What is Thumb Arthritis?
Thumb arthritis, or basal joint arthritis, is the result of the wearing away of cartilage in the joint at the base of the thumb.
The basal joint allows your thumb to move around so you can perform small motor tasks. Without plenty of cushioning cartilage, the joints become rough and grind over each other when you move, causing more joint damage. It can also be caused by injury to the thumb.