An evidence-based guide to Arthrosamid knee injections, treatment costs, clinical effectiveness and safety.

Arthrosamid is an increasingly recognised injectable treatment for knee osteoarthritis, offering the potential for long-lasting improvements in knee pain, stiffness and mobility.

However, with private treatment costing on average £2800 in the UK (up to £3300), patients understandably want to know whether the clinical evidence justifies the investment.

At Pro Sports Medicine, we examine how Arthrosamid works, its effectiveness, potential risks and whether it represents good value compared with other knee osteoarthritis treatments.

What Is Arthrosamid and How Does It Work?

Arthrosamid is a non-biodegradable hydrogel injection consisting of 97.5% water and 2.5% cross-linked polyacrylamide.

Unlike corticosteroid or hyaluronic acid injections, Arthrosamid integrates into the synovial tissue lining the knee joint, creating a cushioning effect intended to reduce pain and improve function.

It is not fast acting… Its principal advantage is the potential for sustained longer term symptom relief following a single injection.

Importantly, Arthrosamid does not regenerate cartilage or cure osteoarthritis. It is designed to manage symptoms and improve quality of life.

How Much Does Arthrosamid Cost in the UK?

Private Arthrosamid treatment in the UK commonly costs between £2,300 and £3,300 per knee, depending on the clinic and treatment package.

Arthrosamid Price at Pro Sports Medicine, Cardiff

£2,500 per knee

Our clinical pathway includes assessment of treatment suitability, review of relevant imaging, specialist medical authorisation, pre-procedure safety checks, ultrasound-guided injection and appropriate aftercare.

The £2,500 treatment fee should be distinguished from the wider clinical pathway. Any separately charged consultations, investigations, prescriptions or rehabilitation appointments will be explained before treatment.

Arthrosamid’s higher price reflects the specialist hydrogel implant, clinical expertise and procedural requirements, as well as its potential for longer-lasting effects.

Learn more about Arthrosamid treatment at Pro Sports Medicine

Does Arthrosamid Work? What Does the Research Show?

The clinical evidence supporting Arthrosamid continues to develop, with randomised controlled trials and prospective studies reporting improvements in knee osteoarthritis symptoms.

Five-Year Clinical Results

Two published follow-up studies have reported sustained improvements in knee pain, stiffness and physical function for up to five years following a single Arthrosamid injection.

A 2025 study by Bliddal and colleagues reported improvements in patient-reported outcomes at five years, with 27 participants completing the follow-up.

A further study published in 2026 also reported sustained improvements at five years, with 58 participants completing follow-up.

These findings are encouraging, particularly for patients seeking longer-term symptom management.

However, both long-term extensions had limitations, including participant attrition and the absence of a continuing randomised comparison group.

The evidence suggests Arthrosamid may provide several years of symptom relief for some patients, but five years of benefit cannot be guaranteed.

Research comparing Arthrosamid with hyaluronic acid has also demonstrated improvements in symptoms, although consistent superiority over alternative injections has not been established.

How Safe Is Arthrosamid?

Published studies suggest a generally reassuring safety profile, although risks remain.

Potential side effects include:

• Temporary knee pain, swelling or stiffness

• Local inflammatory reactions

• Baker’s cyst symptoms

• Infection, including septic arthritis

• Failure to achieve meaningful symptom improvement

As Arthrosamid is a permanent, non-degradable implant, its long-term implications should be considered carefully.

The manufacturer requires antibiotic prophylaxis before treatment to reduce infection risk.

Five-year follow-up studies have not identified a clear new device-related safety signal among participants assessed, but larger independent studies are needed to establish rare and very long-term risks.

Patients with active infection, certain pre-existing implants or other contraindications may be unsuitable. Individual medical assessment is essential.

Is Arthrosamid Worth £2,500?

The value of Arthrosamid depends on the magnitude and duration of symptom improvement.

For patients who experience meaningful pain reduction and improved mobility over several years, a single £2,500 treatment may represent worthwhile expenditure.

However, the treatment is less cost-effective when improvement is limited or short-lived.

Compared with corticosteroid, hyaluronic acid and PRP injections, Arthrosamid offers a different mechanism and the potential for sustained benefit without planned repeat injection courses.

Nevertheless, there is currently insufficient high-quality evidence to conclude that Arthrosamid is consistently superior or more cost-effective than other treatments.

The decision should depend on clinical suitability and realistic expectations, not simply the potential duration of relief.

Who Is Suitable for Arthrosamid?

Arthrosamid may be considered for adults with symptomatic knee osteoarthritis who have not achieved sufficient improvement through conservative treatments.

Potential candidates include patients who:

• Experience persistent knee pain, stiffness or reduced mobility.

• Have confirmed knee osteoarthritis.

• Have undergone appropriate physiotherapy or other conservative management.

• Wish to consider non-surgical treatment options.

• Understand the potential benefits, limitations and risks.

Suitability depends on symptoms, examination, imaging, medical history and previous treatment response.

Patients with advanced osteoarthritis require particularly careful assessment, especially when knee replacement may offer a more appropriate long-term solution.

Frequently Asked Questions

How long does Arthrosamid last?

Arthrosamid is not fast acting… Published clinical studies have reported improvements lasting up to five years in some patients. However, individual responses vary, and sustained relief cannot be guaranteed.

Is Arthrosamid better than hyaluronic acid?

Both treatments may improve symptoms of knee osteoarthritis. Arthrosamid has shown promising longer-term outcomes, but evidence does not establish consistent superiority over hyaluronic acid for every patient.

Can Arthrosamid prevent knee replacement?

Arthrosamid may help patients manage their symptoms, but there is insufficient evidence that it reliably prevents or delays knee replacement surgery.

Is Arthrosamid suitable for severe knee osteoarthritis?

Some patients with advanced osteoarthritis may be considered, although outcomes can be less predictable. Specialist assessment is important to determine whether injection therapy or surgical management is more appropriate.

Is Arthrosamid a permanent injection?

Yes. The hydrogel remains within the joint rather than naturally degrading. This does not mean that pain relief is necessarily permanent.

Arthrosamid Treatment at Pro Sports Medicine, Cardiff

At Pro Sports Medicine, Arthrosamid is delivered within a structured multidisciplinary knee osteoarthritis pathway.

Our approach combines specialist assessment, diagnostic imaging, medical authorisation, ultrasound-guided injection and rehabilitation where appropriate.

Led by experienced clinicians including Dr Julian Chakraverty, Consultant Musculoskeletal Radiologist, the service aims to ensure that Arthrosamid is recommended only when clinically justified.

Clinical Research and References

1. Bliddal H, et al. (2025). A prospective, open-label clinical investigation of a single intra-articular polyacrylamide hydrogel injection in participants with knee osteoarthritis: a 5-year extension study. Journal of Orthopaedic Surgery and Research. Read study.

2. Bliddal H, et al. (2026). Sustained symptom relief and safety over five years following a single intra-articular injection of 2.5% polyacrylamide hydrogel in patients with knee osteoarthritis. Clinical and Experimental Rheumatology. Read study.

3. Contura International. Arthrosamid Instructions for Use, October 2025. Manufacturer’s instructions.

4. NICE Guideline NG226. Osteoarthritis in over 16s: diagnosis and management. Read guidance.

This information is educational and does not replace individual medical advice, assessment or informed consent.