What Is A Fusion?

A fusion is a surgery done to stop two things: motion and pain. A fusion creates a solid bone where a joint used to be. In this article, I’ll share an example of a common fusion surgery I do to cure finger pain.

Why would someone want a fusion surgery?

A fusion (also called an arthrodesis) is almost always done for arthritis. It’s a cure for arthritis. Fusing a joint cures the arthritis forever and stops pain.

Because the pain of arthritis comes from a worn out joint grinding on itself, if you stop the grinding, you stop the pain.

Patients with arthritis in the fingers try many treatments – from splints, to steroid shots, to medicines, and even surgeries to replace joints and repair bones.

When all these stop working, a fusion is the last option to try in most cases. It’s a good, reliable operation that’s been working for centuries.

How does a fusion work?

In a fusion surgery, the surgeon opens up the joint, exposing the worn out joint surfaces. He uses tools (scraping tools and often a burr) to expose raw spongy bone on either side of the old joint.

Sometimes bone graft is packed into this space, and the two bones are held together by some type of hardware, like a screw or wires.

In this example, you can see an xray of a finger joint fused together by a single screw.

fingertip dip fusion

The hardware keeps the two bones still and squeezed next to each other while they heal. Eventually solid bone grows across the junction between the two bones, forming a solid bridge of hard, normal bone.

How long does it take for a fusion to heal?

Because I’m putting two bone surfaces together to let them heal, fusions heal like a fractured bone. Instead of two broken bone fragments healing together, there are two normal bones healing together.

This process takes about six weeks in a finger.

Signs of healing include new calcified bone on an xray – growing across like a bridge between the bones, and no tenderness when the patient pushes on the old joint.

Usually patients can use the finger for light activities while the fusion is healing – typing, writing, getting ready in the morning. The screw is strong enough to withstand some light daily activity.

How does a fusion cure arthritis?

In the process of fusing the joint, the old joint surfaces are removed. Therefore, technically, there isn’t a joint there anymore.

Without a joint, you can’t have arthritis, so it’s gone forever!

What’s the big downside to a fusion surgery?

No motion.

The motion of the fused joint stops forever. The joints around the fused joint may move normally, but the fused bones become permanently stiff.

A fusion is a tradeoff between motion and pain. You get stiff, but the pain goes away forever. The happiest patients after a fusion surgery are patients who had daily pain in the finger before surgery, even with light activities.

Another thing that surprises patients is that the finger is still somewhat enlarged or lumpy after the fusion. This is common, and often cannot be corrected completely. However, the finger should be straight, not twisted, and pain-free once it’s healed.

What will the finger look like after the surgery?

Here’s a video of one of my patients with a fused, pain-free pinky finger joint after healing. The finger moves at the MCP and PIP joints, but the end knuckle doesn’t move at all.