Two Complementary Injections
ChondroFiller® and
Arthrosamid®
Both are clinic-delivered, ultrasound-guided injections, and they target different parts of the joint. ChondroFiller® coats the cartilage at the load-bearing bone surfaces; Arthrosamid® integrates into the synovial lining. Because they address different anatomical structures and different sources of joint pain, we frequently deliver both in a single session as the most complete option for patients with both forms of trouble. Here is what each does on its own, and how they combine.
Reviewed byProf Paul Lee MBBch, FRCS (Tr & Orth), PhDLast reviewed 1 May 2026Quick Answer
ChondroFiller® and Arthrosamid® work on different parts of the same joint, and they complement each other rather than compete. ChondroFiller® coats the cartilage at the load-bearing bone surfaces and supports natural cartilage restoration over six to twelve months (£3,000 to £8,000 depending on box quantity). Arthrosamid® is a hydrogel that integrates into the synovial lining and cushions the joint from the inside, with two to three years of symptom relief on average from a single £3,000 injection. For many patients with both worn cartilage and an inflamed lining, we deliver both in a single appointment as the most complete option. The right choice, or combination, depends on what your MRI shows.
The Headline Difference
ChondroFiller® vs Arthrosamid® — the key difference
ChondroFiller® is a collagen scaffold delivered onto the cartilage at the load-bearing bone surfaces, where it coats and restores the cartilage layer; the body’s own cells then migrate in and lay down new matrix over six to twelve months. Arthrosamid® is a polyacrylamide hydrogel that integrates into the synovial lining of the joint and cushions it long-term; it is mechanical, not regenerative. The two treatments target two anatomically distinct parts of the same joint, which is why they can be combined together in a single session for patients with both forms of trouble.
Mechanism of Action
How each treatment works
ChondroFiller® is a sterile type I/III collagen scaffold injected as a liquid into the joint under ultrasound guidance. Within minutes it sets in place and coats the cartilage layer at the load-bearing bone surfaces, restoring the surface across the joint in a single delivery.
The patient’s own cells then migrate into the scaffold and lay down new cartilage matrix over the following six to twelve months. ChondroFiller® coats, protects and supports natural cartilage restoration; it does not mechanically cushion the joint.
Arthrosamid® is a 2.5% polyacrylamide hydrogel injected into the joint cavity under ultrasound guidance. The gel integrates into the synovial membrane and acts as a long-term cushion.
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.
How Long Results May Last
Duration and number of injections
Tissue formation over 6–12 months
2–3 years per injection
Direct duration comparison is misleading. ChondroFiller® coats and restores the cartilage surface across the joint; Arthrosamid® controls symptoms by cushioning the synovial lining. We measure their success differently.
Treatment Course
Number of injections
Typically one injection course, with the box quantity (one, two or three) decided from MRI: one box treats most defects up to roughly 2 cm², two or three for larger or multi-zone defects. A second course is rarely needed if the original tissue establishes.
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.
Safety and Infection
Safety considerations
Both are outpatient injections with low overall complication rates. The most serious risk for either treatment is joint infection, which is rare. London Cartilage Clinic uses the same conservative protocol for both: real-time ultrasound guidance, full sterile technique and a routine IV antibiotic cover. For Arthrosamid® this addresses a known elevated infection signal in the literature; for ChondroFiller® the infection risk is genuinely low and the IV cover is added safety, not essential mitigation.
ChondroFiller® placement is defect-specific, so ultrasound guidance is not optional — it is the difference between filling the defect and depositing scaffold into the joint space. See Arthrosamid® infection risk and prevention for the injection-specific protocol that applies to both products.
Patient Selection
Who each treatment may suit
ChondroFiller® coats the load-bearing cartilage surface of the joint, whether the wear is a contained focal defect or diffuse across the surface. There is no upper age limit and no defect-size limit on the injection. It is delivered to the cartilage at the ends of the bones, the part of the joint where bone meets bone under load. See who is suitable for ChondroFiller?.
Arthrosamid® is for patients with established knee osteoarthritis who want long-lasting symptom relief without surgery, where an inflamed synovial lining is driving a meaningful part of the pain. See who is suitable for Arthrosamid?
Many patients have both worn cartilage at the bone surfaces and an inflamed, irritated synovial lining at the same time. In those cases we routinely deliver both injections in a single appointment as the most complete option, addressing two different sources of joint pain in one session. Imaging review at consultation tells us which combination is right.
Cost and Value
What each treatment costs
At London Cartilage Clinic, ChondroFiller® costs from £3,000 for one box, £5,500 for two and £8,000 for three. The box requirement is set from MRI, not by upsell. See the ChondroFiller® cost guide.
Arthrosamid® at LCC is 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.
Both prices are all-in for the named clinician, named injection, named follow-up. The right comparison is clinical fit, not headline number.
Our Honest Take
When we may recommend each
You have cartilage wear visible on MRI, whether a contained focal defect or diffuse across the joint surface.
You want a treatment that coats and protects the cartilage at the load-bearing bone surfaces, with no upper age limit and no defect-size limit.
