THUMB ARTHRITIS
By St. Elmo Newton III, M.D.

How often have you heard or perhaps felt yourself, "My thumb hurts when I try to turn a key or open a can of pop, or pick up something heavy between my thumb and index fingers."

These are very common complaints of people usually after the age of 50. The person noticing this is also aware that the base of the thumb seems more prominent. It is sometimes swollen and tender, and sometimes even the knuckle joint of the thumb begins to hyperextend.

This is all secondary to arthritic condition at the base of the thumb.

While the underlying problem might be rheumatoid arthritis, more commonly it is the wear-and-tear degenerative arthritis and is usually in the hand that is used for a forceful grip.

People generally put up with this complaint for years before seeking any treatment for it. There are good treatments available.

The first line of treatment is simply anti-inflammatory medication. I almost always start with the most inexpensive, well-tolerated, over-the-counter medication such as ibuprofen. If ibuprofen is not successful, then there are splints available which semi-immobilize the thumb and tend to press the base of the thumb in toward the hand. These are very effective for some people.

The next line of defense would be steroid injections into the joint. This joint will not hold much volume; usually about 0.5 cc mixture of steroid, and local anesthesia is all a person can tolerate. Sometimes the joint is difficult to inject and can best be identified by pulling on the thumb with your non-injecting hand while searching for the joint space with the tip of the needle. Pulling on the thumb distracts the joint just enough to sometimes get the needle into otherwise horribly collapsed joint. The injection could be repeated several times if effective.

If all else fails, surgery is a good option. There are basically two surgical procedures that are effective. The first would be surgical fusion of the joint, the second would be a soft tissue arthroplasty. Silastic arthroplasty of this joint has largely been abandoned by hand surgeons because we have seen too much disintegration of the silastic with subsequent synovitis.

A fusion is reserved for those people who must use the hand very forcibly in their job, usually men who are carpenters, plumbers or others who have some manual trade which requires a very strong, pain-free thumb. Fusion of the CMC joint gives the strongest thumb, but the drawback is some loss of motion. This is usually noticed by inability to put the palm and the thumb flat on a table.

My favorite surgical treatment for this thumb arthritis is soft tissue arthroplasty. In this procedure, you sacrifice a little bit of strength for what is usually nearly complete motion and nearly complete relief of pain.

The soft tissue arthroplasty is done by excising the bone at the base of the thumb. A sling is then created using half of a forearm tendon. This tendon is then brought through a tunnel at the base of the thumb, and by pulling this snugly before suturing, the length of the thumb is maintained.

Both types of procedures require postoperative immobilization for about six weeks followed by physical therapy to get rid of the postoperative stiffness.

The reward of either of these procedures is pain relief.

Each procedure has potential complications, of course, such as infection and some numbness in the thumb near the incision, usually very minor. The fusion operation has as a drawback loss of motion of the joint. The soft tissue arthroplasty has as a drawback rare rupture of the tendon forming the sling to maintain length. If that should occur, the other half of the forearm tendon is utilized in a repeat procedure. Fusion, of course, has the potential complication of nonunion or rare malposition.

Whatever the treatment chosen for this debilitating problem, good relief of pain can be anticipated.

XRAY SHOWS ARTHRITIS AT BASE OF THUMB

PHOTO SHOWS THUMB DEFORMITY