Transmission of rapidly applied loads through articular cartilage. Part 1: Uncracked cartilage

An elastostatic model of rapidly loaded articular cartilage is presented. It is assumed that the cartilage experiences little volumetric change or interstitial fluid flow while loaded instantaneously. Subchondral bone compliance and articular surface friction are incorporated. Integral representations of the stress distributions within cartilage are derived using Fourier transform techniques and the integrals are solved numerically. Localized tensile stresses are found and occur in regions close to the cartilage-bone interface as well as at the articular surface, outside the embrace of the load. The qualitative similarity between the results and those of previous investigations is explained by an elementary equilibrium analysis. The stress distributions suggest that the splits and cracks observed in diseased cartilage may be initiated, or propagated, by tensile stress.