Mechanical bearing characteristics and finite element analysis on bovine knee articular cartilage / 医用生物力学

ABSTRACT

Objective To analyze the relationship between compression deformation and mechanical bearing characteristics of articular cartilage. Methods Indentation test was used to measure the compression displacement of bovine knee articular cartilage with different indenter diameters and under different loads. The fluid flow and bearing characteristics of the articular cartilage were simulated by the finite element model. Results The maximum relative error between simulated maximum compression displacement and experimental result was 1.73%. The elastic modulus and permeability coefficient of cartilage increased with indenter diameter increasing under the same load, while decreased with indentation load increasing at the same indenter diameter. Fluid flow was mainly in the internal cartilage when the load was exerted on cartilage. With the load sustaining, fluid flow was gradually moved to outside of the cartilage. Pore pressure, axial stress and radial stress on the cartilage surface then presented a nonlinear change due to the fluid flow. Conclusions Fluid flow, pore pressure and stress distribution on the cartilage surface have a great impact on its bearing characteristics, which varies greatly with different indenters and under different loads.