If you have pain at the base of your thumb, you may have a condition called rhizarthrosis. That is a big word that simply means arthritis in your thumb joint. This article is about a medical study that tested a special gel injection. The gel is called hyaluronic acid. Researchers wanted to see if one shot of this gel could help people with thumb pain feel better and use their hands more easily.
Here are three things you should know:
- The study looked at twenty people with thumb arthritis who got one injection of hyaluronic acid.
- After six months, pain dropped by 77 percent on average.
- There were no side effects or problems reported.
Key Findings at a Glance
- Pain dropped by 77% over six months after one injection
- 80% of patients were able to use their hands normally again
- All patients said they were happy with the treatment
- No side effects or problems were reported
- The treatment worked for people with moderate to severe thumb arthritis
What is rhizarthrosis?
Rhizarthrosis is the medical name for arthritis at the base of your thumb. This is where your thumb bone connects to your wrist. Doctors also call it osteoarthritis of the first carpometacarpal joint. That joint is like a hinge that lets your thumb move in many directions.
Research shows that this condition is very common. About 15 out of every 100 women over age 50 have it. About 7 out of every 100 men over 50 have it. It happens more often as people get older.
You may be wondering why this matters. Many people with this kind of thumb pain do not go to the doctor. They think nothing can help. But this study shows that treatment can work very well.
Who was in this study?
The doctors studied twenty people at a hospital in Spain. The study happened between January 2020 and June 2022. Most of the patients were women. In fact, 80 percent were women. The average age was 61 years old.
Let us look closer at who these people were:
- 80 percent had arthritis in both thumbs, not just one
- 70 percent had moderate to severe arthritis based on x-rays
- 65 percent had other health problems like hand arthritis, weak bones, or diabetes
- 80 percent had already tried this same type of injection before
According to this study, the researchers used something called the Kellgren-Lawrence grade to measure how bad the arthritis was. This is a system doctors use when they look at x-rays. Grade three and four mean moderate to severe. Most patients in this study had that level.
What did the researchers test?
The doctors gave each person one injection of a gel called Adant. This gel contains hyaluronic acid. Hyaluronic acid is a substance that naturally lives in your joints. It acts like oil in a machine. It helps the joint move smoothly without grinding.
The doctors gave either 1 milliliter or 2 milliliters of the gel. A milliliter is a tiny amount, about the size of a small grape. They put the gel directly into the thumb joint with a needle. This is called an intra-articular injection. That means inside the joint.
Then they followed each person for six months. They asked questions about pain and what the person could do with their hands. They asked if the person could turn a key, hold things tightly, or button a shirt.
What did they find out?
Here is where it gets interesting. The results were very good.
Pain went down a lot
The doctors used something called a Visual Analogue Scale to measure pain. This is a simple tool. Patients mark on a line how much pain they feel. Zero means no pain. Ten means the worst pain you can imagine.
According to this study, the average pain score dropped by almost 6 points over six months. That is a 77 percent reduction in pain. This change was very strong in the statistics. Scientists were very sure it was real and not just luck.
Even better, 35 percent of patients had pain drop by 80 percent or more. The rest had pain drop by 70 to 79 percent. Every single person got better.
People could use their hands again
Pain is not the only problem with thumb arthritis. It also makes it hard to do everyday things. The study asked three questions about function:
- Can you turn a key in a lock?
- Can you grip things tightly?
- Can you button your clothes?
Research shows that 80 percent of the patients could do all of these things again after the treatment. They had complete recovery of function. That means they got back to doing normal daily tasks.
No side effects happened
Safety is very important when we talk about any medical treatment. The good news is that no one in this study had any problems. There were no adverse events recorded. An adverse event is the medical term for a bad reaction or side effect.
All patients said they were satisfied with the treatment. That is 100 percent satisfaction.
What made a difference?
The researchers also looked to see if certain things predicted who would do better. They checked if age mattered. They checked if having had previous injections mattered. They checked if the amount of gel mattered.
Surprisingly, none of these things made a difference. People got better regardless of their starting point. This suggests the treatment can help many different people with thumb arthritis.
Common questions
How long does the injection take to work?
The study measured results over six months. The researchers did not report exactly when patients started to feel better. But the pain reduction was measured as an average over the full six months after the injection.
How long does one injection last?
This study followed patients for six months. At that point, patients still had much less pain and better function. The study does not tell us what happens after six months.
Does the injection hurt?
The study does not describe pain during the injection. But it does say there were no adverse events or side effects reported. This suggests the procedure was well tolerated.
Can I get this treatment if I already tried other injections?
Yes. According to this study, 80 percent of the patients had already received two previous treatments with hyaluronic acid injections. They still had good results with this new injection.
About this site: We create simple summaries of medical research about thumb pain and rhizarthrosis. We only use information from published scientific articles. Our goal is to help you understand what doctors and scientists have learned. We do not give medical advice. We just make the science easier to read. Feel free to explore more articles on our site to learn about other treatments and research.
What does this mean for you?
This study suggests that one injection of hyaluronic acid can help with thumb arthritis pain. The results were strong. Pain went down by more than three quarters. Most people could use their hands normally again. No one had problems or side effects.
If you have pain at the base of your thumb, this kind of treatment may be worth talking about with your doctor. The study shows it worked for people with moderate to severe arthritis. It worked even for people who had tried injections before.
Remember, this was a small study with twenty people. It was done at one hospital in Spain. More research with larger groups would help us know even more. But the results are encouraging.
The next step is to talk with your doctor. Ask if this type of injection might be right for you. Bring your questions. Share what you learned here. Together, you can make a plan that fits your situation.
Important information
This article is for educational purposes only. It is not medical advice. It does not replace talking with your doctor. Every person is different. What works for one person may not work for another. Always talk to a healthcare professional before starting any treatment. Only your doctor can evaluate your specific situation and recommend the best care for you.
Scientific source
Study citation: Blasco F, Navarro; Pons J.R, Noguera; D, Acosta-Rubio; Granado M.P, Coronel. International Journal of Advanced Research (2025).
Full article: https://doi.org/10.21474/ijar01/20352
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