Arthrosamid Injections for Knee Arthritis
Also known as: Arthrosamid knee injections, knee osteoarthritis injections
Arthrosamid is a long-lasting injection treatment for knee arthritis that helps reduce pain and improve mobility without the need for surgery.
What are Arthrosamid injections?
Arthrosamid is an innovative option for people with knee osteoarthritis that involves a single injection of a hydrogel directly into the knee joint. It offers a modern, non-surgical way to manage joint pain when other treatments haven’t provided enough relief.
Arthrosamid is a non-biodegradable hydrogel comprising approximately 97.5% water and 2.5% cross-linked polyacrylamide polymer, forming a soft, gel-like structure that mimics the cushioning found in healthy joint tissue. Once injected, it integrates with the synovial tissue lining the joint capsule, forming an additional shock-absorbing and lubricating layer.
Unlike temporary solutions, Arthrosamid is designed to relieve pain, reduce joint stiffness, and improve mobility in people with mild to moderate knee osteoarthritis. It does not cure or reverse advanced joint damage but provides sustained symptom control. The procedure is minimally invasive and performed as an outpatient appointment under local anaesthesia, typically completed within 15-30 minutes.
What conditions can Arthrosamid injections treat?
Arthrosamid is not suitable for everyone, and careful assessment is needed to ensure it is the right treatment for your knee symptoms.
Knee osteoarthritis is a progressive “wear and tear” condition that affects the protective cartilage covering the ends of the bones within the affected joint. Over time, this leads to pain, stiffness, swelling, and reduced function, particularly common in people over 45 years of age.
Arthrosamid treatment is intended for patients with mild to moderate knee osteoarthritis who experience persistent knee OA pain despite conservative treatments such as physiotherapy, weight management, simple painkillers, and steroid and hyaluronic acid injections. It is also suitable for individuals who have found that alternative treatments have provided only short-term or limited relief.
However, Arthrosamid is not typically recommended for patients with severe end-stage knee osteoarthritis, where knee replacement surgery is likely the most appropriate option. It is also not indicated for inflammatory arthritides, such as rheumatoid arthritis or psoriatic arthritis, or for conditions associated with autoimmune processes. Patients with active joint infection, acute knee trauma, or recent knee surgery are generally advised against this treatment. Some people with underlying medical conditions, including poorly controlled diabetes, coeliac disease, or multiple sclerosis, may require careful evaluation before proceeding.
Although osteoarthritis can affect other joints, such as the hips, hands, and spine, Arthrosamid is currently used only for the knee joint in clinical practice. Your consultant orthopaedic or sports medicine specialist will confirm that Arthrosamid treatment for knee arthritis is appropriate by reviewing your medical history, conducting an examination, and assessing imaging before offering this option.
What are the benefits of Arthrosamid injections?
The benefits of Arthrosamid include long-lasting pain relief and improved mobility with a single injection. For many patients, this treatment reduces the need for repeated joint injections or delays the decision about knee surgery.
Clinically, Arthrosamid injections reduce knee pain at rest and during movement, making activities such as walking, climbing stairs, and daily tasks more manageable. The treatment improves joint cushioning and lubrication, resulting in smoother movement and reduced stiffness, particularly noticeable first thing in the morning or after prolonged sitting. Clinical studies have shown that most patients experience meaningful pain relief within a few weeks, with sustained benefit often lasting 2 to 3 years. Because Arthrosamid is a non-biodegradable hydrogel designed to remain within the joint and integrate with the synovial lining, its effects tend to last much longer than those of many other injectable treatments.
For many patients, Arthrosamid provides a significant reduction in symptoms and may delay the need for knee replacement in suitable candidates.
The convenience of a single treatment session, combined with a relatively quick recovery, means minimal disruption to work, family life, and physical activity, especially when delivered in a same-day setting.
How Arthrosamid compares to other treatments:
| Treatment type | Typical duration of benefit |
| Steroid injections | Weeks to a few months |
| Hyaluronic acid injections | Often 4-6 months |
| Arthrosamid | Up to 2-3 years after treatment |
Before the injection
Initial consultation
At your initial consultation, you’ll meet with an orthopaedic consultant, sports medicine physician, or rheumatologist. They will take a detailed medical history, including your knee symptoms, how long you’ve had joint pain, and any treatments you’ve already tried, such as physiotherapy or medication. The clinician will perform a physical examination of the knee, assessing for signs of soft-tissue involvement, swelling, range of motion, and areas of pain. They will also review any existing imaging, such as X-rays or MRI scans, and may arrange on-site scans if further assessment is needed.
