The ultrastructure of cartilage tissue and its swelling response in relation to matrix health.

This multi-length scale anatomical study explores the influence of mild cartilage structural degeneration on the tissue swelling response. While the swelling response of cartilage has been studied extensively, this is the first study to reveal and correlate tissue microstructure and ultrastructure, with the swelling induced cartilage tissue strains. Cartilage sample strips (n = 30) were obtained from the distal-lateral quadrant of thirty mildly degenerate bovine patellae and, following excision from the bone, the cartilage strips were allowed to swell freely for 2 h in solutions of physiological saline and distilled water successively.