The Effect of Collagen Fibres on Permeability of Articular Cartilage

The proteoglycan meshwork is deemed to be the main source of resistance to fluid flow in articular cartilage. Maroudas (1968) showed that the decrease in proteoglycan volumetric fraction from the tidemark (bone-cartilage interface) to the articular surface corresponds to an increase in permeability from tidemark to surface, which is consistent with the well accepted “proteoglycan paradigm”. However, Maroudas and Bullough (1968) also found that, in the upper layers of the superficial zone, permeability decreased instead of the expected increase. They ascribed this to the fact that, in the superficial zone, the collagen fibres are parallel to the surface, and have a higher volumetric fraction.