The thumb carpometacarpal, or CMC, joint sits where the thumb meets the wrist. It allows the thumb to move across the palm, but that mobility also exposes it to substantial load during pinching, opening containers and turning keys.
Thumb-base pain can have more than one cause. The examination looks at the CMC joint, nearby tendons, the wrist and sensation before treatment is chosen.
Symptoms of thumb-base arthritis
- Pain at the base of the thumb with pinch or grip
- Difficulty opening jars, fastening clothing or turning keys
- Swelling, tenderness or a change in the shape of the thumb base
- Reduced pinch strength or a feeling that the thumb is unstable
First steps in treatment
- A thumb-supporting brace for painful activities or rest
- Activity changes and tools that reduce pinch force
- Hand therapy to protect motion and build useful strength
- Medication or a selected injection when appropriate for the individual
When surgery enters the discussion
Surgery is considered when pain and loss of function remain substantial despite nonsurgical care. The operation depends on the joint surfaces, alignment, age, activity demands and whether nearby joints are also involved.
Different procedures trade pain relief, stability, recovery time and motion in different ways. A consultation should explain the specific problem and the expected limitations rather than treating every thumb-base X-ray the same way.
Protecting the thumb after treatment
Whether care is nonsurgical or surgical, the aim is a thumb that can pinch and grasp in a useful way. Therapy and gradual return to loading help the hand adapt while swelling and sensitivity settle.
Sources and further reading
Frequently asked questions
Does everyone with thumb CMC arthritis need surgery?
No. Bracing, therapy, activity changes and selected injections help many people. Surgery is considered when pain remains limiting despite those options.
Why does opening a jar hurt so much?
Opening a jar combines pinch, grip and rotation, which place high load across the thumb-base joint. The same load can also aggravate nearby tendons, so the exact source of pain should be examined.