Not yet recruitingPhase III/IVObservational

Assessing the efficacy of polyacrylamide hydrogel which is injected into the joints of patients suffering from arthritis in their synovial joints (knee, shoulder etc) instead of steroid injections or joint replacement surgery

Osteoarthritis can cause joint pain, stiffness, and trouble with daily movements. While steroid injections and joint replacement surgery can help, doctors are searching for longer-lasting, less invasive treatments. This clinical trial is testing a gel injection called Arthrosamid (polyacrylamide hydrogel). Adults with ongoing joint pain that has not improved with standard treatments may be able to join. Participants will receive a single injection into their affected joint during a routine hospital visit. Doctors use a local anaesthetic to numb the area and an ultrasound scan to guide the injection safely. After the injection, researchers will follow participants for up to two years. Most follow-up is completed from home using simple questionnaires about joint pain and daily activities, meaning extra hospital trips are usually not needed. The main goal is to find out if this gel safely provides lasting relief without surgery.

At a glance

Status

Not yet recruiting

Phase

Phase III/IV

Sponsor

University Hospital Southampton NHS Foundation Trust

Enrolment target

100

Start

01 Dec 2026

Estimated completion

01 Sep 2028

Osteoarthritis (OA)

What is this study about?

Osteoarthritis is a very common condition in the UK. Over time, the smooth cartilage that cushions the bones in our joints wears down. This often leads to pain, swelling, and stiffness in joints such as the knees, shoulders, or hips, making everyday tasks like walking or climbing stairs difficult.

Doctors usually recommend painkillers, physiotherapy, or steroid injections to help manage symptoms. While steroid injections can give quick relief, their benefits often fade after a few months, and having them too often can weaken the joint tissues. When these options no longer help, major joint replacement surgery is often the next step.

This study looks at a gel injection called Arthrosamid (polyacrylamide hydrogel). The gel stays inside the joint to restore cushioning and help the joint move more smoothly. Researchers hope this single treatment will provide long-lasting pain relief.

By taking part, patients help the NHS find out whether this gel is a safe and effective alternative to surgery or repeated steroid injections. If the results are positive, it could give thousands of people a gentle option to stay active and delay or avoid major operations.

Key takeaways

Tests a long-lasting gel injection (Arthrosamid) to treat joint osteoarthritis.
Aims to provide a simpler alternative to surgery or repeated steroid injections.
Involves just one ultrasound-guided injection given with local anaesthetic.
Follow-up lasts for two years and is mostly done from home via questionnaires.
Led by NHS doctors at University Hospital Southampton.

Who may be eligible?

You may be able to take part if you are 18 or older and have persistent joint pain from osteoarthritis. Your symptoms must not have improved enough with standard treatments, such as pain medicines or exercise, and your doctor must agree that a joint injection is suitable for you.

You will not be able to join if you have an active infection, have had surgery or an injection in that same joint within the past six months, or are planning joint surgery during the study period. It is also not suitable for people with inflammatory conditions like rheumatoid arthritis, serious bleeding disorders, or those who are pregnant or breastfeeding.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

I am aged 18 or over.
I have joint pain from osteoarthritis that standard treatments have not relieved.
I have not had an injection or surgery in this joint in the last 6 months.
I do not have rheumatoid arthritis or an active infection.
I am not pregnant or breastfeeding.

Answer every question to see your result.

What does participation involve?

Taking part involves having a single injection of the study gel directly into your painful joint. The doctor will numb the area with a local anaesthetic and use an ultrasound scan to make sure the gel goes into the exact right spot. After the injection, you can usually go home the same day. Over the next two years, the study team will track your progress. You will not need lots of extra hospital visits; instead, you will fill out questionnaires from home about your pain levels, how easily you can move, and your general wellbeing. The team will also check if you experience any side effects or need any other treatments.

Potential risks and benefits

You may experience lasting pain relief and better joint movement, which could help delay or prevent surgery, though these benefits cannot be guaranteed. The risks are similar to other joint injections and can include temporary soreness, swelling, or bruising around the needle site. Joint infections are very rare. If you decide to take part, you are free to leave the study at any time without giving a reason, and your regular NHS care will not be affected in any way.

Locations (1)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

University Hospital Southampton
City only
Southampton, England

Common questions

What is the gel injection made of?

The gel is called Arthrosamid (polyacrylamide hydrogel). It is a non-dissolving, water-based gel designed to cushion the joint and help it glide smoothly.

Will the injection be painful?

Doctors use a local anaesthetic to numb your joint before the injection, which keeps discomfort to a minimum. You may feel a brief pinch or pressure.

Do I have to keep travelling to the hospital?

No. Aside from the appointment to receive the injection, almost all follow-ups over the two years are completed remotely through simple questionnaires.

Can I still take my normal painkillers?

In most cases, yes. The study team will review your medications and let you know what is safe to take during the trial.

What happens if my joint pain gets worse?

Your safety comes first. If your symptoms do not improve or get worse, your doctor can discuss other treatment options with you at any time.

How to find out more

Niall Hill

niall.hill@nhs.scot +44 1698361100 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.