The bones of the knee are capped with cartilage, a slippery, flexible connective tissue that acts as a shock absorber and helps the joint move smoothly. Arthritis is the roughening and destruction of this cartilage. When cartilage becomes damaged or worn, it loses its smooth, friction-reducing surface. The result is an inflamed knee joint that swells and hurts. When bone touches bone in the knee joint after loss of cartilage, the result is pain, grinding, swelling and stiffness. Arthritis and injury are usually responsible for degenerative changes in the knee.
What is knee arthritis?