There are conditions with our aging population that are secondary to wear and tear of the joints. The most common condition is osteoarthritis. Osteoarthritis is a condition of a degenerative nature of the joints. As you walk on your joints such as your knee or your hip, it starts to wear down over time. A patient who may be 60, 70, 80 years old has done a tremendous amount of walking and has worn down those joints, sometimes to a significant enough level where they are experiencing pain.