Knee osteoarthritis (OA) is a widespread condition that affects millions of people in the UK and around the world. It often causes persistent pain, stiffness, and difficulty moving, making everyday tasks a challenge. Finding effective ways to manage this pain is crucial for maintaining an active, independent lifestyle. Among the many treatment choices available, knee injections have become a popular option to relieve discomfort and improve joint function. In this article, we’ll take a close look at three common knee injection treatments: Arthrosamid, hyaluronic acid injections, and steroid injections. With Arthrosamid being a relatively new option, it’s important for patients to understand how it compares with more established treatments, helping them to make well-informed decisions.

Understanding Knee Injection Options

Knee injection therapy involves delivering medication directly into the knee joint to tackle pain, inflammation, or joint wear and tear. This method is often considered when other treatments—like painkillers, exercise, or physiotherapy—haven’t provided enough relief.

Arthrosamid is a newer injectable treatment based on polyacrylamide hydrogel, a soft gel-like substance. Unlike other gels, Arthrosamid sticks to the lining of the joint (the synovial membrane), creating a supportive scaffold that helps cushion the joint and potentially encourages healing. This sets it apart from typical injections. It’s worth noting that injectable hydrogels like Arthrosamid have been used in medical treatments since the late 1980s, with growing applications in drug delivery and tissue repair (Clegg et al., 2024).

Hyaluronic acid (HA) injections, sometimes called viscosupplementation, have been around for decades. HA is a natural component of the fluid within joints that helps lubricate and cushion them. Injecting HA aims to restore that lubrication, easing movement and reducing pain, especially in early to moderate stages of knee OA.

Steroid injections are another long-established treatment. They work by quickly reducing inflammation inside the joint, offering fairly rapid pain relief. However, their effect tends to be shorter-term than the other options.

Throughout this article, we’ll break down how these treatments work, how effective they are, their safety profiles, and what it means for people with knee OA.

Comparing How They Work, Effectiveness, and How Long Relief Lasts

While all these injections target knee pain, they each do so in different ways.

Arthrosamid acts as a soft yet sturdy build-up inside the joint, supporting the synovial lining and adding volume. This cushioning effect not only eases movement but may also help the joint recover and function better over time. Advances in polymer science and manufacturing techniques over recent decades have made such innovative treatments possible (Clegg et al., 2024).

Hyaluronic acid injections focus on topping up the natural lubricant in the joint fluid. By improving the slickness and shock absorption within the knee, HA helps reduce mechanical friction and pain, although it doesn't aid tissue repair.

Steroid injections work by calming down the inflammation inside the joint, quickly cutting pain and swelling. Pain relief often starts within days, but this effect usually fades after a few weeks to months.

Clinical studies reveal that steroid injections provide the fastest pain relief but for a limited time. Hyaluronic acid may take a few weeks to kick in and often lasts around six months. Arthrosamid’s relief usually develops more slowly but can last for a year or even longer, which some patients find beneficial for managing symptoms in the longer term.

Supporting this, a recent randomised study of knee OA patients showed that Arthrosamid was at least as effective as hyaluronic acid after six months and tended to provide better relief after 12 months. In particular, Arthrosamid was notably more effective in patients under 70 years old, those with a normal body mass index, and those with moderate OA severity (Bliddal et al., 2023).

A systematic review also highlighted that “statistically significant benefits were observed up to 13 months post-injection” with Arthrosamid, and in one trial, the results were better than hyaluronic acid (Cole et al., 2022).

So, while all these treatments have their place, your best choice may depend on how quickly you want relief and how long you hope it will last.

Safety, Who Can Have Them, and How Often

Each injection type has a slightly different safety profile and guidelines for repeat use.

Arthrosamid has shown a strong safety record in trials, with very few lasting side effects. It’s suitable for a wide range of patients with Kellgren–Lawrence grades II to IV knee OA and is often helpful for those who did not respond well to traditional injections. Most patients only need one injection a year, which reduces the number of procedures and clinic visits.

Hyaluronic acid injections are generally safe too, although some people might experience short-term swelling or mild flare-ups in the joint after treatment. These injections are often repeated every six months based on how well they work for each individual.

Steroid injections come with a bit more caution. While effective, they may cause joint infection, cartilage damage if used too frequently, and sometimes an increase in pain shortly after injection. Doctors usually advise limiting steroid injections to three or four times a year.

Finally, access varies: Arthrosamid tends to be offered privately in the UK, while hyaluronic acid and steroids are more widely accessible, including through the NHS.

Cost, Access, and What Patients Say

The price and ease of access to these injections are important considerations.

Arthrosamid, being newer, comes with a higher price tag and is not commonly available on the NHS. For some, the longer relief and fewer injections per year make the cost worthwhile.

Hyaluronic acid injections generally cost less and are more widely available both privately and via the NHS, though local policies can affect accessibility.

Steroid injections are often the cheapest and most accessible option, usually provided free of charge on the NHS.

Patients who have used Arthrosamid often report longer-lasting improvements in pain and joint stability. Others find hyaluronic acid effective with few side effects, while steroid users tend to appreciate the fast relief but sometimes find it doesn’t last long enough.

Ultimately, your decision may depend on budget, how long you want relief, how often you prefer injections, and where you can access treatment.

Questions to Ask Your Doctor

Choosing the right injection is a personal decision that should involve a good conversation with your healthcare provider. Here are some questions to guide your discussion:

• How severe is my osteoarthritis, and which injection would work best for my situation?
• How soon can I expect pain relief, and how long is it likely to last with each option?
• What side effects or risks should I be aware of?
• How frequently can I safely have these injections?
• Are these treatments available through my healthcare system, and what are the costs?

Considering your lifestyle, previous treatments, and preferences will help you make the best choice together.

Wrapping Up

In summary, Arthrosamid, hyaluronic acid, and steroid injections each offer valuable options for managing knee osteoarthritis. Steroids work fast but typically only offer short-term relief. Hyaluronic acid injections provide moderate-duration pain control by replenishing joint fluid. Arthrosamid, with its hydrogel scaffold, may offer longer-lasting support and pain relief. Research shows that it can be especially effective for certain patient groups and appears safe for at least two years post-treatment.

Ultimately, the best injection for your knee pain depends on your individual needs, health status, and treatment goals. With the right information and guidance from your clinician, you can take control of your osteoarthritis management and get back to enjoying the activities you love.

References

Bliddal, H., Beier, J., Hartkopp, A., Conaghan, P. G., & Henriksen, M. (2023). Polyacrylamide hydrogel versus hyaluronic acid in knee osteoarthritis: A subgroup analysis of a randomized study. Orthopaedic Proceedings, 105-B(SUPP_13), 81-81. https://doi.org/10.1302/1358-992x.2023.13.081
Clegg, J. R., Adebowale, K., Zhao, Z., & Mitragotri, S. (2024). Hydrogels in the clinic: An update. Bioengineering & Translational Medicine, 9(6). https://doi.org/10.1002/btm2.10680
Cole, A., Maulana, R. K., Whitehead, J. P., & Lee, P. Y. F. (2022). A systematic review of the novel compound Arthrosamid polyacrylamide (PAAG) hydrogel for treatment of knee osteoarthritis. Medical Research Archives, 10(8). https://doi.org/10.18103/mra.v10i8.2950