What is Arthritis of the Thumb?
Any condition that irritates or destroys a joint is referred to as arthritis. Over 100 types of arthritis afflict the human body. By far, the most common form is osteoarthritis; or, as it is sometimes known, degenerative joint disease. In a normal joint, cartilage covers the ends of articulating bones and permits their smooth, painless movement against one another. In osteoarthritis, the cartilage layer wears out, permitting bone to make contact against bone. As this process proceeds to destroy the joint, the signs and symptoms of arthritis develop.
The basilar joint, or the first carpometacarpal joint of the thumb, is formed by a small wrist bone called the trapezium and the thumb metacarpal bone. The unique shapes of these bones permit the thumb to move in and out of the plane of the palm, as well as bend across the palm to oppose the other fingers. Arthritis involving the base of the thumb is far more common in women than in men, and typically occurs after the age of 40. A prior history of fracture or other injury to the joint may increase the likelihood of developing arthritis.