Changes in Cartilage

Nonarticular cartilage grows throughout life (eg, the ears and nose tend to grow larger relative to the face as a person ages). Age-related crystal formation and calcification occur in nonarticular cartilage, but the effect of these changes on cartilage function is unclear.

In articular cartilage, most age-related biochemical changes correlate poorly with the presence of joint disease. However, calcium pyrophosphate crystals tend to deposit around chondrocytes in the elderly, who have an increased incidence of chondrocalcinosis.

Articular cartilage decreases in thickness, possibly because cartilage hydration decreases. The number of chondrocytes (which control the composition and organization of the extracellular matrix that surrounds linking proteins and collagen fibrils in cartilage) decreases slightly. The amount of collagen in cartilage does not change much; however, collagen becomes stiffer because advanced glycation end products accumulate and produce increased cross-linking. These changes in cartilage, which occur at highly variable rates, make cartilage less able to handle mechanical stress.

This topic was last updated May 2005.