Two Procedures, One Goal: Your Own Cartilage
ChondroFiller® Injection vs
Liquid Cartilage™
ChondroFiller® injection and Liquid Cartilage™ are two distinct procedures invented by Professor Paul Lee, both aimed at preserving and restoring your own cartilage rather than replacing the joint. The injection coats the cartilage surface across the whole joint; Liquid Cartilage™ is a keyhole surgical procedure that regenerates native cartilage at a contained area of damage. Here is what each does, and how we decide which one fits.
Reviewed byProf Paul Lee MBBch, FRCS (Tr & Orth), PhDLast reviewed 1 May 2026Quick Answer
ChondroFiller® injection restores the cartilage surface across the whole joint in a single delivery, with no upper age limit and no defect-size limit. Liquid Cartilage™ is a keyhole surgical procedure that regenerates native cartilage at a contained area of damage and depends on the body’s capacity to grow new tissue. Both are private-pay procedures invented by Professor Paul Lee. The injection is an outpatient appointment from £3,000; Liquid Cartilage™ is a day-case keyhole procedure under general anaesthetic at a flat £9,800. Which one fits depends on the pattern of wear on your MRI and, for the surgical pathway, on your body’s regenerative capacity, which is assessed individually at consultation.
The Headline Difference
ChondroFiller® Injection vs Liquid Cartilage™ — the key difference
ChondroFiller® injection works on the whole cartilage surface of the joint. The collagen scaffold is delivered into the joint under ultrasound guidance and sets in place, coating the cartilage at the load-bearing bone surfaces in a single delivery. Because the procedure does the protective work itself and does not require the body to grow large amounts of new cartilage to be effective, it has no upper age limit and no defect-size limit.
Liquid Cartilage™ is a surgical regeneration procedure. Through a single keyhole operation, the damaged cartilage at a contained area is excavated and a scaffold with cellular co-delivery is placed at that site, so that new native cartilage regrows there over the following months. Because Liquid Cartilage™ is a regenerative procedure, it depends on the body still having the capacity to grow new tissue. Suitability is not really a question of chronological age (years lived), but of biological age: how well your body’s repair and regenerative systems are still working. A patient in their 60s in strong general health can regenerate cartilage better than a less-well patient in their 40s. The frequently-cited 55-year guideline in the literature is a starting point, not a cut-off, and is assessed individually at consultation.
Professor Lee often explains the distinction to patients this way. ChondroFiller® injection is like resurfacing a road where the entire surface is worn but the structure underneath is intact: a fresh protective layer is laid across the whole stretch in a single pass. Liquid Cartilage™ is like regenerating a specific damaged section of road where the road is sound overall but one area is broken through: that area is excavated and rebuilt so the surface regrows. Both are real, lasting interventions; each fits a different starting condition.
Mechanism of Action
How each treatment works
ChondroFiller® injection is delivered in a 30 to 45 minute outpatient appointment under local anaesthetic and ultrasound guidance. The two-part collagen scaffold is mixed in the syringe at the moment of injection and delivered into the joint, where it sets in place over a few minutes and coats the cartilage at the load-bearing bone surfaces.
The patient’s own cells then migrate into the scaffold and lay down new cartilage matrix over the following six to twelve months. No general anaesthetic, no incision, no theatre time.
Liquid Cartilage™ is a keyhole (arthroscopic) day-case procedure performed under general anaesthetic. Professor Lee maps the area of cartilage damage, excavates the damaged cartilage at that site, and delivers the ChondroFiller® scaffold together with medicinal signalling cells (MSCs) into the prepared area.
New native cartilage then regenerates at that site over six to twelve months, integrated with the surrounding tissue. The procedure takes place at our Weymouth Street surgical venue and the patient goes home the same day.
How Long Results May Last
Duration and number of injections
Tissue formation over 6–12 months
Native cartilage regrows over 6–12 months
Direct duration comparison is misleading. The injection coats and protects the cartilage surface across the joint; Liquid Cartilage™ rebuilds native cartilage at a contained site. We measure their success against different goals.
Treatment Course
Number of injections
Typically one injection course, with the box quantity (one, two or three) decided from MRI: one box for most cases, two or three where larger surface area or multiple zones need coverage. A separate future course can be considered if needed.
Liquid Cartilage™ is a single surgical procedure, not a course of injections. The procedure is done once and the regenerated cartilage establishes over the months that follow.
Safety and Infection
Safety considerations
ChondroFiller® injection is a low-risk outpatient procedure. The most serious risk is joint infection, which is rare; we use real-time ultrasound guidance, full sterile technique and routine IV antibiotic cover as an added safety layer.
Liquid Cartilage™ is keyhole day-case surgery under general anaesthetic, with the standard considerations that come with any arthroscopy: anaesthetic risk, joint infection risk (very low under the protocols used), post-operative swelling and a more gradual return to high-impact activity. The Weymouth Street surgical venue and the full anaesthetic team are part of the flat-fee structure.
Patient Selection
Who each treatment may suit
ChondroFiller® injection is appropriate for cartilage wear in the knee, hip, shoulder, ankle, elbow, foot, hand or wrist, whether the wear is a contained focal area or diffuse across the joint surface. There is no upper age limit and no defect-size limit on the injection. It is particularly valuable as a pre-replacement option for active patients in their 60s, 70s and beyond who want to preserve their own joint. See who is suitable for ChondroFiller®?
