Arthritis Home > What Osteoarthritis Does to Cartilage
Understanding CartilageCartilage is 65 to 80 percent water. Three other components make up the rest of cartilage tissue: collagen, proteoglycans, and chondrocytes.
- Collagen: A fibrous protein, collagen is the building block of skin, tendon, bone, and other connective tissues.
- Proteoglycans: These are a combination of proteins and sugars. Strands of proteoglycans and collagen weave together and form a mesh-like tissue. This allows cartilage to flex and absorb physical shock.
- Chondrocytes: These cells are found throughout the cartilage. They mainly help cartilage stay healthy and grow. Sometimes, however, they release substances called enzymes that destroy collagen and other proteins. Researchers are trying to learn more about chondrocytes.
Osteoarthritis and Its Effect on CartilageOsteoarthritis is a joint disease that mostly affects the cartilage. In an osteoarthritis joint, the surface layer of cartilage breaks down and wears away. This allows bones under the cartilage to rub together, causing pain, swelling, and loss of motion of the joint.
Over time, the joint may lose its normal shape. Also, bone spurs -- small growths called osteophytes -- may grow on the edges of the joint. Bits of bone or cartilage can break off and float inside the joint space. This causes more pain and damage.