Carpometacarpal osteoarthritis is also known as osteoarthritis of the thumb or CMC joint arthritis. Symptoms can include pain and swelling. Treatment typically includes icing, splinting, and medication.

Carpometacarpal osteoarthritis occurs when the cartilage at the base of the thumb starts wearing away. Aging or excessive use of the joint may cause this to occur. Without the cartilage, the bones of the joint start rubbing against each other, and this can cause inflammation and other symptoms, leading to pain and discomfort.

This article discusses the symptoms and causes of carpometacarpal osteoarthritis in more detail. It also looks at treatment options, when surgery may be necessary, how doctors diagnose the condition, and more.

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Symptoms of carpometacarpal osteoarthritis can vary. People with the condition may experience:

  • pain
  • swelling
  • a reduced ability to pinch or grip with the thumb
  • loss of strength in the thumb and wrist
  • loss or difficulty in movement of the thumb and wrist

Learn more about osteoarthritis.

Cartilage acts as a cushion to reduce the friction between the bones in the joint. Aging and the ongoing use of the thumb and its linked joint may cause the natural wear of the cartilage and the onset of osteoarthritis.

A significant injury or a fracture may cause damage to the cartilage, increasing the risk for this condition.

Using this joint frequently, such as for occupational reasons, may also increase the risk of the onset of carpometacarpal osteoarthritis.

Learn more about cartilage damage.

In its early stages, a person could treat carpometacarpal osteoarthritis with home remedies and medication. These treatments may include:

  • applying ice or a cold compress for 5–15 minutes to the joint several times daily
  • wearing a splint to limit the movement of the joint and allow it to rest
  • taking anti-inflammatory medication to reduce pain and swelling

Recently, doctors also started using intra-articular injections of medications, such as hyaluronic acid and platelet-rich plasma, to improve the symptoms of carpometacarpal osteoarthritis. However, more research is necessary to confirm their long-term effectiveness. Learn more about joint injections.

Carpometacarpal osteoarthritis is a degenerative and progressive condition, and over time, these treatments may start losing their effectiveness. When nonsurgical treatment is no longer effective, doctors may recommend surgical treatment.

There are various surgical options to help treat carpometacarpal osteoarthritis. Doctors can recommend the most appropriate option according to a person’s condition.

One approach is fusing the bones in the joint to reduce the rubbing between them. This solution typically reduces the pain and helps improve the individual’s ability to pinch with their thumb. However, because the bones are fused, a person may have reduced thumb mobility.

Another option would be to remove part of the joint and suspend the thumb by using either a tendon in the wrist or a medical device. This alternative typically provides pain relief and usually allows regular and free movement of the thumb.

After surgery, people typically need to undergo rehabilitation. This may last 4–8 weeks, depending on the surgical procedure.

Learn more about thumb arthritis surgery.

Doctors usually start the diagnosis of carpometacarpal osteoarthritis by taking a full medical history. They will also ask questions about any occupational or routine tasks that may cause overuse of the carpometacarpal joint.

The doctor may also ask questions about symptoms and perform a physical examination.

To confirm the diagnosis, healthcare professionals may also recommend an X-ray. This can help assess the health of the cartilage and its potential deterioration.

If a person experiences symptoms of carpometacarpal osteoarthritis, including swelling and pain in the thumb, they may consider contacting a doctor.

Doctors can perform a physical examination and recommend additional tests to assess the health of the joint when necessary. They can also recommend the most appropriate treatment according to a person’s circumstances.

Carpometacarpal osteoarthritis may develop in people of any age. However, it is more common in those over the age of 40 years.

People assigned female at birth also have a higher risk of having carpometacarpal osteoarthritis than those assigned male at birth.

Having sustained an injury or a fracture to the joint may also increase the chance of developing carpometacarpal osteoarthritis in the future.

Carpometacarpal osteoarthritis may cause pain and weakness in the affected joints. It may also cause stiffness and reduced mobility.

Surgery for treating this condition is typically safe. Around 1.3% of people undergoing surgery for carpometacarpal osteoarthritis develop complications. The possible complications of these procedures may include:

The doctor will be able to discuss the possible complications and what steps are necessary to reduce the risks.

To help prevent carpometacarpal osteoarthritis, people can minimize the risk of trauma or fractures in the thumb and its surrounding joint. This might include wearing protective gear or using appropriate precautions when moving or lifting heavy objects.

There are other steps a person can take to reduce the risk of carpometacarpal osteoarthritis or slow down its progression. These include:

  • maintaining a moderate weight
  • getting enough physical activity or exercise
  • controlling blood sugar, as high blood sugar levels can affect the stiffness of cartilage

It is best for a person to contact their doctor for more advice if they have concerns about carpometacarpal osteoarthritis.

Carpometacarpal osteoarthritis may develop when the cartilage in the thumb wears away or after an injury or fracture. People with this condition may experience pain and swelling in the joint and reduced mobility.

Carpometacarpal osteoarthritis is a treatable condition that people can manage with nonsurgical treatment in its early stages. This may include icing the area, wearing a splint, and taking anti-inflammatory medication.

Thumb osteoarthritis is a progressive and degenerative condition. When nonsurgical treatment is no longer effective in relieving carpometacarpal osteoarthritis symptoms, doctors may recommend surgery to relieve pain and improve the general health of the joint.