Liquid Cartilage™ is appropriate where the pattern of damage on imaging is a contained area of cartilage damage in an otherwise healthy joint, and where the patient still has the biological capacity for new cartilage to regenerate. Chronological age (years lived) is not the deciding factor; biological age (how well your tissues still repair and regenerate) is. The 55-year guideline in the literature is a starting point, not a cut-off, and is assessed individually at consultation. See the Liquid Cartilage™ procedure page.
Cost and Value
What each treatment costs
ChondroFiller® injection at London Cartilage Clinic costs from £3,000 for one box, £5,500 for two and £8,000 for three, all-in (consultation, ultrasound, the ChondroFiller® product, the injection and a six-week clinical follow-up). See the ChondroFiller® cost guide.
Liquid Cartilage™ is a flat £9,800, all-in: surgeon, theatre, consultant anaesthetist, the ChondroFiller® scaffold, the MSC co-delivery component and the post-operative follow-up programme. Because it is a single-stage surgical procedure with no laboratory phase and no second operation, it is meaningfully less than two-stage cell-based cartilage repair pathways such as MACI.
The right comparison is which procedure fits the pattern of damage on imaging, not the headline price.
Our Honest Take
When we may recommend each
Cartilage wear in the joint, whether a contained focal area or diffuse across the surface.
Patients of any age, including active patients in their 60s, 70s and beyond.
A pre-replacement option for patients who have been told they need a joint replacement but want to try joint preservation first.
Patients who want to avoid surgery and a general anaesthetic.
A contained area of cartilage damage on MRI in an otherwise healthy joint, with strong biological capacity to regenerate.
Patients seeking regenerated native cartilage at the treated site, rather than a protective coating across the joint surface.
Patients prepared to accept a day-case surgical procedure under general anaesthetic in exchange for the regenerative result.
When Each Is The Wrong Answer
When we would not recommend each
A single contained area of cartilage damage in an otherwise healthy joint with strong biological capacity to regenerate, where Liquid Cartilage™ may be the more targeted intervention.
Untreated joint instability or major malalignment, where the mechanical problem needs to be addressed first.
Diffuse surface wear across the joint, where the injection is the better fit.
Patients whose biological age and overall regenerative capacity make new cartilage regrowth unlikely; the injection is often the more appropriate intervention in this setting.
Patients who decline surgery or general anaesthetic, where the injection is the alternative regardless of damage pattern.
The Bottom Line
In summary
ChondroFiller® injection and Liquid Cartilage™ are two distinct procedures invented by Professor Paul Lee, each appropriate for a different pattern of cartilage damage and different patient needs. The injection restores the cartilage surface across the whole joint with no age or size limit. Liquid Cartilage™ regenerates native cartilage at a contained area through a single keyhole surgical procedure, in patients whose biological capacity supports regeneration. The right answer comes from imaging review and an honest conversation about your goals and your regenerative capacity, not from a default label.
ChondroFiller® Injection vs Liquid Cartilage™
Frequently asked questions
Are ChondroFiller® injection and Liquid Cartilage™ the same procedure?
No. They share the ChondroFiller® collagen scaffold material, but the procedures are fundamentally different. ChondroFiller® injection is a non-surgical, ultrasound-guided outpatient injection that coats the cartilage surface across the whole joint. Liquid Cartilage™ is a keyhole surgical procedure that excavates damaged cartilage at a contained area, delivers the ChondroFiller® scaffold plus MSC co-delivery, and regenerates new native cartilage at that site. Different delivery, different mechanism, different indication.
How do you decide which one is right for me?
Imaging review and a consultation. The pattern of cartilage wear on your MRI is the biggest single input: diffuse wear across the joint surface tends to fit the injection; a contained area of damage in an otherwise healthy joint tends to fit Liquid Cartilage™. Your biological age (not just years lived), your goals, your tolerance for a surgical procedure and your willingness to wait through a regenerative timeline all feed into the recommendation.
I am over 55, can I still have Liquid Cartilage™?
Possibly. The 55-year guideline cited in the literature is exactly that, a guideline. Liquid Cartilage™ depends on the body’s biological capacity to regenerate new cartilage, which is governed by overall health and the condition of your tissues, not just the number of years lived. Many patients above 55 in strong health regenerate well; some below 55 in poorer health do not. Suitability is assessed individually at consultation. If Liquid Cartilage™ is not the right fit, the ChondroFiller® injection is available regardless of age and is often the better answer in this situation.
Do I have to choose between them, or could I have one and then the other?
They are usually offered as alternative pathways for the same joint, not as sequential treatments in immediate succession. Patients who have had ChondroFiller® injection earlier and later develop a specific contained area of damage can in principle be considered for Liquid Cartilage™ at that site, and the reverse can also be considered. The decision is always made at consultation with current imaging.
Why is the injection an outpatient appointment but Liquid Cartilage™ is a surgical procedure?
The two procedures do different things. The injection coats the cartilage surface across the whole joint, which can be delivered under ultrasound guidance in an outpatient appointment. Liquid Cartilage™ excavates the damaged cartilage at a contained area so that new native cartilage can regenerate there, which requires arthroscopic access under general anaesthetic. The different setting reflects what the procedure is actually doing.
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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® is a registered trademark of Meidrix Biomedicals GmbH. London Cartilage Clinic is not affiliated with or endorsed by Meidrix Biomedicals.