A single-injection hydrogel treatment considered for suitable knee osteoarthritis after clinical assessment.
No obligation · GP-led assessment firstNot ready to book? Meet Dr Mugerwa →
When stairs become the hardest part of the day?
Arthrosamid® is an intra-articular polyacrylamide hydrogel (iPAAG) used for the symptomatic treatment of knee osteoarthritis in suitable patients. It is 97.5% water and 2.5% cross-linked polyacrylamide, delivered as a single injection into the knee joint space. Clinical follow-up has shown long-lasting symptom relief in selected patients, though response varies and suitability is decided at consultation.
Knee osteoarthritis affects the ordinary parts of life: stairs, shopping, walking, gardening, sleep and time with family. Many people manage well with exercise, weight management, medication or physiotherapy. Others reach a point where they want to discuss injection options before considering a surgical pathway.
Arthrosamid is not suitable for every painful knee. We assess your diagnosis, symptoms, examination findings, previous treatments, medical history and expectations before deciding whether it is the right option for you.
Arthrosamid is not appropriate for every painful knee, and we are direct about that at consultation. These are the three situations in which we most commonly discuss it as a considered option.
Moderate-to-severe knee osteoarthritis
Patients with confirmed osteoarthritic change on imaging — joint space narrowing, cartilage erosion or bone-on-bone grinding — who have not had adequate relief from conservative options such as exercise, weight management, oral medication, physiotherapy, steroid injection or hyaluronic acid.
Patients wishing to delay or avoid knee replacement
Some patients ask about Arthrosamid as a way to delay total knee replacement — to preserve current function, defer the rehabilitation timeline, or simply put surgery off while it remains optional. Whether this is realistic for your knee is decided honestly at consultation.
Patients for whom major surgery is higher risk
For patients deemed higher risk for general anaesthesia or major orthopaedic surgery because of cardiovascular disease, advanced age or significant comorbidities, a non-surgical injection-based option can be valuable to discuss alongside the orthopaedic and anaesthetic view.
The hydrogel is placed in the knee joint space, under local anaesthetic and with ultrasound guidance where appropriate.
Once injected into the knee joint space, the Arthrosamid hydrogel becomes integrated with the soft tissues in the joint lining. The aim is to support symptom relief over the long term. It does not reverse arthritis, and results vary between patients.
We use ultrasound guidance where appropriate to visualise the knee joint and support accurate placement during the procedure. The injection is performed in clinic under local anaesthetic as an outpatient procedure — no hospital stay required.
Your consultation covers whether the pattern of pain, stiffness and function makes Arthrosamid a sensible choice compared with steroid injection, hyaluronic acid, PRF, physiotherapy or onward referral to orthopaedics.
Clinical follow-up shows that some patients report sustained improvements in pain and function for up to three to five years after a single injection. Suitability, individual response and duration of benefit vary, and are discussed honestly at consultation.
A significant reduction in pain still present at one year, with lasting improvements in stiffness and physical function (1)
At least as effective and safe as hyaluronic acid after a single injection, in a separate head-to-head randomised study (3)
Improvements in pain, stiffness and everyday function from that one injection still clearly present half a decade later (2)
Study milestones, not to scale.
Arthrosamid’s manufacturer, Contura, reports the share of treated patients whose knee pain improved, measured on the WOMAC pain score(4).
Of all patients, 14% were unchanged and 13% were worse. Individual results vary.
The durability data is what sets it apart. In a 12-month study, a single ultrasound-guided injection produced a significant reduction in pain that was still present at one year, with lasting improvements in stiffness and physical function(1). Newer five-year follow-up data is even more striking: improvements in pain, stiffness and everyday function from that one injection were still clearly present half a decade later, and remained large enough to be genuinely meaningful in daily life(2). A separate head-to-head randomised study found Arthrosamid at least as effective and safe as hyaluronic acid for at least a year after a single injection(3). Those who respond often notice gradual improvement over the first weeks to months as the gel settles into the joint. Across this long-term research, no safety problems were linked to the gel itself; as with any joint injection, mild and short-lived reactions at the site can occur, and serious side effects are rare.
