A Careful, Honest Comparison
Arthrosamid® vs
Knee Replacement
Arthrosamid® is not a substitute for knee replacement where replacement is clinically appropriate. In suitable patients with mild-to-moderate disease, it may help delay more invasive surgery when appropriate. Here is the honest comparison.
Reviewed byProf Paul Lee MBBch, FRCS (Tr & Orth), PhDLast reviewed 1 May 2026Quick Answer
Arthrosamid® is not a substitute for knee replacement where replacement is clinically appropriate. In carefully selected patients with mild-to-moderate knee osteoarthritis, Arthrosamid® may help patients remain active and delay knee replacement, not necessarily avoid it forever. In advanced bone-on-bone arthritis the underlying disease may progress regardless, and replacement is often the better answer. The right choice is decided at consultation with imaging review.
The Headline Difference
Arthrosamid® vs Knee Replacement — the key difference
Knee replacement removes and replaces the joint surface — it is a definitive, one-off operation for end-stage arthritis with a strong evidence base. Arthrosamid® is a non-surgical injectable cushion that treats symptoms without altering the underlying joint. Where the joint is still salvageable, Arthrosamid® can help patients delay surgery when appropriate; where the disease is end-stage, replacement is usually the right answer.
Mechanism of Action
How each treatment works
Arthrosamid® is a polyacrylamide hydrogel injected into the knee joint under ultrasound guidance. The gel integrates into the synovial membrane, acting as a long-term cushion. It is not absorbed, not metabolised and not regenerative.
It works mechanically by cushioning and lubricating the joint. It does not regenerate cartilage, does not reverse arthritis and does not alter the joint surface.
Total or partial knee replacement is a definitive surgical procedure in which the worn joint surfaces are removed and replaced with metal and polyethylene implants. The underlying arthritic surface is no longer present.
Modern knee replacements have well-documented long-term outcomes. Most patients experience substantial and durable pain relief and functional improvement.
How Long Results May Last
Duration and number of injections
2 to 3 years, per injection
15 to 20 years typically
Direct comparison of duration is misleading: Arthrosamid® treats symptoms in a joint that still has its own surface; replacement is a definitive operation that replaces the surface. They sit at different points on the treatment ladder.
Treatment Course
Number of injections
One injection is the standard treatment course in suitable patients. A further Arthrosamid® treatment may be considered at a future date if symptoms recur and the joint is still suitable.
Knee replacement is a one-off operation. Revision surgery is sometimes needed years later in younger or higher-demand patients, but for most patients a single replacement lasts the rest of their life.
Safety and Infection
Safety considerations
These are very different procedures with very different risk profiles. Arthrosamid® is an outpatient injection with a low complication rate; the most serious risk is joint infection, which is rare. Knee replacement is major surgery with the risks inherent in any joint replacement — infection, venous thromboembolism, anaesthetic complications, and a rehabilitation period of weeks to months.
Arthrosamid® at London Cartilage Clinic uses routine IV antibiotic cover and ultrasound guidance. Knee replacement is delivered through hospital admission with the standard peri-operative care that surgery requires. See Arthrosamid® infection risk and prevention for the injection-specific protocol.
Patient Selection
Who each treatment may suit
Knee replacement is the right answer for end-stage osteoarthritis — bone-on-bone change, severe deformity, persistent symptoms despite conservative measures, and a clinical and imaging picture that supports it. We will say so honestly when this is the case.
Arthrosamid® is appropriate for patients with mild-to-moderate disease who want to delay more invasive surgery when appropriate, have realistic expectations and are willing to accept the safety protocol. It can help some patients delay knee replacement at the right time, but it is not a substitute where replacement is clinically appropriate. See who is suitable for Arthrosamid?.
Cost and Value
What each treatment costs
At London Cartilage Clinic, Arthrosamid® costs from £3,000 for one box, inclusive of consultation, ultrasound, the product, the fifteen-step injection protocol and the six-week follow-up. See the Arthrosamid® cost guide.
Private knee replacement in the UK typically costs £15,000 to £25,000 depending on the provider, implant type and complexity. NHS knee replacement is available for clinically appropriate cases, though waiting times vary. The cost difference is meaningful, but the more important comparison is clinical: each treatment is right for a different stage of disease.
Our Honest Take
When we may recommend each
You have established knee osteoarthritis with mild-to-moderate cartilage wear.
You want to delay more invasive surgery when appropriate, with realistic expectations and willingness to accept the safety protocol.
Surgery has been suggested but you want to explore a non-surgical option first, and the imaging supports a non-surgical attempt being reasonable.
