CMC Arthroplasty Techniques: Tendon Transfer and More

Surgery to replace your thumb joint could involve a tendon transfer or an artificial replacement. There are also newer techniques that use a wire or suture as a sling to support your thumb.

As people age, the thumb joint becomes a common site of arthritis. The ligaments that hold the joint together can also loosen, causing it to slip. Or, the cartilage pad between the wrist joint (trapezium) and the joint at the base of the thumb (first carpometacarpal) can wear out.

This can cause stiffness, pain, and disability that a doctor can correct with carpometacarpal (CMC) arthroplasty, otherwise known as total thumb joint replacement.

To perform this surgery, a surgeon can use either a ligament from your body to cushion the joint or insert metal, silicone, or plastic prostheses. If they use a ligament, the procedure is known as ligament reconstruction and tendon interposition (LRTI). If they use a prosthesis, it's called a total joint replacement.

A doctor may also recommend variations of these techniques. This article reviews and compares various options for CMC arthroplasty.

During LRTI, a surgeon removes the damaged bone surfaces and part or all of the trapezium bone in your wrist. They then use your ligament to make a cushion to separate the remaining bones.

Doctors have performed this surgery for decades, often improving symptoms and thumb function. Still, there are downsides:

Total joint arthroplasty (aka total joint replacement) involves removing the damaged bone surfaces and replacing them with a prosthesis. This artificial replacement is made of either pyrocarbon or metal. They also use synthetic spacers to sit between the bones.

If you are younger and very active, with a lot of demand on the joint, a doctor may recommend synthetic spacers because metal prostheses can fail with heavy use.

Most CMC arthroplasties are successful and complication-free. Some conditions can increase your risk of complications, including diabetes and undergoing renal dialysis. But a 2019 study of 3,344 patients found very few complications in the first 30 days after surgery.

In a 2017 study, 89% of people who had total joint replacement were happy with the results.

Another option is hematoma distraction arthroplasty (HDA). This technique involves removing the trapezium and temporarily installing a wire (called a Kirschner wire or K-wire) to immobilize your thumb. Doctors keep the wire in for 4 to 6 weeks to allow the area to heal.

A 2021 study found HDA yielded better results than LRTI after 1 year. Still, the Arthritis Foundation notes that the procedure is "somewhat controversial." There isn't much consensus in the medical community yet regarding its effectiveness and perhaps a lack of specialists trained in this procedure.

Removing the trapezium does come with additional risks, such as a loss of pinch strength and a potentially shortened thumb.

Suture suspension arthroplasty (SSA), aka suture button suspensionplasty (SBS), aka TightRope, is a newer procedure similar to hematoma distraction. After removing the trapezium, a surgeon suspends the metacarpal of your thumb from the metacarpal of your index (pointer) finger with a suture attached to a button.

This technique is less invasive and has a shorter operating and recovery time. A 2023 study observed better long-term improvement in symptoms after SSA compared to LRTI. It also noted that the metacarpal was less likely to collapse after SSA.

A 2022 systematic review found that SSA and LRTI had similar outcomes, but more research was needed before drawing any conclusions.

What works best for you will depend on the following:

You’ll also need to consider whether your desired outcome is a realistic result of the specific procedure.

After surgery, joint replacement may give you better function and a more natural-looking thumb. But it is more expensive and more likely to create complications. The prosthesis is more likely to fail if you use your thumb joint often.

The following table offers a comparison between LRTI and total joint replacement:

HDA and SSA are simpler surgeries that may offer similar results. But there's less research available to support their effectiveness.

Talk with a specialized hand surgeon about which option may be best for you.