Arthrosamid® (PAAG)
Injection – Full Patient FAQ

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

It is made from polyacrylamide hydrogel (PAAG) — 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 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.

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 a structured PAAG-8+ patient selection 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.

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.

Aquamid and Arthrosamid® are both PAAG-based products.

There are published papers describing PAAG 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.

Infection is a risk with any joint injection, but with PAAG 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 600+ 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 PAAG.

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 600+ 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.

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 PAAG 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

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.