Base of the Thumb Arthritis

Osteoarthritis of the base of the thumb, also known as first carpometacarpal joint (CMC) or basilar joint arthritis, is the second most common form of arthritis in the hand. It involves the wear and tear of the cartilage between the first metacarpal (the long bone of the palm that connects the wrist to the thumb) and the trapezium (one of the small bones that make up the wrist joint). Also known as the 1st CMC joint, it is exceptionally important and is what makes us “human” – it is the joint responsible for the “opposable thumb”. It is, therefore, very susceptible to deterioration (since we use it so often) and can cause significant pain and loss of function when it does not work properly.  The pain initially occurs sporadically and, as the joint degenerates further, can become more persistent and more difficult to live with. Eventually, the joint mechanics will deteriorate and other joints in the thumb can become affected, leading to a “Z deformity” of the thumb.

Carpometacarpal Joint Arthritis Treatments

The goal in treating your CMC thumb arthritis is to improve your pain while preserving and obtaining as much motion as possible. 

Treatments for Mild CMC Thumb Arthritis



Your doctor may recommend over-the-counter NSAIDs, such as Ibuprofen or naproxen to reduce inflammation and pain. 

Physical Therapy

This may involve joint protection techniques, assistive devices, heat or cold applied locally to relieve stiffness and swelling, and exercises to maintain strength and function.

Topical Creams

Topical anti-inflammatory or capsaicin creams can provide localized pain relief.


Corticosteroid injections can provide temporary pain relief. 

Moderate to Severe CMC Thumb Arthritis Treatments


CMC Joint Fusion

Damaged surfaces of the CMC joint are removed and the two bones are permanently fused together to eliminate painful motion.

CMC Joint Replacement

The trapezium bone is removed and replaced with an implant, while a stem is placed in the thumb metacarpal bone for stability. This artificial joint aims to restore range of motion.

Partial Trapeziectomy

Just the thumb-side portion of the trapezium bone is removed to decompress the arthritic CMC joint and allow the thumb metacarpal to move better.

Full Trapeziectomy with Ligament Reconstruction and Tendon Interposition 

The full trapezium bone is removed at the base of the thumb metacarpal, and the joint is reconstructed using a nearby tendon to maintain strength and stability.


A small needle is inserted into the joint to ablate the nerve endings, typically with radiofrequency energy. This disrupts the small nerve branches that innervate the joint, reducing the transmission of pain signals.

Why Patients Trust the Center for Hand & Upper Extremity Surgery

With decades of experience specializing exclusively in hand and upper limb conditions, the Center for Hand & Upper Extremity is the premier destination for customized treatment plans and expert surgical care. Patients trust the Center's board-certified plastic and orthopedic specialists to deliver high-quality, compassionate care and achieve optimal outcomes for hand and wrist arthritis, injuries, and other conditions.

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When to Seek Medical Attention

If thumb pain, stiffness, or weakness is making normal activities like grasping objects difficult, it's time to get evaluated for first CMC arthritis. Patients should also seek medical attention if they notice swelling, deformity, or instability in the thumb joint, or if pain persists for over 2 weeks despite rest, ice, and over-the-counter medication. Getting CMC arthritis treated early maximizes the chance of restoring thumb function and avoiding permanent joint damage or disability.


What causes CMC thumb arthritis?
Our joints are the intersection where two bones meet and articulate, allowing the joint to move. All joints throughout the body are lined with a slick substance known as cartilage, which allows for the smooth movement of one bone relative to another. Arthritis is a generic term that indicates the degeneration of this cartilage, which can lead to “bone on bone” motion that causes significant pain and deformity. There are two main types of arthritis that can occur:

Osteoarthritis, also known as “wear and tear” arthritis, is a process that occurs with aging and involves the deterioration of cartilage with increasing usage. 

Inflammatory arthritis is an autoimmune phenomenon in numerous inflammatory conditions where the body’s immune system attacks the cartilage and causes joint destruction.
What are the risk factors for developing thumb CMC arthritis?
The risk of developing arthritis increases with age, as joint cartilage naturally wears down over time. Other key risk factors include joint injury, obesity, genetics, and occupations involving repetitive motions. Additionally, certain diseases like diabetes, gout, and autoimmune disorders can increase susceptibility to arthritis through systemic inflammation or joint damage.
How is thumb CMC arthritis diagnosed?

The diagnosis of basilar joint arthritis is made by reviewing your medical history, a physical examination, and X-rays. Additional tests may include a CT scan to get high- level detail of the arthritis and determine the best course of treatment.

HUES Surgeons

Don’t Let Basilar Thumb Arthritis Slow You Down.