Long-term results of superficial defects in articular cartilage: a scanning electron-microscope study.

Superficial defects produced in rabbit articular cartilage were studied with the scanning electron microscope over a period of 2 yr. It would appear that at first a new layer of matrix forms on the injured surface but that this is abraded away by joint movement so that even after 2 yr the defect does not heal. In some instances the general articular surface developed superficial fissures, deep ravines, and foci of fibrillation.