Arthrosamid® Injection
Full Patient FAQ

Arthrosamid® at London Cartilage Clinic costs from £3,000 for one box, £5,500 for two boxes, or £8,000 for three boxes, all inclusive of consultation, ultrasound, the product, the published fifteen-step injection protocol and the six-week follow-up. See the full Arthrosamid® cost guide for what is and is not included.

No. Arthrosamid® is not routinely funded by the NHS. Patients access treatment privately on a self-funded basis. Full detail on the Arthrosamid® funding and insurance page.

Arthrosamid® is not currently covered by major UK private medical insurers, including Bupa and AXA. London Cartilage Clinic is a private-pay practice; we can supply an itemised invoice for an independent insurance claim, but reimbursement is between you and your insurer and is unlikely.

Headline prices differ because what is included differs. A cheaper quote often excludes IV antibiotic cover, MRI imaging, clinical follow-up or the ultrasound-guidance and protocol used at higher-cost clinics. See the Arthrosamid® cost guide for the questions to ask before comparing prices.

Most patients settle by bank transfer or card before the procedure. We can discuss finance options on request rather than promoting a specific finance partner. Ask the team during your free discovery call if monthly payment is a consideration.

Based on our independent clinical study with up to 24-month follow-up, benefit is more likely if:

• You are older
• Your arthritis is mild to moderate, not advanced bone-on-bone
• You do not have diabetes
• You receive bilateral knee injections (if both knees are symptomatic)
• You are seeking improvement, not perfection
• Your goal is to delay surgery, not necessarily avoid it forever

We assess this using our structured Arthrosamid® suitability framework.

Arthrosamid® may be less suitable if:

• You have advanced end-stage arthritis
• The knee is severely unstable or deformed
• You are already close to needing knee replacement
• You expect the injection to fully cure your knee

In these situations, benefit may be limited or temporary.

Sometimes yes, sometimes no. Where knee replacement is the clinically appropriate answer, Arthrosamid® is not a substitute. Where surgery has been suggested but you want to explore a non-surgical option first, Arthrosamid® may be appropriate for some patients with mild-to-moderate disease. We will review imaging and tell you honestly which is right for your stage of arthritis.

Advanced bone-on-bone arthritis is one of the situations where Arthrosamid® is less likely to deliver meaningful or lasting benefit. We will not offer the treatment where the chance of useful benefit is low; in many of these cases, the better answer is a knee replacement conversation. We will say so honestly.

Start with the Arthrosamid® suitability self-assessment — eight questions, around three minutes. It is a benefit-weighted scoring system developed from outcomes of over 600 patients treated at London Cartilage Clinic. A free discovery call is the next step if your score suggests Arthrosamid® may be appropriate.

Published outcome data for the knee shows on average two to three years of symptom relief from a single injection. Some patients experience longer benefit, some shorter. Individual outcomes vary by stage of arthritis, body weight and activity level.

Most patients begin to notice improvement at four to six weeks, with continued benefit established by twelve weeks. A short-lived flare in the first few days is common and usually settles without treatment.

No. A minority of patients do not get the expected level of relief. That is one reason suitability assessment matters before treatment — we would rather decline a case than treat someone whose chance of meaningful benefit is low.

If symptoms have not improved by twelve weeks we re-review imaging and clinical findings, discuss whether a further box would be appropriate, and consider alternative pathways. Where end-stage arthritis is the underlying issue, knee replacement may be the better answer; we will say so honestly. Read more on the Arthrosamid® clinical evidence page.

Our Arthrosamid® data comes from an independent, clinician-led clinical study, not sponsored by the manufacturer.

• 269 patients
• 314 knees treated
• Prospective follow-up
• Up to 24 months
• Pain, function, complications, and progression to knee replacement recorded

This allows us to give real-world, balanced advice, rather than relying on marketing claims.

Arthrosamid® has a favourable safety profile when delivered under ultrasound guidance with sterile technique and appropriate patient selection. The most serious risk is joint infection, which is rare. See the dedicated side effects and safety and infection risk pages for the full picture.

Short-term injection-site pain, mild swelling, warmth and joint stiffness in the first few days. These usually settle without treatment. Less commonly, patients report a longer flare lasting a week or two.

Infection is a risk with any joint injection, but with Arthrosamid® it carries greater significance because the material is permanent.

If infection occurs:

• It may be harder to eradicate
• Treatment may be prolonged
• Surgical intervention may occasionally be required

This is why our protocol places exceptional emphasis on infection prevention.

From the very beginning of Arthrosamid® use in the UK, Professor Paul Y.F. Lee adopted a deliberately conservative infection-prevention strategy.

• Professor Lee was the first clinician to perform Arthrosamid® knee injections in the UK
• He has personally performed 1,000+ Arthrosamid® injections
• His wider clinical group has performed over 2,000 injections
• All Arthrosamid® injections are performed with IV antibiotics

Our clinic does not recommend oral antibiotics for Arthrosamid® injections because:

• Oral absorption is variable
• Joint concentrations are unpredictable
• Timing around injection is less reliable
• Effectiveness against biofilm-forming bacteria may be reduced

IV antibiotics provide predictable, immediate protection at the time of injection — which matters with a permanent material.

Yes.

