Carpometacarpal Osteoarthritis

Osteoarthritis (OA) is the most common form of arthritis and affects mainly the joint’s cartilage and surrounding bone tissue. OA can occur in any joint – knees, hips, shoulders, and even the hands or fingers, called Carpometacarpal Osteoarthritis. The prevalence of thumb carpometacarpal osteoarthritis is 7% for men and 15% for women. Because of the rarity of ensuing disability, carpometacarpal osteoarthritis of the thumb is likely to be underdiagnosed in clinical practice. 

The thumb is the most important digit of the hand and the most important joint in the thumb is the carpometacarpal joint (CMC joint). Large demands are placed on the CMC joint during activities of daily living.  The CMC joint is a saddle joint which allows a wide range of motion, but can become unstable, secondary to osteo and rheumatoid arthritis. In severe OA, the cartilage can become so thin that it no longer covers the joint surfaces, and damage is caused to the bone ends by them grinding against each other during movement. This can, over time, change the shape of the joint creating a deformity, as the joint is no longer held in its natural position.


Arthritis develops frequently at the CMC joint as a result of cumulative trauma. Sports, hobbies, and occupation can all contribute to wear and tear on the joint. The prevalence of CMC arthritis is 3 to 4 times higher in women than men. On average, 1 in 20 elderly women had consulted a physician for CMC osteoarthritis (Jenifer Moriatis Wolf et al. Arthritis Care Res. 2021 Jun.)

cmc joint osteoarthritis xray

Common Symptoms of Osteoarthritis in the CMC joint are:

  • Pain: CMC OA pain is typically perceived as a sharp pain and/or consistent ache near the base of the thumb, at the joint. This pain is usually worsened by movement or use and relieved by resting.
  • Reduced grip strength: Patients with CMC OA may find it difficult to grip or pick up objects.
  • Stiffness: Generally presents in the mornings or after extended periods of rest.
  • Swelling: Around the joint itself at the base of the thumb.
  • Muscle Weakness and Instability
  • Deformity: Advanced stages of CMC OA can cause the resting position of the thumb to evolve over time.

The good news is there are many conservative options that a certified hand therapist can use to treat and improve CMC joint pain. Improving biomechanics at the thumb can reduce stress across the joint with activities such as gripping and pinching.  Unfortunately, pain and stiffness leads to a cascade of altered mechanics that can increase compression of the CMC joint and cause arthritic changes at the neighboring joints in the hand.  

Adaptive equipment can decrease loading of the joint during common and frequent ADLs. There are numerous items available to improve tasks that have become painful or difficult at home and work. 




Pre-manufactured braces can be used to protect the thumb during normal use.  Your hand therapist can assist in choosing the correct brace and appropriate size.  



Lastly a hand therapist can design a specific program including manual stretching, joint mobilization, strengthening, functional retraining, and custom splinting.  



If conservative treatment does not improve complaints of pain and loss of function, your Axes certified hand therapist can refer you to a hand or orthopedic surgeon to discuss the possibility of injections or surgery.  A cortisone injection into the CMC joint can sometimes improve your pain. Results are variable and can improve pain for several months.  Thumb CMC arthroplasty is an option for thumb arthritis.  Surgeons have many successful procedures that can restore normal thumb mechanics and decrease pain.  Following surgery, protective splinting and physical/occupational therapy will be prescribed to assist in your recovery.  

Are you experiencing symptoms of Osteoarthritis or other joint pains? Axes is here for you. With 13, soon to be 14, Greater St. Louis area locations and an expert staff – we want to be a part of your healthcare team. Request an appointment online today!

To schedule an appointment with any of our expert physical and occupational therapists, request an appointment online today.