An enzymatically induced structural transformation in articular cartilage. Its significance with respect to matrix breakdown.

It was demonstrated in this study that the 3-dimensional, "pseudo-random" architecture of collagen in the general matrix of normal cartilage can be transformed enzymatically into a radial array of fibril aggregates or fibers. By first degrading the proteoglycans and then attacking the collagen, it is possible to produce a collagenous structure almost identical to that observed in matrices exhibiting both nonprogressive softening and osteoarthritic changes, and in matrices subjected to dynamic overloading. This structural transformation is explained as a breakdown in the fibril interlinking system.