Carpometacarpal (CMC) Arthritis Symptoms & Treatment

The carpometacarpal (CMC) joint, also known as the basal joint, connects the base of your thumb to your wrist. The CMC joint allows your thumb to move in various directions and grasp objects.

Arthritis of the CMC joint is a degenerative condition that can lead to severe pain, stiffness, and loss of motion in your thumb, making it difficult to complete daily tasks, like turning doorknobs. CMC joint arthritis is a common condition, especially among women and older adults.

Carpometacarpal arthritis occurs when the smooth cartilage that covers the ends of the bones in the CMC joint breaks down–this process is known as osteoarthritis. When this happens, the bones can rub together, causing irritation, swelling, and pain.

Certain factors may increase your risk of CMC arthritis, including:

• Being female
• Being over 40 years of age
• Certain hereditary conditions, such as malformed joints
• Diseases that change the typical structure of cartilage, such as rheumatoid arthritis

Injuries, including thumb fractures and sprains, occasionally lead to CMC arthritis years later. When this occurs, it’s called posttraumatic arthritis.

Sports that are most likely to lead to thumb injuries that may then lead to post-traumatic CMC arthritis include:

• Skiing
• Baseball
• Volleyball
• Basketball
• Football
• Hockey
• Rugby

Thumb pain is the first and most common symptom of CMC arthritis. The pain usually occurs at the base of your thumb when grasping an object or when using your thumb to apply force. Other signs and symptoms of CMC arthritis may include:

• Stiffness, tenderness, and swelling at the base of the thumb
• Decreased range of motion of the thumb
• Weakness when grasping or pinching objects
• Deformity of the joint at the base of your thumb

See your doctor if you have persistent swelling, stiffness, or pain at the base of your thumb that worsens and interferes with functioning.

During your appointment, your doctor will ask about your symptoms and examine your thumb, checking for swelling, areas of tenderness, and examining range of motion. Your doctor may hold your CMC joint while moving your thumb to see if it produces pain, a grinding sound, or a gritty sensation that may indicate the cartilage has worn down.

Your doctor may also order X-rays to check for signs of thumb arthritis, such as bone spurs; degenerative damage to the cartilage; and decreased joint space.

Treatment for early-stage CMC arthritis usually involves a combination of non-operative approaches to reduce swelling and relieve pain, including:

• Avoiding activities that aggravate the thumb
• Topical medications
• Non-steroidal anti-inflammatory drugs (NSAIDs), like ibuprofen or naproxen sodium
• Splinting the thumb to restrict movement and relieve pain
• Corticosteroid injections

Try these exercises to help address your condition:

Below is a PDF of the exercise program.

Carpometacarpal Arthritis 

If CMC arthritis is severe, or conservative treatment fails to relieve your symptoms, your doctor may recommend surgery. Surgical options for thumb arthritis include:

• CMC joint fusion: A procedure that permanently fuses the bones of the CMC joint to avoid them rubbing together.
• Osteotomy: A procedure that involves cutting the bones to reposition and realign the bones of the CMC joint.
• Trapeziectomy: A procedure that involves removing the trapezium, one of the small bones that form the wrist. The goal of this surgery is to create more space for the thumb to move.
• Joint replacement: Also called, CMC arthroplasty, removes all or part of the joint and replaces it with a tendon graft.

Surgery for CMC arthritis is performed on an outpatient basis, meaning that you can go home on the same day as your procedure.

CMC arthritis is a chronic condition and symptoms may come and go over time. To relieve pain and improve mobility, you can try home remedies like purchasing modified hand tools and applying hot and cold compresses.

If you’ve had surgery, you can expect to wear a thumb cast for 3 to 4 weeks, followed by a splint for 4 to 6 weeks. It usually takes 6 to 8 weeks to regain mobility in your thumb, but full recovery can take up to several months.