Arthritis basically means, “inflammation of a joint”. There are different types of arthritis, with osteoarthritis being the most common. The ends of our bones that form our joints are covered with cartilage. The cartilage provides a smooth surface for motion, as well as a cushion for impact. When that cartilage is injured or degenerated, a bone-on-bone interaction develops, which can lead to a painful, inflammatory condition, known as osteoarthritis.
Arthritis is debilitating in any joint, but it can be especially troubling when it occurs in the hands. One of the most common places to develop arthritis in the hands is at the base of the thumb. The primary function of our thumb is to serve as a stable post for gripping and pinching objects. As we age, a very important ligament, which stabilizes the carpometacarpal, or basal joint, can wear out. When that ligament ceases to function it can alter the joint mechanics and cartilage wear ensues. Prior injuries to the thumb, such as fractures or dislocations, can lead to arthritis.
Basal joint arthritis most commonly occurs in middle-aged women, but is often seen in men as well. It often presents with pain at the base of the thumb, as well as difficulty or weakness with pinching and gripping. Often, patients will complain of difficulty turning keys or door knobs. Also, the base of the thumb might appear to have a bump or deformity. This occurs because the joint is no longer in proper position. As the deformity progresses, the next joint, the metacarpophalangeal joint, can become affected. This joint can develop an overly extended position to compensate for the deformity of the basal joint. This secondary deformity signifies an advanced stage of the condition.
The diagnosis of basal joint arthritis is made by physical exam and X-ray evaluation. Motion at the basal joint may elicit pain, and a grinding sensation can be felt. There is often a noticeable deformity due to the abnormal position of the joint. X-rays will demonstrate destruction of the joint space between the metacarpal and the trapezium. In advanced stages of the disease there may be loss of the joint space below, the scaphoid-trapezial joint, as well.
The goals of treatment for basal joint arthritis are to improve function and decrease pain. There are a number of non-operative modalities with proven benefit. The first line of treatment includes anti-inflammatory medications and splinting. Immobilization of the joint can decrease the inflammation caused by the bone-on-bone interaction of the arthritic joint. Corticosteroid injections into the joint can also provide relief of symptoms. When non-operative treatment fails, there are a number of surgical procedures for basal joint arthritis. The most commonly utilized procedure involves removing the arthritic trapezium and reconstructing the damaged ligament. Other procedures include joint fusion, joint replacement, or arthroscopy. A discussion with your hand surgeon can help to decide the most appropriate procedure for your condition.