Individual results vary. Suitability for any treatment is assessed during your consultation.
A long-acting injection doesn't replace the work that keeps a knee going. It can make that work easier to start, and the goals are the everyday ones.
The aim is to support symptom relief over the long term. It does not reverse arthritis, and results vary between patients.
Where pain eases, strengthening the thigh and hip muscles, sit-to-stand practice and a graded walking programme become easier to build, and they matter just as much with a long-acting injection.
Stairs, shopping, walking, gardening and time with family: the ordinary things knee arthritis can shrink are what rehabilitation works towards.
Responses vary, and not every knee is suitable. Exercise remains the foundation of osteoarthritis care, with or without an injection.
We explain each step before treatment so you know what to expect during the procedure, afterwards and if symptoms do not improve as hoped.
We know it can feel difficult to book a procedure when you are not sure what will happen next. Your clinician will explain suitability, risks, recovery and aftercare before treatment goes ahead.
01Choose a consultation online or speak to the clinic if you are not sure which service fits. Most appointments are available within seven days.
02You will have a consultation with the clinician to review your knee symptoms, medical history and suitability before any treatment is offered.
An in-person review with Dr Mugerwa: he will listen to your story and examine the area, which may include an ultrasound scan. You then get an honest recommendation — if treatment is suitable we explain the options, risks and likely outcomes; if it is not, we will tell you and refer you on.
03Arthrosamid® is injected into the knee joint space as an outpatient procedure. You do not need a hospital stay, and ultrasound guidance is used where appropriate.
The procedure itself, followed by tailored aftercare guidance and a clear contact route if anything changes during recovery.
04You receive aftercare advice before leaving clinic, including what to expect after the injection and when to contact us for review.
Download the official Arthrosamid patient brochure and the 3-year follow-up leaflet to learn more about how Arthrosamid may fit into your treatment plan.
Hear from a patient who chose Arthrosamid: a short testimonial about their experience of the treatment and their recovery.
Plays from YouTube
Google review ↗Dr Mugerwa was brilliant — made me feel at ease and kept me informed right through the procedure. Made my Arthrosamid injection pain free. Highly professional and would highly recommend. Thanks.
Stephen Atherton · Arthrosamid knee injection
Arthrosamid is usually discussed later in the journey than the hyaluronic acid injections. The consultation decides which, if any, fits your knee.
| The knee familyThree single-injection routes for knee osteoarthritis | Ostenil PlusHyaluronic acid with mannitolRead about Ostenil Plus → | DurolaneStabilised, cross-linked hyaluronic acidRead about Durolane → | You’re hereArthrosamidPolyacrylamide hydrogel (iPAAG) |
|---|---|---|---|
| What it is | Hyaluronic acid with mannitol, given as a single injection | Non-animal stabilised hyaluronic acid (NASHA): a more cross-linked formulation, given as a single injection | A polyacrylamide hydrogel: 97.5% water and 2.5% cross-linked polyacrylamide, given as a single injection |
| How it is thought to help | Supports joint lubrication and cushioning, working with rather than suppressing inflammation | Works mechanically, restoring some of the cushioning and lubrication lost in osteoarthritis | Becomes integrated with the soft tissues of the joint lining, with the aim of long-term symptom relief |
| Staying power | Mannitol helps protect the hyaluronic acid from oxidative breakdown | Resists breakdown: a slower-clearing gel than standard linear hyaluronic acid | Non-biodegradable: the body does not metabolise or clear it |
| Joints | Knee, shoulder, hip, ankle and base of thumb | Knee (hip and ankle in selected cases) | Knee |
| Most often considered for | Mild-to-moderate osteoarthritis where joint preservation and a non-steroid route are priorities | Knee osteoarthritis when a longer-acting single treatment is the priority | Moderate-to-severe knee osteoarthritis without adequate relief from conservative options |
| Benefit, as reported | Several months in suitable patients; individual response varies | Several months from one injection in suitable patients | Long-lasting in suitable responders; sustained benefit over several years in selected patients |
| Knee price | £280Anterior hip £600 | £350 | £2,400 |
All three follow a GP-led assessment and are given with ultrasound guidance where appropriate; fees include consultation, the procedure and aftercare. Individual response and duration of benefit vary between patients. This table is a guide, not a substitute for clinical assessment. Compare all joint injections →
Assessment, ultrasound, what the fee includes, infection control, the evidence and what happens if it does not help, with a checklist to take with you.
