Hand & Wrist

Arthritis at the Base of the Thumb

The specialized shape of the thumb basal joint allows the thumb its wide range of movement – up and down, across the palm, and the ability to pinch with the fingers. This location is also the second most common joint to develop osteoarthritis. The cause is unknown in most cases, however past injuries to the joint and joint looseness may increase your chances of developing this form of arthritis. Arthritis at the base of the thumb is more common in women and usually starts after age 40.


The most common symptom of thumb basal joint arthritis is a deep, aching pain at the base of the thumb. The pain is often worsened with activities that involve any pinching movements such as opening jars, turning door knobs, and handwriting. As the disease progresses, patients may experience pain at rest and at night. Patients often note loss of pinch and grip strength.

In severe cases, progressive destruction and malalignment of the joint occurs and a “bump” develops at the base of the thumb. Thumb motion and the ability to pinch can grow limited and the space between the thumb and index finger narrows. The next joint up may hyper-extend to compensate.


The appearance of your thumb and the location of the pain are usually very helpful in identifying this condition. Applying longitudinal pressure along the thumb and twisting or grinding the basal joint is also helpful in reproducing symptoms. Although X-rays help confirm the diagnosis, symptom severity often does not correlate directly with the joint’s appearance on the X-ray.


Less severe thumb arthritis will usually respond to non-surgical care. Pain medication, topical agents, splinting, and limited use of corticosteroid injections may help alleviate pain. A hand therapist might provide a variety of rigid and non-rigid splints to support the thumb during activities.

Patients with advanced arthritis or who do not respond to non-surgical treatment may be candidates for surgical reconstruction. A variety of surgical techniques are available that can successfully reduce or eliminate pain and improve thumb position and function. Common surgical procedures include removal of arthritic bone and joint reconstruction, bone fusion or realignment techniques, and even arthroscopic procedures. A consultation with your doctor can help decide the best options for you.