Thumb Arthritis: Basilar Thumb Degenerative Joint Disease

Posted on Friday, June 21, 2019 in Videos

Dr. Anthony Berni of Signature Orthopedics - St. Charles explains degenerative joint disease and how he goes about reliving it.


I'm here today to talk about basilar thumb degenerative joint disease also known as thumb CMC joint degeneration. This is a common condition that affects many people - particularly people who've done manual work; others that have genetic predisposition to arthritis of the base of the thumb.

Basilar thumb joint

People say "where is that basilar thumb joint?" It's right at the base of the thumb where the thumb metacarpal joins up with the wrist bones. This condition can present as bone spurs at the base of this thumb where this normally articulates and moves freely.

We have a lot of degrees of freedom of this joint because this joint is unique in the sense that it is a saddle joint. It's where two "horse saddles," if you will, meet up with each other and allow for range of motion in any plane.

Saddle joint illustration

There's many ways to treat this arthritis. Some of the more modern approaches are implant arthroplasties. What does that mean? This is a metal device that replaces that joint.

We have a model of it here which shows that this is, in fact, a saddle prostheses and you can see that this mimics what the bone used to look like, however it no longer has bone contacting bone. We have bone from the carpus (the carpal bone) beneath that rubbing smoothly on this saddle allowing normal joint motion.

Thumb model with implant

This restores the kinematics of the joint quite nicely; does not sacrifice any tendons in the forearm in the process.

People have a very quick recovery, a quick return to function, and very satisfying results.