For Patients: CMC Thumb Joint Replacement for Arthritis

For those suffering from painful thumb CMC osteoarthritis, everyday tasks become painful, if not impossible. Until now, treatment options have come with trade-offs, often compromising functional movement or grip strength for pain relief. The new ZEPART® thumb joint implant is designed to restore natural, pain-free thumb movement without compromise.

CMC Osteoarthritis is arthritis at the Carpometacarpal (CMC) joint of the thumb, between the 1st metacarpal and the trapezium carpal bone. Symptoms include:

  • Pain at the base of the thumb, particularly when pinching or gripping.
  • Swelling, tenderness, at the CMC joint.
  • Stiffness in the CMC joint, along with losses in flexibility and dexterity.
  • Loss of thumb grip/pinch strength.
  • In severe cases, complete misalignment of the joint and spreading of arthritis to nearby carpal bones.

The thumb CMC joint is a saddle joint with complicated movement patterns. As such, CMC arthritis can be incredibly debilitating to patients and may result in significant difficulty performing simple tasks.

There are four generic stages of symptomatic CMC osteoarthritis:

Minor with some cartilage wear
Mild with more degradation and noticeable stiffness
Moderate with cartilage erosion causing discomfort during everyday activities
Severe with mostly degraded cartilage and severe pain

Many risk factors lead to the development of arthritis at the thumb CMC joint. A lifestyle involving high compressive forces through the joint via grip and pinch movements may result in degenerative CMC osteoarthritis. Other risk factors include being of female biological gender, having increased BMI, having Ehlers-Danlos syndrome or similar genetic syndromes that predispose osteoarthritis, genetic family history, a history of high-impact injury to the joint, and age. This form of arthritis is common, particularly in elderly women.

As the pain grows intolerable and mobility is severely limited, surgical joint replacement with the ZEPART implant offers a return to a normal lifestyle. The implant is expected to be available to surgeons as soon as 2026. If you’re evaluating treatment options for thumb CMC osteoarthritis, ask your physician if the ZEPART implant could work for you.

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