Introduction

Knee pain and osteoarthritis affect millions worldwide, often making everyday activities a real challenge. Fortunately, modern orthopaedics now offers minimally invasive treatments like Arthrosamid and hyaluronic acid (HA) injections. These therapies aim to relieve joint pain and improve mobility without resorting to surgery. Professor Paul Lee, an expert in cartilage health and Regional Surgical Ambassador, together with the caring team at MSK Doctors, provides specialist treatment in a professional and supportive setting. This guide is designed to help you understand what to expect before, during, and after these injections, so you can make well-informed choices about your knee care.

Understanding Arthrosamid and Hyaluronic Acid Injections

Both Arthrosamid and hyaluronic acid injections are popular options to help ease knee joint pain and improve function. Arthrosamid is a gel-like material that cushions the joint, reducing friction and supporting damaged cartilage. Hyaluronic acid, on the other hand, is a natural substance found in joint fluid that acts like a lubricant, improving smooth joint movement and easing discomfort caused by osteoarthritis. Which treatment is best for you depends on your symptoms and personal health goals. Both involve injecting the substance into the knee joint during a simple outpatient procedure. Arthrosamid generally provides longer-lasting cushioning, while hyaluronic acid works by enhancing lubrication. Many patients find both procedures straightforward and well-supported by clinical teams. A recent review explains that “polyacrylamide (PAAG) hydrogel... adheres to and bulks up the synovial membrane and acts as a scaffold to treat the synovium,” highlighting its innovative approach. Another study adds that this treatment “provides positive results for at least 2 years,” reflecting promising long-term benefits.

What Happens During the Injection?

The injection process for both Arthrosamid and hyaluronic acid is designed to be precise, safe, and as comfortable as possible. Ultrasound imaging helps the doctor find the exact spot inside your knee joint to deliver the treatment accurately. The procedure itself takes just a few minutes. A fine needle is used to inject the substance under sterile conditions. You might feel a quick pinch or some pressure, but a local anaesthetic can be applied beforehand to ease any discomfort. Afterwards, you can usually go home on the same day. It’s important to know that “injections were given by an investigator experienced in administering intra-articular injections,” showing the treatment is carried out by skilled professionals. Throughout the process, Professor Lee and the MSK Doctors team will answer your questions and keep you comfortable and informed.

Immediate Aftercare and Recovery Timeline

After your injection, take it easy and rest your knee for the rest of the day. You might notice some mild swelling or tenderness around the injection site—this is normal and should settle quickly. Applying ice packs and using over-the-counter painkillers can help with any discomfort. How quickly you recover depends on the type of injection. Some patients experience relief within days after a hyaluronic acid injection, thanks to its lubricating effect. Arthrosamid may take a little longer to work but often provides longer-lasting support. Mild soreness or swelling is common after treatment and usually lasts less than a week. One study reported that patients started with a pain score median of 7 out of 10, which dropped to 3 within 3 months across all treatments. Interestingly, “by 12 months, pain scores returned to baseline in hyaluronic acid and steroid groups, while those receiving Arthrosamid (iPAAG) remained slightly improved.” This suggests longer-lasting benefits for Arthrosamid in some patients. For at least one to two weeks after your injection, avoid high-impact activities like running or heavy lifting. If you notice worsening pain, redness, or fever, contact MSK Doctors promptly. The team is always on hand to support you through your recovery.

Frequently Asked Questions: Practical Concerns and Expectations

When can I get back to daily activities?
Most people can resume light activities the next day, but it's best to avoid strenuous or high-impact exercise for about one to two weeks.

Is pain normal after the injection?
Some mild aching or tenderness is common and should ease within a few days. If pain worsens or feels severe, get in touch with your healthcare provider.

Are there things I should avoid?
Yes, avoid running, jumping, or lifting heavy weights in the early recovery phase to protect your knee.

What about side effects?
Most patients experience only minor swelling or discomfort at the injection site. Serious side effects are very rare. One study found that Arthrosamid had “the highest patient acceptable symptom state rates (72%, 54%, and 42% at 3, 6, and 12 months),” supporting its safety and effectiveness.

When should I seek medical advice?
Contact your clinic if you have increasing pain, redness, swelling, warmth around the knee, or a fever.

Always speak to your healthcare team if you’re unsure about any symptoms or concerns.

Conclusion

Arthrosamid and hyaluronic acid injections offer valuable, minimally invasive ways to manage knee osteoarthritis pain and improve joint function. Knowing what to expect throughout the process can help you feel confident and empowered in your care. With the expert guidance of Professor Paul Lee and the MSK Doctors team, you’ll receive tailored, compassionate treatment every step of the way. For personalised advice, always consult a qualified healthcare professional.

References

• 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
• 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
• 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