Arthrosamid® Knee Injections in Central London

✔ Ultrasound-guided precision

✔ Central London clinics

✔ Established long term non-surgical strategy for knee osteoarthritis

✔ Consultation & suitability assessment included

What Is Arthrosamid®?

Arthrosamid® is a long-acting polyacrylamide hydrogel injection used to help manage pain and stiffness caused by knee osteoarthritis. It is designed for people seeking a non-surgical option when symptoms persist despite exercise, physiotherapy, or previous injections.

Unlike steroid or hyaluronic acid injections, Arthrosamid is not rapidly broken down by the body.

Once injected into your knee joint, the hydrogel integrates with the synovial lining (joint capsule), forming a durable cushioning matrix designed to:

• Improve shock absorption

• Reduce mechanical stress on joint surfaces

• Support smoother joint movement

Arthrosamid does not regenerate cartilage or reverse arthritis — it aims to modify the joint environment to improve comfort and function.

Clinical studies show sustained improvements in pain and function in appropriately selected patients.

How Arthrosamid Works Inside the Knee Joint

Arthrosamid is made from a biocompatible polyacrylamide hydrogel.

After injection, the gel integrates with the synovial tissue lining your knee joint rather than acting as a temporary lubricant. Over time, it forms a stable, cushioning matrix within the joint.

Because Arthrosamid is not biodegradable, it remains in place and continues to provide mechanical support, which is why symptom relief can last significantly longer than with steroid or hyaluronic acid injections.

This longer-acting effect makes Arthrosamid an option for people who have found that traditional injections wear off too quickly.

The Science Behind Arthrosamid

Arthrosamid® is composed of approximately 97.5% water and 2.5% cross-linked polyacrylamide hydrogel — a material designed to be stable, non-degradable, and biocompatible within the knee joint environment.

Once injected, Arthrosamid does not behave like a short-term lubricant. Instead, it integrates with the synovial lining and forms a durable cushioning matrix within the joint. This helps absorb mechanical forces and reduce friction during movement.

Because Arthrosamid is not rapidly broken down or absorbed by the body, its mechanism is fundamentally different from:

• Steroid injections, which act by temporarily reducing inflammation

• Hyaluronic acid injections, which are gradually degraded over time

From a biomechanical perspective, the hydrogel helps to:

• Improve shock absorption within the knee

• Reduce stress on irritated joint surfaces

• Support smoother joint movement during everyday activities

Arthrosamid does not cure osteoarthritis or regenerate cartilage. It is designed to modify the joint environment to help reduce pain and stiffness and improve comfort, particularly in people with mild to moderate osteoarthritis.

Clinical studies have demonstrated sustained improvements in pain and function in appropriately selected patients. Individual results vary, and early research suggests outcomes may be better in more active people with moderate osteoarthritis.

Antibiotics Before Your Arthrosamid Injection

Because Arthrosamid is a long-acting hydrogel that remains within the joint, a single precautionary dose of antibiotics is prescribed before treatment to reduce the already low risk of infection.

Following a safety and allergy check, I will arrange a prescription to be sent to your local pharmacy, which you can collect prior to your injection appointment.

How to Take the Antibiotics

• Take the antibiotics once, 1–2 hours before your injection

• There are no special requirements

• The antibiotics do not need to be taken with food

This forms part of the standard Arthrosamid safety protocol alongside:

• Full aseptic preparation

• Ultrasound-guided needle placement

• Structured injection technique

The official Arthrosamid antibiotic protocol can be downloaded here:

https://arthrosamid.ams3.cdn.digitaloceanspaces.com/new-uploads/downloads/Statement-on-the-use-of-prophylactic-antibotics-with-Arthrosamid-injections.pdf

What Happens on the Day?

Your appointment is designed to be straightforward, unhurried, and clinically thorough.

On arrival, together we will review your symptoms, medical history, and any previous imaging. I will then perform a diagnostic ultrasound scan of your knee to assess the joint and confirm suitability before proceeding.

If appropriate, your Arthrosamid® injection is carried out during the same visit.

Your appointment typically includes:

1️⃣ Together we review your symptoms and ultrasound findings

2️⃣ Skin preparation using full aseptic technique

3️⃣ Local anaesthetic under ultrasound guidance to improve comfort

4️⃣ Arthrosamid injection delivered directly into your knee joint under real-time ultrasound

5️⃣ Visual confirmation that the hydrogel has been accurately placed

6️⃣ Aftercare advice and guidance on activity over the following weeks

The procedure itself usually takes around 30–40 minutes.

You’ll be able to walk out the same day.

Ultrasound images (and where appropriate video recordings) are captured during your injection and are available to you afterwards, providing reassurance that the Arthrosamid has been placed correctly inside your joint.

