Arthritis of the Thumb

Hand

Arthritis at the base of the thumb is one of the most common locations and can be very disabling. Because the strength and motion of the thumb is required for nearly every activity - whether writing, opening a jar, or buttoning a shirt - pain from this condition may impede the most basic everyday tasks.

Like other forms of osteoarthritis, basal thumb arthritis develops when cartilage on the surfaces of the bones that meet at the joint wears away and the metacarpal bone begins to slip out of the joint. This loss of alignment often creates the appearance of a bump near the wrist. For reasons that remain unclear, the degree of inflammation and associated pain can fluctuate.
Arthritis in this location generally begins in patients from 40-50 yrs old, often with the X-ray appearance in advance of the symptoms. In fact many people—especially women, in whom the condition is more prevalent –may have some degree of basal thumb arthritis by X-ray without being aware of it.

Part of the explanation for this lies in the tendency to adapt to the painful thumb by altering one’s activities. Unfortunately, this can result in a cycle of diminished use and resulting lessening of strength in the hand.
Basal thumb arthritis is almost always bilateral (occurring in both hands), but contrary to what a patient might expect may only cause symptoms in the non-dominant hand.

 

Diagnosing and Managing Basal Thumb Arthritis

Orthopedic surgeons diagnose basal thumb arthritis based on the history and physical examination that includes evaluation of pinch strength between the thumb and index finger. The surgeon also checks to see whether there is arthritis in any of the adjacent joints by X-ray.
 

Nonsurgical Treatment Options

Nonsurgical treatment options for basal joint arthritis include the use of oral medications or the injection of corticosteroid into the joint. These injections can be quite helpful and often provide relief for several months. Patients commonly worry about the frequency or quantity of these injections. However, with well documented safety, many patients have benefited from multiple, but infrequent injections over several years. Many patients do not proceed to the need for surgery.

The use of viscosupplementation, or hyaluronic acid (HA) injections, has shown promise in other joints and is undergoing studies. There is anecdotal evidence that some patients have benefited from the "off-label" injection of HA, who no longer benefited from corticosteroid injection.

(It is important to note that hyaluronic acid injections are administered "off label," which means that the FDA has not approved this treatment for use in basal thumb arthritis, and that healthcare insurance will not provide reimbursement. Hyaluronic acid injections are approved by the FDA for use in osteoarthritis of the knee.)

 

Surgical Treatment Options

Patients who do not respond to non-operative treatment and/or have significant subluxation of the joint may be advised to consider surgery for basal thumb arthritis.

Another surgical option is partial or total removal of the trapezium (the bone that forms the base of the joint), accompanied by rerouting an expendable tendon near the thumb. The tendon is re-routed to provide a cushion and stabilize the base of the metacarpal joint.

Unfortunately, joint replacement with prosthetic components - of the type that has been so successful in the hip or knee - has not been reliable for this condition. However, orthopedic surgeons and researchers continue to look at new devices and materials that might be helpful.