If your thumb hurts when you open a jar or turn a key, you might have rhizarthrosis. This is a big word for arthritis at the base of your thumb. Many people get injections to help with the pain. But how many injections do you need?
Scientists studied this question. They wanted to know if one shot works as well as three shots. They used a special medicine called hyaluronic acid. This medicine helps cushion your joints like oil in a squeaky door.
Here is what they found out.
Key Findings at a Glance
- One injection of hyaluronic acid reduced thumb pain for up to three months.
- Three injections reduced pain and improved how well the thumb worked for six months.
- Both treatments showed no big difference in pain relief when compared directly.
- Doctors used ultrasound to guide the needle into the right spot in the thumb joint.
- If you want lasting functional improvement, three injections may be better than one.
What is rhizarthrosis?
Many people get this kind of arthritis as they get older. Your thumb might feel stiff in the morning. It might hurt when you pinch something. Sometimes the base of your thumb looks swollen or feels tender.
Doctors try different ways to help. They might suggest rest, splints, or exercises. Sometimes medicine works best when it goes right into the joint. That is where hyaluronic acid comes in.
What did the study do?
According to this study, doctors treated 40 patients with thumb arthritis. They split them into two groups. Each group had 20 people.
Group A got one injection of hyaluronic acid. This is a gel like substance that your body makes naturally. It helps joints move smoothly. The doctors used ultrasound to guide the needle. Ultrasound is like a camera that uses sound waves to see inside your body. This makes sure the medicine goes exactly where it needs to go.
Group B got three injections. They got one shot each week for three weeks. Each shot had the same amount of medicine as the single shot in Group A.
Here is where it gets interesting.
The doctors checked on everyone at different times. They looked at how people felt after one month, three months, and six months. They asked about pain. They tested how well the thumb moved. They asked if people could do everyday tasks like work and household chores.
How did doctors measure the results?
Research shows that doctors used four different tests:
- VAS (Visual Analogue Scale): This is a simple pain scale. You point to a line to show how much your thumb hurts. Zero means no pain. Ten means the worst pain you can imagine.
- Kapandji Thumb Opposition Test: This checks if you can touch your thumb to different parts of your hand. It shows how well your thumb moves.
- DASH Score: This is a questionnaire about daily activities. It asks if you can open jars, turn doorknobs, or write without pain.
- DASH Work: This part asks if your thumb problem affects your job.
What happened with one injection?
Patients who got one injection felt better. Their pain went down. This improvement lasted for three months. The doctors saw a statistically significant change. This means the difference was real and not just by chance.
Let us look closer.
After one month, people reported less pain compared to before the injection. After three months, their pain was still lower. But after six months, the pain reduction was not as strong.
Their thumb movement got a little better too. But this only showed up clearly at the six month check. The test for touching different parts of the hand improved compared to before treatment.
The one injection group did not show big improvements in their ability to do daily tasks or work. The DASH scores did not change much.
What happened with three injections?
According to this study, patients who got three injections had more improvements. Their pain went down. Their thumb worked better. They could do more tasks without trouble.
These improvements showed up at every check. After one month, three months, and six months, people felt better than before treatment. The differences were statistically significant.
You may be wondering why this matters.
The three injection group improved in all four tests. Their pain scores went down. Their thumb movement got better. Their daily activity scores improved. Even their work ability scores went up.
This means they not only felt less pain but could also use their thumbs better in real life.
Which treatment is better?
Here is the surprising part. When doctors compared the two groups directly, they did not find a big difference in pain levels. Both groups had less pain than before. The difference between one shot and three shots was not statistically significant.
But the three injection group showed improvements in more areas. They had better function. They could do more with their thumbs.
The study suggests this: If you want short term pain relief, one injection may be enough. If you want your thumb to work better for longer, three injections may be the better choice.
| Treatment | Pain Relief | Thumb Function | How Long It Lasted |
|---|---|---|---|
| One injection | Yes, up to 3 months | Small improvement at 6 months | Up to 3 months for pain |
| Three injections | Yes, up to 6 months | Clear improvement in movement and daily tasks | Up to 6 months for pain and function |
Why does hyaluronic acid help?
Hyaluronic acid is a substance your joints make naturally. It acts like a cushion and a lubricant. When you have arthritis, your body does not make enough of it. The joint gets dry and stiff.
When doctors inject hyaluronic acid, they add that cushion back. This helps the bones glide more smoothly. It reduces friction. It may also help reduce swelling inside the joint.
The doctors in this study used low molecular weight hyaluronic acid. This means the molecules are smaller. Some doctors think smaller molecules spread more easily through the joint.
About this site
We simplify medical science for people with thumb pain and rhizarthrosis. We read published scientific articles so you do not have to. We explain the findings in simple words. Every post is based on real research from medical journals. If you found this helpful, explore more content on our site. You are not alone in dealing with thumb arthritis. Knowledge helps you make better choices.
Frequently asked questions
Does the injection hurt?
The study does not describe pain during the injection. Most patients report feeling a pinch or pressure. Doctors often use ultrasound to guide the needle. This helps them place it correctly and may make the process gentler. Some doctors numb the skin first.
How long does each treatment take?
The study does not say how long each injection takes. Most joint injections take just a few minutes. The ultrasound guidance adds a little time. You may need to rest your thumb for a day or two afterward.
Can I use my thumb right after the injection?
The study does not give specific instructions about activity after injection. Many doctors suggest resting your thumb for a day or two. Then you can slowly return to normal activities. Always follow your own doctor’s advice.
Is three injections three times more expensive than one?
The study does not discuss cost. Three injections do mean three visits and three doses of medicine. This could cost more. But if it helps you feel better for longer, it may be worth it. Talk to your doctor about what makes sense for you.
What does this mean for you?
Research shows that hyaluronic acid injections can help with thumb arthritis pain. Both one injection and three injections made people feel better.
If you want quick pain relief, one injection may be enough. It can reduce pain for up to three months. If you want your thumb to move better and do more tasks, three injections may help more. The benefits can last up to six months.
The choice depends on what you need most. Talk with your doctor. Explain your goals. Do you mostly need pain relief? Or do you need to use your thumb better at work or home?
Every person is different. What works for one person may not work the same for another. This study gives you information to help guide your conversation with your doctor.
You deserve to have a thumb that works without pain. These injections are one tool that may help you get there.
Important disclaimer
This article is for educational purposes only. It is not medical advice. It does not replace a visit to your doctor. Every person’s health situation is unique. Only your doctor knows your full medical history. Always talk to a healthcare professional before starting any new treatment. If your thumb pain is severe or getting worse, see a doctor soon.
Study source
This article is based on research published by Perugia, D., Lanzetti, R. M., Vetrano, M., Vavala, C., Pascali, S., Nusca, S. M., Santoboni, F., and Vulpiani, M. C. in Muscle Ligaments and Tendons Journal in 2020.