Basilar Thumb Arthritis (CMC arthritis)

Background

Basilar thumb arthritis, also known as CMC joint arthritis, is a common form of osteoarthritis in the thumb occuring in roughly 25% of men and 40% of women over the age of 75 years old.

The CMC joint tends to see high stress loads across the joint during use. Over time, the surrounding ligaments can become lax which increases the stress here and causes degeneration over time. This causes increased friction and pain in the joint. As the condition progresses, subluxations of the joint can occur along with progressive grip and/or pinch strength weakness.

Treatment

If conservative therapy fails and surgery is elected, Dr. Lee most often performs a CMC suspension arthroplasty. There are several surgical techniques for this condition. We perform this procedure due to it being simple, reproducible and provides excellent outcomes. In this procedure, the trapezium is excised and the flexor carpi radialis (FCR) is harvested proximally and split. It is then tunneled under the skin to the surgical site and tied to itself. The remaining tendon is anchovied and secured in the void left by the trapezium to maintain appropriate tension of the thumb and tendons. The joint and skin are then carefully closed and the patient is placed into a thumb spica plaster splint.

Post-op

The splint is left in place until the initial postoperative visit roughly at 2 weeks postop. After 2 weeks the splint will be removed and then the thumb will be placed in a spica cast for until 6 weeks postop. This will give your other digits freedom to move while the thumb is immobilized for those 6 weeks. The patient will undergo rehabilitation at 6 weeks postop to begin to increase ROM and strength in the wrist and hand.