If you have thumb pain or rhizarthrosis (arthritis at the base of the thumb), you want to know what treatments can really help. One study compared two surgeries for thumb arthritis: trapeziometacarpal prostheses (TMP) and trapeziectomy with ligamentoplasty (TL). It looked at which surgery might give your thumb better support and stronger grip.
Here are the main findings:
- A trapeziometacarpal prosthesis makes the thumb more stable and stronger, especially when the thumb joint bends backward a lot (extreme hyperextension).
- If the thumb stays unstable after surgery, grip strength is weaker.
- Keeping the thumb height longer helps with how well your hand works.
Let’s look at this study step by step.
Why does MCP hyperextension matter?
You might wonder why MCP hyperextension matters. MCP stands for metacarpophalangeal joint. This joint connects your thumb to your hand. When this joint bends backward too much, your hand can become less stable. This instability can make gripping or pinching objects hard, especially if you have thumb arthritis.
Doctors found that MCP hyperextension often makes thumb pain worse, especially when the thumb becomes shorter because of arthritis or surgery. This shortening may also affect how well your thumb and hand work.
Can a trapeziometacarpal prosthesis help your thumb?
Here is what the study did. It compared two surgeries for thumb arthritis:
- Trapeziometacarpal Prosthesis (TMP): This replaces the damaged joint with an artificial implant.
- Trapeziectomy with Ligamentoplasty (TL): This removes the damaged joint and stabilizes the area using ligaments.
Researchers found that the prosthesis better stabilizes the MCP joint, especially for people whose pre-surgery hyperextension was greater than 30 degrees. It also improved pinch strength, the ability to pick things up between your thumb and fingers.
These results show the prostheses restored thumb height better, which is likely why they help stabilize the joint.
How do thumb height and grip strength affect you?
Thumb height may seem small, but it changes how your thumb works. When the thumb becomes shorter after surgery, the MCP joint becomes less stable. This links to lower grip and pinch strength. If you use your hands a lot for tasks like carrying groceries or opening jars, weak pinch strength can make daily tasks harder.
The study also found that people who still had MCP hyperextension after surgery, whether they had a prosthesis or ligamentoplasty, had lower thumb height and weaker strength overall.
If keeping your thumb height and stability matters to you, the study suggests a trapeziometacarpal prosthesis might be the better option. But every person is different, and you should always discuss these options with your doctor.
What questions should you ask?
Is rhizarthrosis the same as thumb arthritis?
Yes. Rhizarthrosis is another name for thumb arthritis, which happens when the cartilage in the trapeziometacarpal joint wears down.
What is MCP hyperextension?
MCP hyperextension is when the base joint of your thumb bends backward too much, often leading to instability and pain.
What does a prosthesis do differently?
A trapeziometacarpal prosthesis replaces the damaged joint and may help stabilize the thumb better than removing the joint entirely.
Can this surgery make my thumb longer?
Yes! According to the study, the prosthesis restored thumb height, which contributed to better stability and functional outcomes.
What did the study conclude?
This study shows that choosing the right surgery for thumb arthritis can make a big difference in your recovery. A trapeziometacarpal prosthesis seems better at improving thumb stability and pinch strength than trapeziectomy with ligamentoplasty. It helps restore thumb height, which is important for grip strength and stability. But other factors may matter, so talk with your doctor to find what works best for you.
Is this information just for education?
This article is for educational purposes only and is not a substitute for professional medical advice. Always talk with your doctor to discuss treatment options that fit your needs.
Who wrote this study?
Degeorge, B.; Dagneaux, L.; Andrin, J.; Lazerges, C.; Coulet, B.; Chammas, M. (2018). Do trapeziometacarpal prosthesis provide better metacarpophalangeal stability than trapeziectomy and ligamentoplasty?