You want a meaningful intervention before, or instead of, considering joint replacement, including as part of a combined session with Arthrosamid® where the synovial lining is also driving symptoms.
You have established knee osteoarthritis with whole-joint symptoms.
You want long-lasting symptom relief from a cushion that integrates into the synovial lining, with realistic expectations of what an injection can and cannot do.
You want to delay more invasive surgery, on its own or combined with ChondroFiller® in the same session if your cartilage surface is also worn.
When Each Is The Wrong Answer
When we would not recommend each
A single contained focal defect in an otherwise healthy joint with strong biological capacity for regeneration, where the Liquid Cartilage™ surgical regeneration pathway may be a more targeted intervention.
Untreated joint instability or major malalignment, where the mechanical problem needs to be addressed first.
Active infection or unwillingness to accept the conservative safety protocol.
A patient looking for cartilage restoration: Arthrosamid® works on the synovial lining, not the cartilage at the bone surfaces. ChondroFiller® is the right answer for that, and we can combine the two in a single session where both forms of trouble are present.
End-stage disease where joint replacement is the clinically appropriate path.
Patients expecting Arthrosamid® to regenerate cartilage; that is not what the treatment does.
The Bottom Line
In summary
ChondroFiller® and Arthrosamid® are both ultrasound-guided clinic injections, but they work on different parts of the joint. ChondroFiller® coats the cartilage at the load-bearing bone surfaces; Arthrosamid® integrates into the synovial lining. For many patients with osteoarthritis the most complete answer is both, delivered together in a single session. Where the pattern of damage points to one alone, we recommend just that one. Where a surgical pathway is a better fit, we say so honestly, and the Liquid Cartilage™ pathway is one of the options we will discuss.
ChondroFiller® vs Arthrosamid®
Frequently asked questions
Can I have both ChondroFiller® and Arthrosamid® in the same session?
Yes, and patients frequently do. The two treatments target different parts of the joint: ChondroFiller® coats the cartilage at the load-bearing bone surfaces, while Arthrosamid® integrates into the synovial lining. Because they address different anatomical structures and different sources of joint pain, they complement each other rather than compete, and we routinely deliver both as injections in a single appointment for patients with both forms of trouble. Imaging at consultation tells us which combination is the right fit.
Which one regenerates cartilage?
ChondroFiller® supports natural cartilage regeneration by providing a scaffold for the body’s cells to lay down new matrix over six to twelve months. Arthrosamid® does not regenerate cartilage; it is a mechanical hydrogel cushion that integrates into the synovial membrane.
Which has more clinical evidence?
Both have published cohort data. Arthrosamid® has larger registry cohorts in knee osteoarthritis at two to three years; ChondroFiller® has cartilage-specific outcome data (IKDC, Harris Hip Score, MOCART MRI) and over 19,000 cases of clinical use across joints. See the ChondroFiller® clinical evidence page.
Why is ChondroFiller® priced by boxes when Arthrosamid® is a flat fee?
A ChondroFiller® scaffold has to fill the defect; box quantity is set by defect size on MRI (one, two or three). Arthrosamid® is dosed by joint, not by defect size, so a single box covers the standard knee injection.
I have arthritis with one bad spot, which is right for me?
That is genuinely a consultation question, and the honest answer is often both. ChondroFiller® addresses cartilage wear at the bone surfaces (including a focal bad spot and any wider surface wear at the same time), while Arthrosamid® addresses the inflamed synovial lining that drives a lot of the symptoms in an arthritic joint. We review the MRI and recommend whichever combination fits your joint, and we say so honestly when one alone is the right answer.
Is one safer than the other?
They have similar safety profiles. Both are outpatient injections delivered under ultrasound with full sterile technique. The most serious risk for either is joint infection, which is rare. LCC uses the same routine IV antibiotic cover for both — for Arthrosamid® this addresses a known elevated infection signal in the literature; for ChondroFiller® it is layered safety on top of an already low infection risk.
Book a ChondroFiller® Assessment – London
Natural cartilage regeneration starts with the right defect, the right operator, and the right plan.
Learn More about ChondroFiller
Deep dive into our clinical resources and patient guides.
Cost in the UK
ChondroFiller® cost in the UK from £3,000, what is included and why prices vary.
Suitability
Who is suitable for ChondroFiller® as an injection, and who may need caution.
Clinical Evidence
IKDC, Harris Hip Score and MOCART MRI outcomes for ChondroFiller® cartilage regeneration.
Self-Assessment
Five-question ChondroFiller® pathway self-assessment for Prevention, Regeneration, Combination, or Support.
In London
Private ChondroFiller® cartilage repair at our Harley Street clinic.
Liquid Cartilage™ Surgery
Our proprietary keyhole-surgery technique combining ChondroFiller® with MSC co-delivery in a single procedure, for larger or more complex cartilage defects. £9,800.
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ChondroFiller® Injection
Cartilage Regeneration Overview
ChondroFiller® is a registered trademark of Meidrix Biomedicals GmbH. London Cartilage Clinic is not affiliated with or endorsed by Meidrix Biomedicals.