As part of Professor Lee’s specialist protocol, Arthrosamid® injections include a bespoke injection “protocol”, used alongside the hydrogel.

This has been developed and refined based on:

• Scientific principles
• Large-volume clinical experience
• Ongoing review of outcomes and complications

Over time, this approach has been associated with a lower observed complication rate in our own practice.

The exact composition and method form part of our internal protocol and are not shared externally.

This protocol reflects:

• Experience from 1,000+ injections by Professor Lee
• Learning from 2,000+ injections across the group
• Iterative refinement based on outcomes, not manufacturer guidance

Patients do not need to know the technical formulation to understand the purpose, rationale, and safety principles, which are discussed during consultation.

No.

There is no single universal protocol for Arthrosamid®.

Some clinics use:

• Oral antibiotics
• No antibiotics
• Minimal sterile preparation
• Manufacturer-only guidance

Our approach is deliberately more cautious, reflecting experience with permanent materials and long-term outcomes.

Aquamid and Arthrosamid® are both polyacrylamide hydrogel products.

There are published papers describing hydrogel complications, mainly involving:

• Cosmetic or soft-tissue injections
• Large volumes
• Non-joint tissues
• Long-term delayed presentations

These are not directly comparable to modern, image-guided knee injections — but they are important context, and we encourage informed patients to read the literature if they wish.

It means:

• Arthrosamid® is treated as a specialist procedure, not a routine injection
• Safety is prioritised over convenience
• Decisions are based on experience, science, and outcomes
• If you are uncomfortable with IV antibiotics or a bespoke protocol, Arthrosamid® may not be the right option

Manufacturers provide baseline guidance and suggest the use of oral anti-biotics designed to be widely applicable. That does not mean it is optimal for every clinical setting.

Our approach differs because:

• Arthrosamid® is non-biodegradable
• Complications, if they occur, can be more complex
• Published clinical literature shows that context and technique matter
• Long-term outcomes depend on more than the product alone

For these reasons, Professor Paul Y.F. Lee developed a protocol based on:

• Direct clinical experience
• Large-volume outcome review
• Conservative risk management and audit data
• Continuous refinement over time

This includes:

• Mandatory IV antibiotics
• Enhanced sterile technique
• A bespoke injection protocol
• Structured follow-up

Arthrosamid® is a long-acting injection used to manage symptoms of knee osteoarthritis.

It is made from a polyacrylamide hydrogel, a non-biodegradable, biocompatible material that remains inside the knee joint, acting as a long-term cushion and lubricant.

Most injections are absorbed over weeks or months.

Arthrosamid®:

• Is not absorbed
• Remains in the joint long-term
• Can provide symptom improvement lasting many months to up to two years in selected patients

Because it is permanent, patient selection, technique, and safety protocols matter more than with routine injections.

No.

Arthrosamid® does not regenerate cartilage and is not a Stem Cell / Medicinal Signaling Cell treatment.

It helps by:

• Improving joint lubrication
• Reducing mechanical stress
• Improving pain and function

It is a joint-preserving, symptom-modifying treatment, not a cure.

Different goals. Steroid injections give weeks to a few months of relief and are useful for short-term symptom control. Arthrosamid® is a long-acting cushion lasting on average two to three years. Where the clinical question is “can you give me a year or more without surgery?”, Arthrosamid® is generally the more durable answer in suitable patients.

Hyaluronic acid is a resorbable joint lubricant that typically lasts around six months and often requires repeat injections. Arthrosamid® is a non-resorbable polyacrylamide hydrogel designed for long-acting symptom control from a single injection. HA may still be the right first step for some patients; Arthrosamid® is generally the more durable option in suitable cases.

Different mechanisms and different evidence quality. PRP is an autologous biologic; in knee OA the evidence is mixed and duration is typically months. Arthrosamid® is a non-resorbable hydrogel with published outcome data showing on average two to three years of relief from a single injection. PRP may suit some early-stage cases; Arthrosamid® is generally the more durable choice for established osteoarthritis.

In selected patients with mild-to-moderate osteoarthritis, Arthrosamid® may help delay the need for a knee replacement. It is not a substitute for surgery where replacement is clinically appropriate, and it does not regenerate cartilage. We will tell you honestly whether replacement is the better answer for your stage.

Independence means that the clinical study and follow-up were led by clinicians, not by the manufacturer of Arthrosamid®.

This helps ensure that the information used to guide your treatment reflects real clinical experience, rather than marketing claims.

No.

The study was not sponsored, commissioned, or funded by the manufacturer.

This allows outcomes to be discussed openly — including:

• Patients who improve
• Patients who notice limited benefit
• Patients who later progress to knee replacement

Yes — in a positive way.

Because we are not linked to the product:

• Arthrosamid® is not offered routinely
• It is recommended only when it is likely to help
• Other options are discussed honestly when appropriate

If Arthrosamid® is unlikely to provide meaningful benefit, we will say so.

Yes.

Independent clinical studies are commonly used to understand how treatments perform in everyday practice, outside of controlled or promotional settings.

This helps patients understand:

• How long benefits may last
• Who tends to do better
• When alternative treatments may be more appropriate

It means your treatment plan is based on:

• Balanced clinical experience
• Clear discussion of benefits and limitations
• Realistic expectations

Independence supports honest advice — and better decisions.