Which injection treatment might suit my condition?
No injection is best for everyone with knee osteoarthritis. Compare Arthrosamid, PRP, hyaluronic acid and corticosteroids below. The decision starts with the diagnosis, severity, symptoms, previous care and the activities you want to regain.
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An injection may ease symptoms, but is not proven to replace lost cartilage. Exercise, rehabilitation, activity adjustment and weight management where appropriate remain central. Choosing not to have an injection can also be appropriate.
Comparing injections for knee osteoarthritis
On a narrow screen, scroll the table sideways. Times are broad indications from research and practice, not a personal prediction. Not everyone improves.
| Question | Arthrosamid | PRP / high-dose PRP | Hyaluronic acid (HA) | Corticosteroids |
|---|---|---|---|---|
| How it works | Non-biodegradable polyacrylamide hydrogel integrates with the joint lining. Aims to reduce pain and improve movement; it does not create cartilage. | Your platelets release signalling substances that may influence the joint environment. Cartilage regeneration has not been established. | Adds hyaluronic acid to joint fluid, aiming to improve lubrication and symptoms. | Suppresses inflammation within the joint to temporarily reduce pain and swelling. |
| When to discuss it | Persistent symptoms from knee osteoarthritis, after reviewing previous care, expectations and contraindications. | Mainly early to moderate knee osteoarthritis when exercise and other conservative care have not helped enough. | For selected patients wishing to discuss another injection option. The expected benefit is uncertain. | A painful flare, or temporary support for exercise when other pain treatment is insufficient. |
| Evidence and professional advice | A trial against HA and follow-up to 3 and 5 years. A smaller evidence base; not an established preferred treatment for everyone. | ESSKA-ORBIT and ESSKA-ICRS support selected use. Average outcomes often favour PRP over HA, but studies disagree. AAOS rates the evidence as limited. | Many studies with mixed results. AAOS advises against routine use; NICE advises against use for osteoarthritis. An individual assessment is needed. | AAOS and NICE support selected use for short-term relief. It does not stop osteoarthritis. |
| When might it start working? | Gradually; assessment may take up to about 12 weeks. Early pain relief does not predict the final result. | Gradually over weeks; in this practice, results are usually assessed at about 8 weeks. | Gradually over several weeks; average benefit in research was often clearest around 8 weeks. | Often within a few days. Local anaesthetic, if used, works earlier but wears off sooner. |
| How long might benefit last? | Some participants in follow-up studies retained improvement at 3–5 years. This is not a typical or guaranteed duration for everyone. | Responders may benefit for several months; studies often assess 6–12 months. There is no fixed duration. | If helpful, relief may last several months; research describes benefit up to about 6 months. | Usually short term: NICE gives approximately 2–10 weeks; it can be shorter or longer. |
| Number and preparation | One treatment with 6 ml, local anaesthetic and preventive antibiotics according to the protocol. | Requires a blood sample. Here, usually 3 injections 2 weeks apart; high-dose PRP/ACP MAX may be discussed as one planned injection. | One injection or a course, depending on the product. No blood sample required. | Usually one injection followed by reassessment. No automatic repeat course. |
| Possible side effects | Pain, swelling and stiffness, sometimes lasting weeks to months. Infection is rare but serious. | Temporary pain, swelling, stiffness or bruising; rarely infection. Using your own blood does not make the injection risk-free. | Pain or swelling; sometimes a marked inflammatory reaction without infection. Rare infection or allergic reaction. | Temporary pain flare, flushing or raised blood glucose; occasional skin colour change or thinning of tissue beneath the skin. Rare infection. |
| Long-term safety | The gel remains in the joint. Follow-up is encouraging, but large long-term comparisons and information on rare late problems remain limited. | No established structural repair. Available studies cannot guarantee the absence of rare or late harm. | No proven protection against osteoarthritis progression. Repeat use and adverse effects require an individual, product-specific assessment. | One important trial of injections every 3 months for 2 years found greater cartilage loss. It does not show that a single injection causes the same harm. |
What do we discuss about your knee?
- Identify the source of pain first. Not every painful knee has osteoarthritis. Examination and imaging when needed help establish the diagnosis and severity.
- Review your symptoms and previous care. A swollen, painful flare calls for a different assessment from persistent pain when walking. We review exercises, medication, earlier injections and daily limitations.
- Weigh benefits, uncertainties and risks. We discuss suitable options, preferences, costs, procedure location and a realistic goal. An assessment appointment does not automatically include an injection.
- Agree on a plan and review date. You receive advice on preparation, temporary activity adjustment, rehabilitation and what to do if improvement does not occur.
Frequently asked questions
Is PRP better than hyaluronic acid?
Several studies report better average pain and function outcomes with PRP, particularly after several months. This does not apply to every patient or product. Studies differ, and hyaluronic acid remains an option to discuss for selected patients.
Is high-dose PRP always better than conventional PRP?
No. Total platelet dose may matter, but composition, volume, preparation and the number of injections also count. ACP MAX is a preparation system, not a guarantee of better results. Read more about PRP / high-dose PRP.
Can an injection prevent a knee replacement?
This cannot be guaranteed. Injections aim to relieve symptoms. For severe limitations or advanced osteoarthritis, we also discuss other treatment pathways and orthopaedic assessment when appropriate.
Safety, preparation and aftercare
Report medication, blood thinners, diabetes, allergies, infections, earlier knee injections and planned surgery. Do not stop medication yourself. Discuss total costs and possible reimbursement beforehand.
Seek same-day medical advice for increasing severe pain, a hot or red and markedly swollen knee, fever or feeling unwell after an injection.
Practical information and aftercare
Scientific background
Guidelines differ. ESSKA supports selected PRP use; AAOS is more cautious about the strength of evidence. NICE and AAOS are critical of hyaluronic acid. Long-term Arthrosamid follow-up does not establish that it lasts longer than other options for everyone.
Sources and further information
- ESSKA-ORBIT (2024) · ESSKA-ICRS (2024)
- AAOS (2021) · NICE NG226 (2022)
- Hyaluronic acid: therapeutic trajectory (2011) · Repeated triamcinolone: randomised trial (2017)
- Arthrosamid: 3-year follow-up (2026) · Arthrosamid: 5-year follow-up (2026)
- Arthrosamid: instructions for use · Arthrosamid: treatment process · NHS: steroid injections
Updated: 14 October 2026.
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