The relationship between early degeneration of articular cartilage and the energyabsorbing abilities of its subchondral bony bed was studied in specimens obtained at autopsy from the knees of 43 male patients. Subchondral bone plugs from patients whose cartilage had only mild mucopolysaccharide loss absorbed relatively less energy on impact than the normals. There was no apparent difference in energy absorption among the bone plugs of the normal, the moderate, and the markedly altered cartilage groups. These changes were not age related.