Can Thumb Surgery Cause My Thumb Knuckle to Bend Backwards?

If you are living with thumb pain or rhizarthrosis, you may have heard about surgery to remove a small bone at the base of your thumb. This operation is called trapeziectomy. But what happens to your thumb after that bone is taken out?

A new study from 2025 examined what happens to the main knuckle of your thumb after surgery. The researchers found something important. Taking out the trapezium bone can lead to a problem where your thumb knuckle bends too far backwards. This is called hyperextension.

Here are three key points from this research:

• Removing the trapezium bone can cause your thumb knuckle to hyperextend.
• Common surgery techniques may not fix this bending problem.
• A special procedure using a small tendon can correct the hyperextension.

What Is Trapeziectomy and Why Does It Matter?

Let us start with the basics. Your thumb has several small bones. One of these bones sits right at the base of your thumb where it connects to your wrist. This bone is called the trapezium.

When thumb arthritis becomes very painful, doctors sometimes remove the trapezium bone. This surgery is called trapeziectomy. It can reduce pain. But what happens next?

You may be wondering why this matters. When the bone is gone, your thumb column becomes shorter. The thumb can telescope down. This changes how your thumb moves and balances.

What Did the Researchers Do?

The research team from Spain wanted to understand exactly what happens to the thumb knuckle after surgery. They used 10 cadaveric specimens. These are donated bodies used for medical research. The team tested six different surgical stages on each thumb.

Here is where it gets interesting. The scientists used special cameras to track how the thumb moved. They looked at the main knuckle of the thumb. This joint is called the metacarpophalangeal joint or MP joint for short.

The researchers measured the angle of the thumb knuckle during 10 cycles of bending and straightening. They recorded how far the thumb could bend forward and how far it could bend backward.

The Six Stages They Tested

Research shows that the team tested these stages in order:

What Happens to Your Thumb After Surgery?

According to this study, removing the trapezium bone caused a significant change. The thumb knuckle started bending backward too much. This is the hyperextension problem.

Let us look closer. When the trapezium was removed in stage 3, the thumb column became shorter. The first metacarpal bone telescoped down. This changed the balance of forces on the MP joint.

The angle in extension increased. This means the thumb knuckle bent further backward than normal. The range of motion also increased. The thumb could move through a bigger arc from bending forward to bending backward.

Does Standard Surgery Help the Problem?

Many surgeons perform a procedure called LRTI after removing the trapezium. LRTI stands for ligament reconstruction and tendon interposition. In this procedure, the surgeon uses a piece of tendon to rebuild support and fill the space where the bone was.

But here is the surprising finding. Studies indicate that LRTI did not fix the hyperextension problem. Even after stage 4, the thumb knuckle still bent too far backward. The angle in extension remained significantly increased compared to baseline.

The researchers also tested cutting a small tendon called the extensor pollicis brevis or EPB. This tendon helps straighten your thumb. Some surgeons thought cutting it might reduce the backward bending force.

According to research published in Hand journal in 2025, the EPB tenotomy also did not correct the hyperextension. The problem continued even after this step.

What Actually Worked?

The answer came in stage 6. The research team performed a special procedure called tenodesis. They used the extensor pollicis brevis tendon to reconstruct the volar plate. The volar plate is a strong ligament on the palm side of your thumb knuckle. It normally stops your thumb from bending backward too far.

Research shows that this stabilization procedure significantly corrected the hyperextension. After stage 6, the backward bending decreased. The thumb knuckle returned closer to its normal position.

The study authors concluded that trapeziectomy causes secondary thumb column shortening. This shortening favors the development of MP joint hyperextension deformity. The hyperextension is not corrected by LRTI or EPB tenotomy. It requires a stabilization procedure.

Common Questions

Will I get a hyperextended thumb after trapeziectomy?

According to this cadaveric study, trapeziectomy alone increases the risk of thumb knuckle hyperextension due to thumb column shortening. However, not every patient develops this problem. Your surgeon can assess your individual risk and may perform a stabilization procedure during surgery if needed.

What is LRTI surgery?

LRTI stands for ligament reconstruction and tendon interposition. In this common procedure, your surgeon uses a piece of tendon to rebuild support at the base of your thumb and fill the space left by the removed trapezium bone. This study found that LRTI does not prevent hyperextension at the thumb knuckle.

Can the hyperextension problem be fixed?

Research shows that a stabilization procedure using tenodesis can correct the hyperextension deformity. In this technique, a tendon is used to reconstruct the volar plate on the palm side of your thumb knuckle. This stops the thumb from bending backward too far.

What should I ask my surgeon before thumb surgery?

Ask your surgeon if they check for thumb knuckle stability during trapeziectomy. Ask if they perform any stabilization procedures at the MP joint. Discuss whether your thumb anatomy puts you at higher risk for hyperextension after surgery.

What This Means for You

This research gives us important information about what happens to the thumb after trapeziectomy. If you are considering surgery for thumb arthritis, it is helpful to understand these findings.

The study shows that removing the trapezium bone can lead to thumb knuckle hyperextension. Standard surgical techniques like LRTI may not prevent this problem. A stabilization procedure may be needed to keep your thumb knuckle in the right position.

Talk with your hand surgeon about these findings. Ask if they routinely check thumb knuckle stability during surgery. Ask if they perform any procedures to prevent hyperextension.

Remember that this was a laboratory study using cadaveric specimens. Your surgeon can explain how these findings apply to your specific situation. Every thumb is different. Your treatment plan should be tailored to your needs.

About This Site

We simplify medical science for people with thumb pain and rhizarthrosis. Every article on this site is based only on published scientific research. We translate complex medical studies into plain language you can understand. We never invent facts or add information that is not in the original research.

Explore more articles on our site to learn about diagnosis, treatment options, and what science tells us about thumb arthritis. Knowledge helps you have better conversations with your doctor and make informed choices about your care.

Important Information

This article is for educational purposes only. It is not medical advice. It does not replace the guidance of your doctor or hand surgeon. Always consult with a qualified healthcare professional about your specific condition and treatment options. Every person is different. What works for one patient may not be right for another.

Scientific Source

This article is based on research published by de Torres-Urrea, J.; Roda, O.; Molina-Molina, A.; Soto, V. M.; Simon-Perez, C.; Sanchez-Montesinos, I.; Hernandez-Cortes, P. in Hand journal in 2025.

https://doi.org/10.1177/15589447251339505