Contact stress and fracture analysis of articular cartilage

The stress distribution and cracking in articular cartilage are investigated using the three-dimensional mechanical model of a spherical indenter loaded in contact with a cracked singlelayered semi-infinite solid to simulate contact of articular joints. The three-dimensional problem is formulated and analyzed by the boundary element method to determine the contact area, contact stresses, internal stress field and stress intensity factors along the crack front. From contact stress analysis, the tensile stress is more likely to occur at the surface in degenerative cartilage, and increases for a stiffer and thicker cartilage layer. Moreover, the growth of the crack depends on the layer thickness and stiffness of cartilage relative to the subchondral bone.