If you have thumb pain from arthritis, you know how hard it can be to open a jar, turn a key, or hold a pen. You may have tried medicines and splints but still feel stuck. This article looks at a study that tested a special injection for thumb arthritis. The injection used a substance called hyaluronic acid. We will explain what happened in the study and what the results mean for you.
Key Findings at a Glance
- Research shows that a single injection of hyaluronic acid reduced thumb pain by 42% after three months.
- Pain levels dropped from an average of 6.5 out of 10 to 3.9 out of 10.
- Studies indicate that this treatment worked for people with mild arthritis and also for those with advanced arthritis.
- More than one out of every two patients used less pain medicine after the injection.
- Side effects were mild and temporary, lasting only one to seven days.
Here are the three main things you will learn:
- What this treatment is and how it was tested
- How much pain relief patients felt after three months
- Whether the treatment works for everyone, no matter how bad the arthritis is
In This Article
What Is Thumb Arthritis and Why Does It Hurt So Much?
Thumb arthritis is also called rhizarthrosis. Doctors sometimes call it trapeziometacarpal osteoarthritis. That is a long name for the wearing away of the cartilage in the joint at the base of your thumb.
This joint is one of the busiest in your hand. You use it every time you pinch, grip, or twist something. When the cartilage wears away, everyday tasks become painful. Many people try pain medicines and special splints for the thumb. Sometimes these help a little. Sometimes they do not help enough.
You may be wondering why this matters. That brings us to what doctors are looking for: better ways to ease the pain without surgery.
What Did the Study Test?
According to this study, researchers tested a special gel that gets injected into the thumb joint. This gel is made of hyaluronic acid combined with a substance called mannitol. Hyaluronic acid is a natural substance already found in your joints. It acts like a cushion and lubricant. The gel used in this study was modified with mannitol and cross-linked. That means the molecules are connected in a special way to make the gel last longer in the joint.
The doctors injected between 0.6 and 1 milliliter of this gel into the thumb joint. They used imaging guidance. That means they used special pictures like ultrasound or X-rays to make sure the needle went into the right spot. Each patient got only one injection. Then the doctors watched what happened over the next three months.
Who Was in the Study?
Research shows that 122 patients joined this study. Most of them were women. In fact, 76 out of every 100 patients were women. The average age was 60 years old. The patients had been living with thumb pain for an average of 36 months. That is three years of discomfort.
Let us look closer. All these patients had already tried other treatments. They had used pain medicines or thumb splints or both. But those treatments did not give them enough relief. So they agreed to try this injection.
Doctors took X-rays of each patient’s thumb. They used a special way of grading the arthritis called the Dell grade. The scale goes from 1 to 4. Grade 1 is mild arthritis. Grade 4 is very advanced arthritis. Here is how the patients were spread out:
| Dell Grade | Severity | Percentage of Patients |
|---|---|---|
| 1 | Mild | 23% |
| 2 | Moderate | 36.8% |
| 3 | Advanced | 36.8% |
| 4 | Very Advanced | 3.5% |
Almost all patients finished the study. Only 2 patients out of 122 did not complete the three month follow up. That is a very high completion rate.
What Did the Results Show?
Here is where it gets interesting. The doctors asked patients to rate their pain on a scale from 0 to 10. Zero means no pain. Ten means the worst pain you can imagine. Before the injection, the average pain was 6.5 out of 10. That is a lot of pain. After three months, the average pain dropped to 3.9 out of 10.
Let us break that down. The pain went down by 2.7 points. That is a 42% reduction in pain. In other words, patients felt almost half as much pain after the injection.
Studies indicate that more than one out of every two patients also used less pain medicine after the treatment. That is important. It means the injection did not just move the problem somewhere else. It actually helped people feel better and need fewer pills.
Were There Any Side Effects?
According to medical evidence, any treatment can have side effects. This study found that 11 out of every 100 patients had some side effects. All of these were mild. Patients felt more pain during the injection or right after it. This extra pain did not last long. It went away on its own within one to seven days. No one needed extra treatment for the side effects. No serious problems happened.
This is good news. It means the treatment is safe for most people. The temporary pain was uncomfortable but not dangerous.
Does It Matter How Severe Your Arthritis Is?
You may be wondering if this treatment only works for people with mild arthritis. The answer is no. Research shows that patients with advanced arthritis benefited just as much as those with mild or moderate arthritis. At the start, all the Dell grade groups had about the same level of pain. After three months, all groups felt better. There was no big difference between them.
One small note: patients with grade 2 arthritis seemed to have slightly fewer people who responded well. But this difference was not large enough to be certain. The researchers could not find any clear reason why some people responded better than others. Age, gender, and severity of arthritis did not predict who would feel the most relief.
This is encouraging. It suggests that even if your arthritis is advanced, this treatment might still help you.
What About People Who Did Not Get Relief?
Not everyone felt better. Some patients still had pain after three months. The study did not find a way to predict who would respond and who would not. More research is needed to understand why some people benefit more than others.
About This Site
This site is here to help you understand the science behind thumb pain and rhizarthrosis. We read published medical studies and explain them in simple language. We never make up information. Everything we share comes from real scientific articles. If you found this helpful, explore more content on our site. You will find clear answers to your questions about thumb arthritis treatments, prevention, and daily living tips.
Frequently Asked Questions
How long does the injection take to work?
According to this study, doctors measured pain relief at three months after the injection. Some patients may feel relief sooner, but the study tracked results at the three month mark. The benefit lasted at least that long.
Will I need more than one injection?
This study tested only one injection. Patients received a single dose and were followed for three months. The research did not look at whether repeat injections would help even more. That is a question for future studies.
Is this injection safe for me?
Research shows that the injection was safe in this study. The only side effects were temporary increases in pain that went away within a week. However, every person is different. Always talk to your doctor about your own health before trying any new treatment.
Can I stop taking my pain medicine after the injection?
Studies indicate that more than half the patients in this study used less pain medicine after the injection. But you should never stop your medicine without talking to your doctor first. Your doctor can help you decide the best plan for you.
What Does This Mean for You?
If you have thumb arthritis that is not getting better with medicine or splints, this study offers hope. A single injection of hyaluronic acid combined with mannitol helped many patients feel less pain. The treatment worked for people with mild arthritis and also for those with advanced arthritis. Side effects were mild and short lived.
This does not mean the injection is right for everyone. But it is worth talking to your doctor about. Ask if this treatment might help you. Bring this article with you if it helps you explain what you have learned.
Remember, you do not have to live with constant thumb pain. There are options. Keep asking questions. Keep looking for answers. You deserve to feel better.
Disclaimer
This article is for informational purposes only. It is not medical advice. It does not replace a conversation with your doctor. Always talk to a healthcare professional before starting any new treatment. Every person is different. What works for one person may not work for another. Your doctor knows your health history and can guide you to the best choice for you.
Study Reference
This article is based on the following published research:
Dauvissat, J., Rizzo, C., Lellouche, H., Porterie, J., Melac-Ducamp, S., Locquet, V., Travers, V., Maillet, B., & Conrozier, T. (2018). Safety and Predictive Factors of Short-Term Efficacy of a Single Injection of Mannitol-Modified Cross-Linked Hyaluronic Acid in Patients with Trapeziometacarpal Osteoarthritis. Results of a Multicentre Prospective Open-Label Pilot Study (INSTINCT Trial). Clinical Medicine Insights: Arthritis and Musculoskeletal Disorders.
https://doi.org/10.1177/1179544118782901
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