They’ll confirm that knee osteoarthritis is the main cause of your symptoms and make sure Arthrosamid is an appropriate and safe option for you.
This involves checking for things like recent knee surgery or infection, certain medical conditions, medications such as blood thinners, known allergies, or recent dental work that may affect the timing of treatment.
Practical preparation
Fasting is generally not required, as the procedure uses only a local anaesthetic. Patients are advised to wear loose, comfortable clothing or shorts so the knee is easily accessible. It is important to arrange transport home, as driving on the day of the injection is usually not recommended.
Regarding medication management, if you take blood thinners such as warfarin, you may need tailored advice on whether to pause or adjust them. Usual daily medications can often be continued, but this should be confirmed during your consultation.
During the injection
Arthrosamid injections are performed as a day-case procedure in a dedicated treatment room, so you can go home the same day. When you arrive, the clinician will check in with you, confirm your consent, and answer any last-minute questions so you feel comfortable before starting.
The skin around your knee is carefully cleaned, and a local anaesthetic is used to fully numb the area. You may experience a brief stinging sensation at first, but this usually settles quickly. Ultrasound is usually used throughout the procedure to allow the clinician to visualise the knee joint in real time and guide the injection safely and accurately to the correct location.
Once the area is numb, a fine needle is gently inserted into the knee joint. If there is any excess fluid causing swelling, this may be drained first. The Arthrosamid hydrogel is then slowly injected into the joint, where it begins to settle and work within the joint lining.
The injection itself usually takes around 15 to 20 minutes. Including preparation and a short observation period afterwards, most people spend 30 to 60 minutes in the clinic. Patients commonly describe a feeling of pressure or fullness in the knee rather than pain. If you do feel uncomfortable at any point, additional local anaesthetic can be given.
After the injection, the needle is removed, a small dressing is applied, and you’ll be encouraged to stand and walk a short distance before heading home. Most people are able to walk out of the clinic comfortably.
After the injection
Immediately after the procedure, it is important to keep the small dressing in place for the time advised by your clinician, usually 24 to 48 hours, and to keep the area clean and dry. Mild swelling, warmth, or soreness around the knee is common for a few days, and over-the-counter pain relief such as paracetamol is often sufficient unless contraindicated. Applying ice packs wrapped in a cloth for short periods can help reduce discomfort, but direct contact of ice with the skin should be avoided.
Regarding activity, patients should avoid driving for the rest of the day and until the knee feels comfortable and fully controllable. It is also recommended to refrain from heavy lifting, running, squatting, and high-impact sports for several days to a couple of weeks, gradually increasing activity as comfort improves. Low-impact movement, such as short walks, is usually encouraged to promote circulation and maintain joint mobility.
In terms of the expected timeline for benefits, some people notice early pain relief within around 4 weeks, but for most patients, improvement builds gradually over 4 to 12 weeks. The positive effect may last up to 3 years in many patients, though individual responses vary, and not everyone experiences the same degree of benefit.
Risks & complications
Common, usually short-lived side effects:
- Temporary increase in knee pain or joint stiffness.
- Mild swelling, warmth, or a feeling of fullness in the joint.
- Minor bruising or tenderness at the injection site.
Less common but important risks and complications:
- Joint infection (septic arthritis), which may be signalled by severe pain, marked swelling, redness, fever, or feeling unwell. This is a medical emergency requiring urgent assessment.
- Allergic reaction to the injectate or antiseptic agents, presenting as rash, itching, or breathing difficulty.
- Persistent inflammation (synovitis) or prolonged pain that does not settle after several weeks.
- Bleeding into the joint, particularly in people taking blood-thinning medications.
Appointment and Treatment Plan
Initial consultation
Your Arthrosamid journey begins with a consultation with an orthopaedic or sports medicine specialist. During this appointment, your clinician will discuss your knee symptoms, how long you’ve been experiencing pain, and which treatments you’ve already tried. They’ll examine your knee and review any imaging, such as X-rays or MRI scans, to confirm that knee osteoarthritis is the main cause of your symptoms and that Arthrosamid is an appropriate option for you.
Treatment planning
If Arthrosamid is suitable, your clinician will explain the procedure in detail, including the expected benefits, potential risks, and alternative treatment options. You’ll have the opportunity to ask questions and decide whether you’d like to proceed. Medication use, including blood thinners, will be reviewed, and you’ll be given clear guidance on how to prepare for the injection.
The injection
The Arthrosamid injection is performed as a day-case procedure under local anaesthetic. The skin around your knee is cleaned, and the area is numbed to keep you comfortable. A fine needle is then used to inject the hydrogel directly into the knee joint. The procedure itself usually takes around 15–20 minutes. Most patients describe a feeling of pressure or fullness rather than pain.
