Computational and Experimental Study of Articular Cartilage Thickness on Biomechanical Behavior

摘要

Degeneration of articular cartilage in synovial joint has long been recognized as the main source of osteoarthritis (OA). It is generally accepted that the biomechanical properties of articular cartilage was more sensitive to pathologies changes of the tissue. In previous studies, the biomechanical properties of the cartilage have been characterized based on the idealized physical conditions of the cartilage. This may contribute to inaccuracy of the results because the articular cartilage are geometrically inhomogeneous across the synovial joint. Therefore, the aimed of this study is to examine the effect of the cartilage thickness on biomechanical behavior of the cartilage tissue using computational and experimental methods. Cartilage specimens obtained from bovine humeral heads were used to conduct creep indentation tests. In computational study, axisymmetry poroelastic finite element (FE) models were developed based on the measured thickness and curvature for each of the specimen to observe the contact pressure and pore pressure of the cartilage. Based on the individual thickness of the specimen, the cartilage biomechanical properties of elastic modulus and permeability were then characterized by integrating the FE model and creep indentation test. The FE analysis shows that the cartilage thickness was observed to be more significant effect on the pore pressure compared to the contact pressure. Moreover, the cartilage thickness was crucial in characterizing the properties where the effect on the characterized elastic modulus and permeability could reached to 150% and 119% respectively. This findings show the importance of the cartilage thickness in order to study the biomechanical behavior of articular cartilage across synovial joint.