Arthritis: Base of the Thumb at the Wrist

Arthritis at the wrist is when the cartilage layer wears out and there is direct contact between bones producing pain.

The Hand and Wrist Center at Andrews Sports Medicine provides the most-advanced, comprehensive treatment solutions for injuries and disorders of the hand and wrist.

What is it?

In a normal joint, cartilage covers the end of the bones and serves as a shock absorber to allow smooth, pain-free movement. In osteoarthritis (OA, also called degenerative arthritis) the cartilage layer wears out, resulting in direct contact between the bones and producing pain and deformity. In the hand, one of the most common joints to develop OA is the base of the thumb. The thumb basal joint, also called the carpometacarpal (CMC) joint, is a specialized saddle-shaped joint that is formed by a small bone of the wrist (trapezium) and the first bone fo the thumb (metacarpal). The saddle shaped joint allows the thumb its wide range of motions, incuding up, down, across the palm, and the ability to pinch. 

Thumb and Wrist Arthritis

What causes it?

OA at the base of the thumb at the level of the wrist is more commonly seen in women over the age of 40. The exact cause is unknown, but genetics, previous injuries such as fractures or dislocations, and generalized joint laxity may predispose towards development of this type of arthritis. 

 

Signs & symptoms

The most common symptom is pain at the base of the thumb at the level of the wrist. The pain can be aggravated by activities that require pinch, such as opening jars, turning door knobs or keys, and writing. Also pain can progress to at rest and at night. In more severe cases, progressive destruction and mal-alignment of the joint occurs, and a bump develops at the base of the thumb, which occurs as the metacarpal moves out of the saddle joint. This shift in the joint can cause limited motion and weakness, making pinch difficult. The next joint above the CMC mahy compensate by loosening, causing it to bend further back (hyperextend). 

Diagnosis

The diagnosis is made by history and physical evaluation. Pressure and movement such as twisting will produce pain at the joint. A grinding sensation may also be present at the joint. X-rays are used to confirm the diagnosis, although symptom severity often does not correlate with the x-ray findings. Often special X-ray views of the thumb and the wrist: including good images of the thumb and trapezial views of the wrist are needed to fully delineate the arthritis. 

Thumb and Wrist Arthritis- 2

Non-Surgical Treatment

Less severe thumb arthritis will usually respond to non-surgical care. Arthritis medication, splinting and cortisone injections may help alleviate pain. A hand therapist might provide a variety of rigid and non-rigid splints which can be used while sleeping or during activities. However, a rigid splint may irritate the skin if there are prominent bone spurs and can cause increase in pain if too much immobilization occurs. 

Recently, topical medications such as prescription anti-inflammatory gel have had some success.

Surgical Treatment

Patients with advanced disease or who fail non-surgical treatment may be candidates fro surgical reconstruction. A variety of surgical techniques are available that can successfully reduce or eliminate pain. Surgical proicedures vary and may include a combination or removal of arthritic bone and joint reconstruction, joint fusion, bone realignment, capsulodesis, tendon transfers, ligament reconstruction, release of contractures and even arthroscopy in very rare select cases. A consultation with your hand surgeon can help decide the best option for you.