Kiomedine® knee injection. A new option for knee osteoarthritis.
A single ultrasound-guided injection of a Belgian-developed biopolymer for knee OA. Designed for patients who haven’t responded well to hyaluronic acid, who have advanced OA, or a higher BMI. Now available exclusively in Wales at Acorn Private Clinic, Penarth.
What is Kiomedine®?
Kiomedine®one is a CE-marked medical device for the symptomatic treatment of knee osteoarthritis. It contains carboxymethyl-chitosan (CM-chitosan), a patented, animal-free biopolymer derived from button mushrooms.
Once injected into the knee joint, it works by lubricating the joint, reducing friction between damaged cartilage surfaces, and helping to protect the synovial fluid. This combination can reduce pain and improve function.
Developed in Belgium by Kiomed Pharma, Kiomedine® represents a new class of intra-articular treatment. At Acorn Private Clinic, every injection is delivered under live ultrasound guidance to ensure the product reaches the joint accurately.
Designed for patients who’ve been told “nothing else can help”
Standard hyaluronic acid injections work well for early osteoarthritis. But a large group of patients see little benefit, particularly those with advanced disease or a higher BMI. Kiomedine® was developed for exactly this group.
When other injections haven’t worked
For patients who’ve tried hyaluronic acid (HA) or steroid injections with limited benefit. Kiomedine® works through a different mechanism.
Designed for advanced OA & higher BMI
The PIONEER trial included patients with K&L grade III/IV osteoarthritis, tricompartmental OA, and BMI over 30. These are groups often underserved by traditional treatments.
One injection, 12-month follow-up data
The PIONEER randomised trial followed patients for a full 12 months after a single injection, with sustained symptomatic improvement over the year.
Who can self-refer for Kiomedine®?
If you have a confirmed diagnosis of knee osteoarthritis, you can book a Kiomedine® consultation directly. No GP letter required. Our doctor will assess your suitability before proceeding.
Likely suitable
You may be a good candidate if any of these apply:
- Confirmed knee osteoarthritisDiagnosed by your GP, consultant, or on a recent scan
- Hyaluronic acid or steroid didn’t work wellLimited or short-lived benefit from previous injections
- BMI over 30Studied group where Kiomedine® showed benefit
- Advanced OA, not ready for surgeryYou want to delay or avoid knee replacement
- Not suitable for major surgeryOther medical conditions or personal preference
Not suitable
We may recommend a different approach if:
- No osteoarthritis diagnosisBook an ultrasound or GP assessment first
- Active knee infection or skin infectionNeeds to be fully treated before any joint injection
- Pregnancy or breastfeedingSafety in pregnancy has not been established
- Allergy to chitosan or shellfishAlthough Kiomedine® is animal-free, discuss with us first
- Under 18Not licensed for children
What does the PIONEER trial show?
The PIONEER study (published 2025) was a single-blind randomised controlled trial of 104 patients with refractory knee osteoarthritis. Eligible patients had at least one of: tricompartmental OA, patellofemoral involvement, Kellgren-Lawrence grade III or IV, or BMI > 30 kg/m².
A single Kiomedine® CM-chitosan injection was compared with hyaluronic acid (Hylan G-F 20 / Synvisc-One), with patients followed for 12 months.
The PIONEER trial found significant symptomatic improvement in both groups, with clinically important differences in WOMAC pain reduction favouring CM-chitosan over hyaluronic acid at 12 months in this refractory population.
How the appointment works
From self-referral to injection in a single visit at our Penarth clinic.
Self-refer online
Book a Kiomedine® consultation if you have a confirmed knee OA diagnosis. No GP letter needed.
Assessment
Our doctor reviews your history, examines the knee, and confirms Kiomedine® is right for you.
Ultrasound-guided injection
The injection is delivered with live ultrasound to ensure the product enters the joint accurately.
Recovery & follow-up
Rest the knee for 48 hours, then gradually return to activity. We’ll check in to track your progress.
One transparent price, everything included
One private fee covers your assessment, the Kiomedine® medical device, and the ultrasound-guided injection by an experienced clinician.
£699Kiomedine FAQs
How is Kiomedine different from hyaluronic acid injections?
Kiomedine contains CM-chitosan rather than hyaluronic acid. It is a different molecule with different properties, designed specifically for patients who don’t respond well to hyaluronic acid, including those with advanced osteoarthritis or higher BMI. In the PIONEER trial it showed clinically important pain reduction over 12 months in this group.
Does it really last 12 months?
The PIONEER randomised trial followed patients for 12 months after a single injection and found sustained symptomatic improvement throughout that period. Individual results vary. Some patients respond better than others.
Is the injection painful?
Most patients describe a brief sharp sensation as the needle enters the joint, followed by a feeling of pressure as the product is delivered. We use local anaesthetic skin numbing and live ultrasound guidance to make the procedure as comfortable and accurate as possible. The whole appointment takes around 30 minutes.
What happens after the injection?
You can walk out of the clinic normally. We recommend resting the knee for the first 48 hours. Avoid intense activity, prolonged standing, or heavy lifting. After that, gradually return to your normal routine. Staying active is important to maintain joint health.
Mild discomfort or swelling around the injection site is normal for a few days. Contact us if you experience persistent or worsening pain, significant inflammation, or fever.
Why is ultrasound guidance important?
Ultrasound guidance allows the doctor to see the needle entering the joint space in real time, ensuring the Kiomedine product is delivered into the joint rather than into surrounding soft tissue. Without ultrasound, even experienced clinicians can miss the joint in a significant proportion of cases, particularly in larger or more arthritic knees.
Do I need a referral?
No. If you already know you have knee osteoarthritis, you can self-refer for a Kiomedine consultation. If you’re unsure of your diagnosis or haven’t had imaging, book a knee ultrasound assessment first. We can usually do this in the same visit.
Is Kiomedine safe? What are the side effects?
Kiomedine is a CE-marked medical device with an established safety profile from the PIONEER and APROOVE clinical trials. The most common side effects are temporary: mild pain, swelling, or warmth around the injection site for a few days. As with any joint injection, there is a small risk of infection. Serious adverse events were rare in the trials.
We will discuss your full medical history and any specific risks at your consultation.
Can I have Kiomedine in both knees?
Yes. If both knees are affected by osteoarthritis, both can be treated. We’d typically inject one knee per visit. Two injections (one per knee) is £1,398 total.
Is it covered by health insurance?
Kiomedine is a newer treatment and is not yet routinely covered by UK private health insurers. You may wish to check with your insurer directly. We can provide an invoice for self-claim if needed.
Where is the clinic?
Acorn Private Clinic, 13 Washington Buildings, Stanwell Road, Penarth, CF64 2AD. Free street parking nearby. Around 15 minutes by car from Cardiff city centre and 25 minutes from junction 33 of the M4.
Ready to take the next step?
Self-refer online for a Kiomedine® consultation at Acorn Private Clinic Penarth. The first clinic in Wales to offer this treatment.
Questions? Call us on 029 2199 9300
About this page. Acorn Private Clinic is an officially authorised UK site for Kiomedine® CM-chitosan, and the first clinic in Wales to offer this treatment. Product images and logos are courtesy of Kiomed Pharma (Belgium) and used with permission.
Important. Kiomedine®one is a CE-marked medical device that must be prescribed and administered by an authorised healthcare professional. Information on this page is for general guidance only and is not a substitute for individual medical advice. Suitability is assessed at consultation. Individual results vary. Side effects, contraindications and warnings are discussed at your appointment and detailed in the manufacturer’s instructions for use.