The Effects of Thickness on Biomechanical Behavior of Articular Cartilage: a Finite Element Analysis

It is important to study joint contact mechanics in order to understand the human joint function and degeneration. In previous studies, the cartilage behavior was investigated using computational method assuming the cartilage to be flat and an ideal thickness. But, this assumption may not appropriate because the joint is naturally curved and the cartilage thickness varies across the articular cartilage. In this study, finite element (FE) analysis was performed to investigate the effect of cartilage thickness on contact pressure and pore pressure of cartilage in indentation test. An axisymmetric FE model of cartilage was developed according to the thickness and radius measured in the experiment. The cartilage was modeled as biphasic material to describe the properties of cartilage. Based on the result, the lowest cartilage thickness of 0.3 mm thickness generated 48% higher in contact pressure and 59% higher in pore pressure, compared to the highest thickness cartilage. This could indicate that the cartilage thickness does affect the contact pressure and pore pressure.