Get the facts

What is arthritis?
Joints are places in the body where bones join and move. The knee, elbow, and hip are all joints. The smooth white end of the bone is the part that moves against the other bone. This smooth white part is called “cartilage”. Just as your hair greys and thins cartilage also changes with age. With less cartilage, you may have pain, stiffness, and deformity.

What is arthritis at the base of the thumb?
One of the most common joints to develop arthritis with age is the base of the thumb. At the base of the thumb the first bone of the thumb—the metacarpal—moves against a small bone in your wrist—the trapezium (figure).


Figure: a healthy joint and arthritis.

What causes arthritis at the base of the thumb?
Everyone eventually gets arthritis at the base of the thumb. It’s a normal part of aging. It develops sooner in some families (genetic). It can also arrive sooner after fracture of the joint.