Before you leave, together we will go through clear post-procedure guidance and what to expect during recovery.

Arthrosamid Frequently Asked Questions

How long does Arthrosamid last?

Arthrosamid is non-biodegradable and designed to integrate with the lining of your knee joint. Clinical studies show sustained improvements in pain and function, with symptom relief lasting several years in some patients — including reports of benefit for up to 5 years.

Individual results vary.

Is Arthrosamid better than steroid injections?

They work differently.

Steroid injections aim to reduce inflammation temporarily and often provide short-term relief.

Arthrosamid is designed to modify the joint environment itself, offering a longer-lasting alternative for people whose symptoms return quickly after steroids or hyaluronic acid injections.

Does the injection hurt?

Local anaesthetic is used. Most people describe pressure or discomfort rather than pain. The ultrasound guidance also helps minimise unnecessary tissue irritation.

How much does Arthrosamid cost?

The total cost is £2299, which includes:

• Clinical assessment

• Ultrasound guidance

• Arthrosamid product (six vials)

• Injection procedure

• Aftercare guidance

There are no hidden extras.

Am I suitable?

Suitability depends on:

• The stage of your knee osteoarthritis

• Your symptoms

• Previous treatments

• Clinical assessment and ultrasound findings

You’ll be assessed before proceeding to ensure this is appropriate for you.

Is this available on the NHS?

No — Arthrosamid is currently a private treatment.

If you’d like to explore whether Arthrosamid is appropriate for your knee osteoarthritis, you can book a consultation below.

This includes clinical assessment and ultrasound evaluation to confirm suitability.

Post Arthrosamid Injection Guidance

• Rest and avoid strenuous activity for the first 24–72 hours after the injection.

• Gradual return to normal daily activities over the first 2 weeks.

• Please message me 2 weeks following your Arthrosamid injection.

Following this period of rest and following checking in with me, it is recommended to start a more structured exercise program. 

Many patients will have already undergone a structured exercise program with appropriate rehabilitation supervision and should get back to these programs. 

For other patients, a basic program which should help when done in a pragmatic manner can be found below. 

Research Publications Concerning Arthrosamid Injections

Effectiveness and safety of polyacrylamide hydrogel injection for knee osteoarthritis: results from a 12-month follow up of an open-label study | Journal of Orthopaedic Surgery and Research 

https://doi.org/10.1186/s13018-024-04756-2

This open-label clinical study assessed the effectiveness and safety of a single intra-articular injection of polyacrylamide hydrogel in patients with knee osteoarthritis over 12 months. The results showed sustained and clinically meaningful improvements in pain, stiffness, and physical function throughout the follow-up period, with a majority of patients meeting established responder criteria. The treatment was generally well tolerated, with no major safety concerns identified, supporting polyacrylamide hydrogel as a potentially durable symptomatic treatment option for knee osteoarthritis.

Polyacrylamide gel versus hyaluronic acid for the treatment of knee osteoarthritis: a randomised controlled study 

https://doi.org/10.1097/MD.0000000000044655

In this retrospective cohort analysis published in Medicine, researchers examined medical records of people with knee osteoarthritis who received a single intra-articular injection of polyacrylamide hydrogel, hyaluronic acid, or corticosteroids. All three treatments resulted in improvements in pain and function in the short term, but polyacrylamide hydrogel tended to provide more sustained relief than corticosteroids and showed similar effectiveness to hyaluronic acid at follow-up. While differences between groups diminished over longer follow-up, patient-reported outcomes such as meaningful improvement and acceptable symptom state were generally more favorable with polyacrylamide hydrogel, suggesting it may offer a viable alternative to traditional viscosupplementation and steroid injections for symptom management in knee osteoarthritis.

A Systematic Review of the Novel Compound Arthrosamid Polyacrylamide (PAAG) Hydrogel for Treatment of Knee Osteoarthritis | Medical Research Archives 

https://doi.org/10.18103/mra.v10i8.2950

This systematic review looked at all available clinical evidence on polyacrylamide (PAAG) hydrogel injections — including Arthrosamid — for knee osteoarthritis by searching major medical databases up to April 2022. Across multiple studies involving a total of 463 patients, the review found that intra-articular PAAG hydrogel injections were generally safe and associated with statistically significant improvements in pain and function at 12 months and longer follow-up in several cohorts. In a randomized trial included in the review, PAAG hydrogel showed numerically better outcomes than hyaluronic acid, and some longer-term data suggested symptom relief could persist for up to two years. Adverse events were generally mild, and no serious long-lasting safety issues were reported, supporting the conclusion that PAAG hydrogel is a promising treatment option for knee osteoarthritis with sustained benefit and a favorable safety profile at least up to two years post-injection.