What are the symptoms and signs of arthritis at the base of the thumb?
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 pinch, including opening jars, turning door knobs or keys, and writing. As the disease progresses, patients may experience pain at rest and at night, and patients often note loss of pinch and grip strength. In severe cases, progressive destruction and mal-alignment of the joint occurs and a “bump” develops at the base of the thumb, which is caused by the thumb metacarpal moving out of position in relation to the trapezium. At this point, thumb motion becomes limited and the space between the thumb and index finger narrows, making pinch activities difficult (see Figure 2). The next joint up may hyper-extend to compensate. How is the diagnosis made for arthritis at the base of the thumb? The appearance of the thumb and the location of the pain are usually very helpful in identifying this condition. Applying longitudinal pressure a
