Basal joint arthritis is one of the most common forms of thumb arthritis.
Also called basal thumb arthritis, this is arthritis in the basal joint at the base of the thumb. The basal joint is where the metacarpal bone of the thumb meets the trapezium bone in the wrist. This condition can be very disabling because use of the thumb is necessary for nearly every manual, from writing to opening a jar to buttoning a shirt.
Like all other forms of osteoarthritis, basal thumb arthritis develops when the cartilage between the bones of the joint wears away. In basal joint arthritis, the cartilage degeneration causes the metacarpal bone to slip out of its joint with the wrist. Arthritis in this location generally begins to develop in people aged 40 to 50 years old. Often it is visible in an X-ray before a person experiences any symptoms.
The most frequent symptom is a dull aching pain at the base of the thumb that gets worse with activity and better with rest. People may also have swelling and tenderness at the base of the thumb, loss of strength in gripping or pinching, loss of motion, and morning pain and stiffness. For reasons that remain unclear, the degree of inflammation and associated pain can fluctuate. The resulting incorrect alignment of the metacarpal bone often creates the appearance of a bump near the wrist.
Conservative treatments include icing the joint, taking anti-inflammatory medications, wearing a supportive splint, or getting cortisone injections into the joint. Surgical options include fusing the bones that make up the basal joint or reconstructing the joint.
Conservative methods are always preferred to surgery, and they are usually successful for most hand disorders. However, if conservative methods are not working for particular case, surgical methods are recommended as a last resort.
Get a deeper dive on basal joint arthritis and learn about other conditions of the hands.
Learn about physical therapy for basal joint arthritis and hand surgery at Hospital for Special Surgery.