End-stage bone-on-bone osteoarthritis with persistent symptoms despite conservative care.
Significant deformity, instability or mechanical failure of the joint that an injection cannot address.
A clinical and imaging picture that points clearly to definitive surgery as the better answer.
When Each Is The Wrong Answer
When we would not recommend each
End-stage bone-on-bone arthritis where Arthrosamid® is unlikely to deliver meaningful benefit and replacement is the appropriate path.
Patients expecting Arthrosamid® to prevent knee replacement — that is not what the treatment can promise.
Active infection or unwillingness to accept the conservative safety protocol.
Mild-to-moderate osteoarthritis where conservative measures and a non-surgical injection have not yet been tried.
Significant comorbidity that makes major surgery a poor risk-benefit choice, where a less invasive option remains reasonable.
Patients who want to delay surgery for a defined period (training, work, family commitments) and have a joint that is still suitable for a non-surgical attempt.
The Bottom Line
In summary
Arthrosamid® and knee replacement sit at different points on the treatment ladder for knee osteoarthritis. Arthrosamid® may help patients delay knee replacement, not necessarily avoid it forever, and it is not a substitute where replacement is clinically appropriate. Where the joint is still salvageable, Arthrosamid® can be a reasonable step. Where the disease is end-stage, replacement is usually the right answer. We will tell you honestly which one fits your case.
Arthrosamid® vs Knee Replacement
Frequently asked questions
Can Arthrosamid® help me avoid a knee replacement?
In carefully selected patients with mild-to-moderate disease, Arthrosamid® may help delay knee replacement, not necessarily avoid it forever. It is not a substitute where replacement is clinically appropriate, and we will not promise that it prevents the need for surgery. The right answer depends on the imaging and clinical picture at consultation.
How long can Arthrosamid® delay knee replacement surgery?
Published outcome data shows on average two to three years of symptom relief from a single Arthrosamid® injection in suitable patients. For some patients this defers the need for surgery further; for others, the underlying disease progresses and replacement becomes the right answer at a later point. We will give you a written, case-specific view at consultation.
Will Arthrosamid® make a future knee replacement more difficult?
Current evidence does not show that prior Arthrosamid® materially complicates a subsequent knee replacement. The hydrogel sits in the synovial membrane; the surgical field for replacement is well established. We will discuss this directly if a future replacement looks likely.
I have been told I need a knee replacement. Should I try Arthrosamid® first?
Sometimes yes, sometimes no. Where surgery has been suggested but you want to explore a non-surgical option first, and the imaging supports a non-surgical attempt being reasonable, Arthrosamid® can be appropriate. Where the joint is genuinely end-stage, replacement is the better answer and we will say so honestly.
Does Arthrosamid® regenerate cartilage or reverse arthritis?
No. Arthrosamid® is a long-acting cushion, not a regenerative treatment, and not a cure. It does not regenerate cartilage or reverse the underlying arthritis. It manages symptoms while the underlying disease continues to be what it is. See the Arthrosamid® clinical evidence page.
Is knee replacement available on the NHS?
Yes, knee replacement is a routine NHS procedure for clinically appropriate cases, though waiting times vary. Arthrosamid® is not routinely funded by the NHS. See the Arthrosamid® funding and insurance page for the private-pay context.
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Learn More about Arthrosamid
Deep dive into our clinical resources and patient guides.
Cost in the UK
Arthrosamid® cost in the UK from £3,000, what is included and why prices vary.
NHS & Insurance
Is Arthrosamid® available on the NHS or private insurance?
Suitability
Who is suitable for Arthrosamid® — and who may need caution.
Clinical Evidence
Real-world outcome data and what the evidence means for patients.
Side Effects & Safety
Arthrosamid® side effects, risks, complications and clinical context.
Infection Risk
Arthrosamid® infection risk, prevention protocol and IV antibiotic policy.
In London
Private Arthrosamid® treatment at our Harley Street clinic.
Self-Assessment
Eight-question Arthrosamid® suitability self-assessment tool.
Full FAQ
Arthrosamid® patient FAQ across cost, suitability, safety and comparisons.
vs Hyaluronic Acid
Arthrosamid® compared to hyaluronic acid injections.
vs PRP
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vs Steroid Injection
Arthrosamid® compared to corticosteroid injection.
vs Knee Replacement
Where Arthrosamid® may help delay surgery — and where it cannot.
Arthrosamid® Injection
Comprehensive Overview
Arthrosamid® is a registered trademark of Contura A/S. London Cartilage Clinic is not affiliated with or endorsed by Contura A/S.