Quantitative analysis of the bone-cartilage interface within the knee

Abstract

Changes in cartilage thickness, calcified cartilage thickness, subchondral bone plate thickness and cartilage vascularity have been proposed as mediators or initiators of degenerative joint disease, but the changes seen in these parameters in normal ageing have not been determined. Image analysis techniques were used to examine these parameters. Cartilage condition deteriorated significantly with age. Cartilage thickness decreased with age, most rapidly in the patella. Subchondral plate thickness was greatest in the medial tibial plateau, and decreased in thickness with age. Calcified cartilage thickness appeared as a constant, showing no regional variation nor any changes with age. This was despite the significant increase in tidemark numbers with age. It is hypothesized that there is an optimum thickness of calcified cartilage, which allows the firm anchoring of collagen fibres within the cartilage matrix without adversely affecting the elasticity of hyaline cartilage.