The universal joint at the base of the thumb, between the metacarpal and trapezium bones, often becomes arthritic as people get older. It is osteoarthritis, which is loss of the smooth cartilage surface covering the ends of the bones in the joints. The cartilage becomes thin and rough, and the bone ends can rub together. osteoarthritis can develop at any age, but usually appears after the age of 45. It may run in families, and it sometimes follows a fracture involving the joint many years before.
- Pain at the base of the thumb, aggravated by thumb use.
- Tenderness if you press on the base of the thumb.
- Difficulty with tasks such as opening jars, turning a key in the lock etc.
- Stiffness of the thumb and some loss of ability to open the thumb away from the hand.
- In advanced cases, there is a bump at the base of the thumb and the middle thumb joint may hyperextend, giving a zigzag appearance.