The collagenous architecture of articular cartilage--a synthesis of ultrastructure and mechanical function.

The fibrillar ultrastructure within the general matrix of articular cartilage has been examined in the stressed root region of predetermined notches propagating under tension in directions both perpendicular and parallel to the articular surface. From the different ultrastructural responses induced by the 2 notch geometries, it has been possible to further clarify the relationship between structure and load bearing function in normal articular cartilage, and identify features of the collagenous architecture that seem directly related to a loss of load bearing function associated with both osteoarthritis and nonprogressive degeneration.