After the injection
You’ll usually be able to walk out of the clinic shortly after the injection. It’s advised to rest the knee for the remainder of the day and avoid strenuous activity for a short period. Mild swelling or soreness around the knee is common for a few days and can usually be managed with simple pain relief if needed.
Recovery and results
Some people notice improvement within a few weeks, but for most patients pain relief builds gradually over 4–12 weeks. Many experience long-lasting symptom relief for up to 2–3 years. Your clinician may recommend physiotherapy or gentle exercise alongside Arthrosamid to help maximise and maintain your results.
Experts
We are proud to provide patients with access to a wide range of clinicians, chosen specifically for their knowledge and reputation in their area of expertise. Our experts align with our values: putting you at the centre of your care and educating you on your options at each step of the journey. We encourage you to learn more about our clinicians and how they can help you below. As always, please contact our patient services team if you require any additional information.
We offer 3 ways to pay for your treatment
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Our payment options are designed to offer you easy access to our treatments and services. You can choose to pay on the day, spread the cost, or use your private medical insurance.
Our patient services team will guide you through the process, providing clear costs and support throughout your course of treatment so you can focus on the thing that matters most – your health.
Whether you pay in advance, spread the cost, or use your private medical insurance, rest assured you will be receiving exceptional care 365 days a year.
Pay in Advance
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We provide transparent pricing from your initial consultation to the completion of your treatment so you know where your stand, every step of the way.
We accept all major debit and credit cards, as well as Apple Pay for UK residents. Please note that we do not accept cash or cheques.
Spread the cost monthly
Paying for your treatment at One Stop Healthcare can be spread monthly from 12 to 60 months, rather than paying in one go.
With an upfront 10% deposit paid, via our Financial partner Chrysalis Finance, we offer various flexible terms to enable you to spread the cost, including 12-months at 0% APR. Click here to find out more.
Monthly payments need to be linked to an One Stop Healthcare treatment over £385 and is subject to a 14-day ‘cooling-off’ period before any treatment can start.
Your on-going payments will be made directly between Chrysalis and yourself. It’s that simple.
Pay using PMI
We are recognised by all major health insurance companies and with our extensive range of services, there are lots of benefits to using your insurance with us. Our patient services team is here to answer any questions you may have about using your private health insurance with us.
Please bring along your policy details including your scheme details, membership or policy number, expiry date and confirmation of eligibility to claim (i.e. your authorisation number). If you do not have these details with you, we will require payment from you on the day. Patients are liable for any amounts not settled by their insurer.
FAQs
Arthrosamid injections have been shown to provide effective, long-lasting relief for many patients with knee osteoarthritis. Clinical trials and patient experience suggest that many people notice a significant reduction in knee pain within 4 weeks of treatment. This improvement typically continues to build over the following weeks, with benefits lasting 2 to 3 years.
The non-biodegradable hydrogel used in Arthrosamid integrates with the synovial lining of the knee joint, providing sustained cushioning and lubrication to help reduce joint stiffness and improve mobility. Although individual responses may vary, Arthrosamid is considered a valuable treatment option for those who have not found sufficient relief from conservative treatments such as physical therapy, medications, or other injections, including steroids or hyaluronic acid.
The effects of a single Arthrosamid injection can last for an extended period, often up to two to three years after treatment. This longevity is due to the hydrogel’s unique properties, which are non-biodegradable and designed to integrate with the knee’s synovial tissue, providing continuous cushioning and lubrication. Compared with other injectable treatments, such as hyaluronic acid injections, which typically last four to six months, Arthrosamid offers a much longer duration of symptom relief. Patients usually notice some pain relief within a few weeks, but the full benefits may take up to twelve weeks to become apparent. This long-lasting effect can delay the need for knee replacement surgery and reduce the frequency of repeat injections, making Arthrosamid a convenient and minimally invasive treatment for managing moderate knee osteoarthritis.
No, Arthrosamid is not a steroid injection. It is a non-biodegradable hydrogel that works by improving joint cushioning and lubrication rather than reducing inflammation. This makes it a longer-lasting option compared to steroid injections for some patients.
Most patients are able to walk immediately after an Arthrosamid injection and return home the same day. Light activity is usually encouraged, although strenuous exercise and high-impact activity should be avoided for a short period as advised by your clinician.
For some patients, Arthrosamid injections can help delay the need for knee replacement surgery by reducing pain and improving function. It does not prevent arthritis progression, but it may provide symptom relief that allows people to remain active for longer before considering surgery.