Thumb Arthritis (CMC): Protecting the Joint You Use Most

Why the thumb wears out first

The carpometacarpal (CMC) joint is a saddle joint that trades stability for mobility. Every pinch you make loads that joint with many times the force at your fingertips. Over decades the cartilage thins and the joint becomes painful and unstable.

A three-part approach

• Custom thumb CMC orthosis: a hand-molded support that stabilizes the base of the thumb while leaving the fingertip free, worn during aggravating tasks or at night.
• Joint protection training: changing how you grip, lift, open and carry so the same day's work costs the joint less.
• Targeted strengthening of the first dorsal interosseous and opponens muscles, which act as dynamic stabilizers for the joint.

Everyday changes that reduce load

• Use a jar opener or an electric can opener rather than a tight pinch grip.
• Carry bags on the forearm or shoulder, not hooked on the thumb.
• Switch to lever-style door handles and larger-diameter pens and tool grips.
• Push doors and drawers with an open palm instead of pinching handles.

If you are considering surgery

Conservative care is often tried first and can postpone or avoid surgery. If a CMC arthroplasty is performed, structured post-surgical therapy protects the reconstruction and rebuilds pinch strength on a careful timeline.

Frequently asked

Will an orthosis make my thumb weak?

Used as prescribed — during aggravating activities and at night — an orthosis reduces pain so you can strengthen the stabilizing muscles. Strength is built through the exercise program, not lost to the splint.

Is thumb arthritis reversible?

Cartilage loss is not reversible, but pain, function and grip strength very often improve substantially with orthotic support, joint protection and strengthening.