Understanding Carpometacarpal Osteoarthritis

The base of the thumb where it meets the hand is called the carpometacarpal (CMC) joint. This joint lets the thumb move freely in many directions. It provides strength so the hand can grasp and grip.

A smooth tissue called cartilage lines and cushions the bones of the CMC joint. Using the thumb puts stress on the joint. Over time, this can lead to the breakdown of the cartilage in the joint. This is known as osteoarthritis. With this condition, bones of the joint may rub together. They may become irritated and rough. This keeps the joint from moving smoothly and can lead to pain.

Palm view of hand showing metacarpal and carpal bones.

How to say it

KAR-po-met-uh-KAR-puhl

What causes CMC joint osteoarthritis?

This type of osteoarthritis is mainly caused by years of using the hand and thumb. The condition may be more likely if you:

Regularly do things that put great stress on the thumb joint
Have had previous thumb injuries
Have weak or loose tissue in the thumb

Symptoms of CMC joint osteoarthritis

Symptoms commonly include:

Thumb pain that may get worse with pinching or gripping
Thumb weakness
Sounds of grinding or popping in the thumb joint
Base of the thumb that's swollen or stiff

Treatment for CMC joint osteoarthritis

Osteoarthritis is a long-term (chronic) condition. Treatment focuses on managing symptoms. It may include:

Taking prescription or over-the-counter medicines to help reduce pain and swelling
Using a brace to rest and support the thumb joint
Using hot or cold therapy to help relieve pain
Learning and practicing ways to reduce stress on the thumb joint
Using devices that help protect the joint such as jar openers, pen grips, and spring-action scissors
Doing physical therapy and exercises to help improve the flexibility and strength of the hand and thumb
Getting shots of medicine into the joint to help relieve symptoms for a time

If these treatments don’t do enough to relieve severe pain, you may need surgery. There are several types of surgery. Your healthcare provider will talk with you about options if needed. In general, the goal is to ease pain and help you to be able to use the hand.