What is CMC Joint Fusion?

Joint fusion is a surgical procedure that is done to fuse the surfaces of your thumb metacarpal with the trapezium bone so as to prevent them from moving and causing pain. This is usually carried out on younger patients who require more thumb strength to do their jobs (for example, carpenters).

Once this fusion is done, the pain will go away. Although it will loosen the joint movement, they would still give the capability to grasp and pinch. It’s to be noted that the joint fusion will be prescribed only when all other forms of treatments, including the joint replacement, haven’t worked.

During the operation:

This surgery can prolong to up to 90 minutes. It may be done under a general anesthetic or a local anesthetic. Once you get the anesthesia, the surgeon will ensure that the skin in your hand is free from infections by cleaning it with a germ-killer.

A cut will be made on the side of your thumb just above your CMC joint. The joint capsule that surrounds the CMC joint will then be opened so as to make the joint surfaces visible. Then, the articular cartilage will be removed. A tool will be used to void the end of your thumb metacarpal so as to create a socket. Then, the surface of your trapezium will be made into a rounded cone in such a way that it fits into the created socket.

The surgeon will keep a metal pin along the center of both the bones to connect the cone and socket comfy together. The soft tissues above the joint will then be fused back together. Once this is done, the forearm and hand will be placed in a cast until these bones completely join together. It will take about six weeks for this to happen.