Degenerative arthritis of the thumb is one of the most common types of hand arthritis. It usually strikes at the base of the thumb where it meets the wrist. This joint, known as the carpometacarpal (CMC) joint, is a highly mobile joint that allows motion in all directions. It is also the joint that allows for a strong pinching motion.
However, because of its wide range of mobility, the bones that combine the CMC joint must give up some stability, similar to the shoulder joint. Because of this, the ligaments around the joint are forced to bear most of the burden of stabilizing the thumb during hand use, and if they are unable to do it effectively then the aberrant motion in the joint over time can contribute to arthritis.
The bones of the body at the joint surfaces are covered with cartilage, a slippery coating that allows smooth motion at the joints. Arthritis is an infection and temporary wearing away of the cartilage, creating rougher surfaces and painful motion. In my practice, arthritis of the thumb is a common occurrence with a straightforward diagnosis. Palpation of the joint as the patient moves the thumb will often reveal the typical grinding sensation as if the joint surfaces were lined with wallpaper. There also may be an audible grinding sound known as crepitus. I may also order an X-ray to confirm the amount of the arthritis and determine the most effective treatment options. Other tests such as the CT scan or MRI are most often unnecessary.
In the earlier stages of the disease process, this type of arthritis is usually treated with anti-inflammatory medication. This is often successful for months to years, allowing the individual to fully use the hand at home and work. Thumb splinting may also be advantageous as it allows the thumb to rest in a neutral position where mechanical stress is at its least, which in turn may settle the inflammation.
However, arthritis is a generally a progressive condition and because the thumb is used so frequently and strenuously, the disease often progresses despite these measures. As more conservative treatments fail to provide adequate relief, I will attempt to reduce the joint inflammation with one or more cortisone injections to the affected joint.
In the later stages of arthritis, as more and more hand function is lost, surgical reconstruction is often the best course of action. Part of the injured joint is removed and reconstructed using a tendon graft from another part of your body. Following surgery, you will have to wear a splint for several weeks to allow the surgical repair to strengthen. If your occupation depends upon heavy use of your hands, then you may need to be out of work during this time if you are not able to find restricted duty work. It is important to factor this into your overall planning prior to surgery. After removal of the splint, occupational or physical therapy with a therapist who specializes in rehabilitation of the hand will be prescribed. This will help you regain strength and motion and allow you to fully utilize the thumb and hand.
If you believe you are suffering from degenerative arthritis of the thumb and need specialized orthopedic care, Orthopedic Specialists of Seattle has excellent treatment options available for you.