Honest answers to the questions patients most often raise about Arthrosamid in clinic. If yours isn't covered here, ask at your consultation.
Clinical follow-up of patients with knee osteoarthritis has reported sustained reductions in pain and improvements in joint function over several years from a single Arthrosamid injection in suitable responders. Individual response varies, and not every patient achieves this duration of benefit. We discuss your specific likelihood of response — based on your imaging, examination and previous treatment — honestly at consultation.
Arthrosamid is considered for adults with moderate-to-severe knee osteoarthritis who have not had adequate relief from conservative options such as exercise, weight management, oral medication, physiotherapy, steroid injection or hyaluronic acid. It is not suitable for every painful knee. We assess your diagnosis, imaging, examination findings, previous treatments, medical history and expectations before deciding whether Arthrosamid is the right option.
For some patients, Arthrosamid can help delay or potentially avoid total knee replacement. For others, surgery will still be the appropriate path. Arthrosamid does not reverse arthritis or restore lost cartilage. What it offers selected patients is a non-surgical, single-injection option to consider before — or instead of — knee replacement. Your consultation will give you an honest picture of which route fits your situation.
Arthrosamid is a non-biodegradable hydrogel — the body does not metabolise or clear it. Over the weeks following injection, host synovial cells migrate into the gel matrix and it becomes integrated with the joint lining. It is not removed by routine activity, exercise or time. This is also why Arthrosamid is only offered after careful assessment — the decision needs to be a considered one.
Arthrosamid is given as a single outpatient injection under local anaesthetic, with ultrasound guidance used where appropriate to support accurate placement. The appointment typically lasts around 30 minutes. There is no hospital stay. Aftercare guidance is provided before you leave clinic, including what to expect over the following days and when to contact us.
The most commonly reported effects in the days after the injection are short-lived joint pain, swelling or stiffness. Joint infection is a recognised but uncommon risk of any joint injection, which is why we use strict sterile technique and assess for contraindications such as active skin infection. We discuss the specific risks relevant to your situation in detail at consultation so the decision is fully informed.
Arthrosamid is currently a privately-funded treatment in the UK. The Skin & Joint Injection Clinic is an independent, CQC-registered private clinic; you can refer yourself directly. The £2,400 fee includes consultation, the ultrasound-guided injection and aftercare. We're happy to discuss in advance whether Arthrosamid is likely to be a sensible investment for your particular knee.
Arthrosamid’s manufacturer, Contura, reports that 73% of treated patients improved in knee pain, including 79% of those under 70 and 63% of those over 70(1). Five-year follow-up of an earlier study found improvements in pain, stiffness and function still present after a single injection(2). Individual results vary, and suitability is discussed at consultation.
Reference (1): Contura Orthopaedics, response rate by age group (data on file). arthrosamid.com
Reference (2): 5-year extension study, J Orthop Surg Res 2025. link.springer.com
No questions match that search. Ask us directly →
Book a GP-led assessment for an honest view of whether Arthrosamid, another option or an orthopaedic referral is right for your knee.
Useful next steps if you are comparing treatment options at our Wirral clinic.
See how steroid, hyaluronic acid, Arthrosamid and PRF options are selected.
→ 02Short-term anti-inflammatory injections for suitable joints, tendons and bursae.
→ 03Hyaluronic acid injection information for knee osteoarthritis and selected joints.
→
