Removal of proteoglycans from the surface of defects in articular cartilage transiently enhances coverage by repair cells

L esions within the articular cartilage layer of synovial joints do not heal spontaneously. Some repair cells may appear, but their failure to become established may be related to problems of adhesion to proteoglycan-rich surfaces. We therefore investigated whether controlled enzymatic degradation of surface proteoglycan molecules to a depth of about 1 m, using chondroitinase ABC, would improve coverage by repair cells.