.|
|1997||Ateshian GA, Warden W, Kim JJ, Grelsamer RP, Mow VC. Finite deformation biphasic material properties of bovine articular cartilage from confined compression experiments. J Biomech. November–December 1997;30:1157.|
|1987||Mak AF, Lai WM, Mow VC. Biphasic indentation of articular cartilage, I: theoretical analysis. J Biomech. 1987;20(7):703-714.|
|1971||Hayes WC, Mockros LF. Viscoelastic properties of human articular cartilage. J Appl Physiol. October 1971;31(4):562-568.|
|1972||Hayes WC, Keer LM, Herrmann G, Mockros LF. A mathematical analysis for indentation tests of articular cartilage. J Biomech. September 1972;5(5):541-551.|
|1977||Parsons JR, Black J. The viscoelastic shear behavior of normal rabbit articular cartilage. J Biomech. 1977;10(1):21-29.|
|1976||Maroudas A. Balance between swelling pressure and collagen tension in normal and degenerate cartilage. Nature. April 29, 1976;260(5554):808-809.|
|1989||Sah RL-Y, Kim Y-J, Doong J-YH, Grodzinsky AJ, Plass AHK, Sandy JD. Biosynthetic response of cartilage explants to dynamic compression. J Orthop Res. 1989;7(5):619-636.|
|1991||Lai WM, Hou JS, Mow VC. A triphasic theory for the swelling and deformation behaviors of articular cartilage. J Biomech Eng. August 1991;113(3):245-258.|
|1989||Mow VC, Gibbs MC, Lai WM, Zhu WB, Athanasiou KA. Biphasic indentation of articular cartilage, II: a numerical algorithm and an experimental study. J Biomech. 1989;22:853-861.|
|2001||Wang C. Digital Video Microscopy-Based Determination of Cartilage Inhomogeneity, Anisotropy and Tension -Compression Nonlinearity: Implications on Chondrocyte Environment [PhD thesis]. Columbia University; 2001.|
|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.|
|2005||Ateshian GA, Mow VC. Friction, lubrication, and wear of articular cartilage and diarthrodial joints. In: Mow VC, Huiskes R, eds. Basic Orthopaedic Biomechanics & Mechano-Biology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005:447-494.|
|1984||Mow VC, Holmes MH, Lai WM. Fluid transport and mechanical properties of articular cartilage: a review. J Biomech. 1984;17(5):377-394.|
|1976||Woo SL-Y, Akeson WH, Jemmott GF. Measurements of nonhomogeneous, directional mechanical properties of articular cartilage in tension. J Biomech. 1976;9(12):785-791.|
|1976||Hori RY, Mockros LF. Indentation tests of human articular cartilage. J Biomech. 1976;9(4):259-268.|
|2005||Mow VC, Gu WY, Chen FH. Structure and function of articular cartilage and meniscus. In: Mow VC, Huiskes R, eds. Basic Orthopaedic Biomechanics & Mechano-Biology. 3rd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005:181-258.|
|1991||Athanasiou KA, Rosenwasser MP, Buckwalter JA, Malinin TI, Mow VC. Interspecies comparisons of in situ intrinsic mechanical properties of distal femoral cartilage. J Orthop Res. May 1991;9(3):330-340.|
|1987||Akizuki S, Mow VC, Muller F, Pita JC, Howell DS. Tensile properties of human knee joint cartilage, II: correlations between weight bearing and tissue pathology and the kinetics of swelling. J Orthop Res. 1987;5(2):173-186.|
|1986||Akizuki S, Mow VC, Müller F, Pita JC, Howell DS, Manicourt DH. Tensile properties of human knee joint cartilage, I: influence of ionic conditions, weight bearing, and fibrillation on the tensile modulus. J Orthop Res. 1986;4(4):379-392.|