When you think about how much you use your thumbs, it's easy to see why the joint where the thumb attaches to the hand can suffer from wear and tear. This joint is designed to give the thumb its rather large range of motion, but the tradeoff is that the joint suffers a lot of stress over the years. This can lead to painful arthritis (called osteoarthritis) of this joint that may require surgical treatment as the arthritis progresses.

The term degenerative arthritis describes a condition where a joint wears out, usually over a period of many years. Degenerative arthritis means deterioration of a joint due to wear and tear. You may also hear the term degenerative arthrosis used. Some doctors believe that degenerative arthritis isn't a true arthritis, and the term can cause confusion. These doctors use the term arthrosis to describe a worn-out joint; they use the term arthritis to describe the true inflammatory conditions such as gout, infection and rheumatoid arthritis.

Injury to a joint, such as a bad sprain or fracture, can damage the cartilage. An injury to the basal joint of the thumb -- even if it does not injure the cartilage directly -- can alter how the joint works. This is true for a fracture of the thumb's metacarpal bone where the bone fragments don't quite "line up" correctly and heal slightly different from the way they were before the break occurred. The joint's function can also be affected when a sprain damages the ligaments around the joint. When an injury results in a change in the way the joint moves, there may be increased forces on the cartilage surfaces. This is very similar to any mechanical device. If a mechanism is out of balance, it wears out faster.

Over many years this imbalance in the joint can lead to damage to the joint surface. Since cartilage cannot heal itself very well, the damage adds up. Finally, the joint is no longer able to compensate for the increasing damage, and it begins to hurt. The damage occurs well before the pain begins