Introduction

Knee osteoarthritis affects millions, causing pain, stiffness, and difficulty moving around. While surgery is an option for some, many seek non-surgical treatments that ease symptoms and improve day-to-day life. Knee injections are a popular choice, offering targeted relief. In this guide, we’ll compare Arthrosamid—a newer type of injectable—with traditional options like corticosteroids, hyaluronic acid, and platelet-rich plasma (PRP). Our aim is to give you clear, research-backed insights so you can understand the differences and discuss options with your healthcare provider confidently.

What Are the Different Knee Injection Treatments?

Here’s a quick look at the main injection treatments used for knee osteoarthritis: Arthrosamid (Polyacrylamide Hydrogel)

• A long-lasting gel that stays inside the joint, supporting the soft tissues by thickening the synovial membrane.
• Given as a single 6 mL injection.
• Suitable for moderate to severe cases, it aims for durable symptom relief.
• Recent studies suggest it “may be a complementary option in individualised osteoarthritis management,” making it a promising choice for some patients.

Corticosteroid Injections

• These reduce inflammation quickly by calming down the immune response.
• Usually delivered as a single injection but can be repeated if needed.
• Best for short-term relief during flare-ups.

Hyaluronic Acid (HA) Injections

• A natural lubricant that helps the knee glide more smoothly.
• Typically given as several smaller injections over a few weeks.
• Mostly used in mild to moderate osteoarthritis to ease pain and improve function.

Platelet-Rich Plasma (PRP)

• Made from your own blood, it’s rich in growth factors that may encourage tissue repair.
• Usually requires multiple injections.
• An emerging treatment, especially for early-stage osteoarthritis, but protocols vary widely.

How Do These Treatments Compare in Effectiveness, Duration, and Safety?

Understanding how these injections perform over time and how safe they are is vital when choosing your treatment. Effectiveness and Duration
Arthrosamid has been shown to provide significant pain relief lasting up to two years or more after just one injection. Some recent research even shows benefits lasting three years. This is because the gel physically supports joint tissues. One study found “clinically relevant and statistically significant decreases” in pain and stiffness lasting three years. When compared to other injections, one study reports that “iPAAG offers comparable short-term efficacy and modest advantage at 6 months. However, long-term superiority is limited.” It “outperformed corticosteroids at 6 months” but was similar to hyaluronic acid. At 12 months, symptom scores for hyaluronic acid and corticosteroids tended to return to baseline, while Arthrosamid remained stable. This suggests Arthrosamid may maintain its benefits longer, though differences aren’t always statistically significant beyond a year. Corticosteroids work quickly but usually only for a few months. Hyaluronic acid typically helps for around six months, making daily movement easier during that time. PRP shows promise but needs more long-term evidence to be widely recommended. Safety
Arthrosamid is well tolerated with few side effects and no serious long-term risks reported in studies. Corticosteroids are generally safe but can carry risks if used repeatedly, including possible damage to cartilage. Hyaluronic acid injections may cause minor injection site irritation but are otherwise safe. PRP’s primary advantage is its natural origin, which limits immune reactions, although preparation methods differ across clinics. Summary of Pros and Cons

• Arthrosamid
• • Pros: Long-lasting relief with just one injection; may delay surgery.
  • Cons: Long-term superiority over other treatments isn’t yet certain; cost may be higher.
• Corticosteroids
• • Pros: Fast pain relief; widely available and affordable.
  • Cons: Effects are short-lived; risks with frequent use.
• Hyaluronic Acid
• • Pros: Good joint lubrication; moderate pain relief duration.
  • Cons: Requires several injections; benefits may vary.
• PRP
• • Pros: Uses your own blood; potential for tissue repair.
  • Cons: Protocols differ; less long-term research.

What About Cost, Availability and Who Are They For?

Besides effectiveness, cost, access, and patient suitability play big roles in deciding treatment. Cost and Access
In the UK, Arthrosamid is usually only available privately and tends to cost more. Corticosteroid and hyaluronic acid injections are often provided via the NHS and generally less costly. PRP treatments are mostly private and can be pricey due to customised preparation. Who Should Consider Which?

• Arthrosamid is ideal for those with moderate to severe osteoarthritis who want longer-lasting relief and perhaps to postpone surgery.
• Corticosteroids suit those needing quick relief during painful flare-ups.
• Hyaluronic acid injections help those with mild to moderate disease looking for joint lubrication and symptom improvement.
• PRP might interest younger patients or those with early osteoarthritis looking into regenerative options.

If standard treatments haven’t worked well or you seek longer intervals between injections, Arthrosamid may be a good option. Otherwise, corticosteroids or hyaluronic acid could be preferable for faster or earlier-stage relief.

What Do Experts Recommend?

Choosing the right knee injection isn’t one-size-fits-all. Experts advise working closely with healthcare professionals to weigh factors like disease severity, personal preferences, prior treatments, costs, and overall health. Arthrosamid is a notable advancement offering lasting symptom control, but traditional injections still have important roles. With osteoarthritis varying widely between individuals, personalised treatment is key. Talk openly with your clinician about the options and what fits best with your lifestyle and needs. This guide aims to give you a clear and balanced understanding of knee injection treatments, helping you make informed choices and have productive discussions with your healthcare team.

References

• 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
• Bliddal, H., Beier, J., Hartkopp, A., Conaghan, P. G., & Henriksen, M. (2023). Polyacrylamide hydrogel for the treatment of knee osteoarthritis: 3 year follow up results of a prospective clinical study. Annals of the Rheumatic Diseases. https://doi.org/10.1136/annrheumdis-2023-eular.6038
• Aykaç, B., Dinç, M., Nar, Ö. O., Karasu, R., & Bayrak, H. Ç. (2025). Comparative efficacy of polyacrylamide hydrogel versus hyaluronic acid and corticosteroids in knee osteoarthritis: A retrospective cohort study. Medicine, 104(38), e44655. https://doi.org/10.1097/md.0000000000044655