Knee Injection Comparison
Arthrosamid® vs
Steroid Injection
Corticosteroid injections give short-term symptom relief; Arthrosamid® is a long-acting hydrogel cushion. Here is the honest comparison from London Cartilage Clinic, including when each is the right choice.
Reviewed byProf Paul Lee MBBch, FRCS (Tr & Orth), PhDLast reviewed 1 May 2026Quick Answer
Corticosteroid injections reduce inflammation and give weeks to a few months of symptom relief; they are useful for short-term flare control. Arthrosamid® is a non-resorbable hydrogel cushion with published outcome data showing on average two to three yearsof relief from a single injection. Steroid injections remain useful for short-term symptom control; Arthrosamid® is generally the better answer where the question is “can you give me a year or more without surgery?”
The Headline Difference
Arthrosamid® vs Steroid Injection — the key difference
The core difference is duration and mechanism. Steroid injections work biologically by damping inflammation — useful in the short term, but the effect fades over weeks to a few months. Arthrosamid® works mechanically by cushioning the joint long-term. These are different tools for different goals: steroid for short-term flares, Arthrosamid® for sustained symptom control.
Mechanism of Action
How each treatment works
Arthrosamid® is a polyacrylamide hydrogel injected into the knee joint under ultrasound guidance. The gel integrates into the synovial membrane, acting as a long-term cushion. It is not absorbed, not metabolised and not regenerative.
Mechanism is mechanical — physical cushioning and lubrication.
Corticosteroid injections deliver a potent anti-inflammatory (typically methylprednisolone or triamcinolone) directly into the joint. The injection rapidly damps the inflammatory response and the symptoms it produces — pain, swelling and stiffness.
The drug is gradually metabolised over weeks to months, after which the effect tapers off.
How Long Results May Last
Duration and number of injections
2 to 3 years
Weeks to months
Repeated steroid injections in the same joint over time carry cumulative concerns about cartilage and tendon health — this is one reason longer-acting alternatives are considered for patients needing ongoing symptom control.
Treatment Course
Number of injections
One injection is the standard treatment course in suitable patients. Most cases are treated with a single box per joint, delivered as an outpatient appointment.
A steroid injection can be repeated, but most UK practice limits repeat injections in the same joint to two to four per year, and considers alternative approaches if a patient is relying on repeat steroid as their ongoing management.
Safety and Infection
Safety considerations
Both treatments are delivered under ultrasound guidance at London Cartilage Clinic. The most serious shared risk is joint infection, which is rare. Beyond infection, each treatment has its own risk profile.
Corticosteroid injections carry small risks of post-injection flare in the days after the injection, fat-pad atrophy at the injection site, transient blood-sugar rise (relevant for diabetic patients), and concerns about cumulative cartilage and tendon effects from repeated use in the same joint.
Arthrosamid® is a permanent hydrogel, so a late infection is harder to manage than for steroid. This is why we use routine IV antibiotic cover for Arthrosamid® specifically. See Arthrosamid® infection risk and prevention and Arthrosamid® side effects and safety.
Patient Selection
Who each treatment may suit
Steroid injections suit patients with short-term flares of knee osteoarthritis, those who need symptom relief ahead of a specific event (a planned holiday, a wedding, a return to activity), and those for whom a longer-acting injection is not appropriate.
Arthrosamid® tends to suit patients with established osteoarthritis who want longer duration from a single injection, and who are looking to delay more invasive treatment. Neither treatment is a substitute for knee replacement where replacement is clinically appropriate. See who is suitable for Arthrosamid?.
Cost and Value
What each treatment costs
At London Cartilage Clinic, Arthrosamid® costs from £3,000 for one box, inclusive of consultation, ultrasound, the product, the fifteen-step injection protocol and the six-week follow-up. See the Arthrosamid® cost guide for full pricing.
Steroid injections are significantly cheaper per dose. Where short-term symptom control is the genuine goal, steroid is the more cost-effective option. Where ongoing relief is needed and a patient is on a path of repeating steroid every few months, the total spend over two to three years can approach or exceed a single Arthrosamid® treatment — without the cumulative steroid concerns.
Our Honest Take
When we may recommend each
You have established knee osteoarthritis with mild-to-moderate cartilage wear.
You want longer-acting symptom control from a single injection rather than repeating steroid every few months.
You want to delay more invasive surgery when appropriate, with realistic expectations and willingness to accept the safety protocol.
Short-term flare control for symptomatic knee osteoarthritis.
Symptom relief ahead of a specific event (a planned trip, a procedure, return to a specific activity).
As a diagnostic tool, where the response to a single steroid injection helps clarify the source of pain before committing to a longer-acting option.
When Each Is The Wrong Answer
When we would not recommend each
End-stage bone-on-bone arthritis where Arthrosamid® is unlikely to deliver meaningful benefit.
Active infection or unwillingness to accept the conservative safety protocol.
Unrealistic expectation of cure, regeneration or guaranteed permanent relief.
Patients already on a pattern of repeating steroid every few months — a longer-acting option is usually the better answer.
Poorly controlled diabetes, where the blood-sugar effect is a meaningful concern.
Where prior steroid injections have not delivered useful benefit, repeating is unlikely to be the right next step.
The Bottom Line
In summary
Steroid injection and Arthrosamid® are tools for different jobs. Steroid is for short-term flare control; Arthrosamid® is for sustained symptom relief from a single injection. Where a patient is on a pattern of repeating steroid every few months, Arthrosamid® is often the better answer in suitable cases. The right choice for any individual is decided at consultation with imaging review.
Arthrosamid® vs Steroid Injection
Frequently asked questions
Is Arthrosamid® better than a cortisone injection?
For sustained symptom relief from a single injection, yes — Arthrosamid® gives multi-year relief on average versus weeks to months for steroid. For short-term flare control, steroid remains the more appropriate and cheaper option. They are tools for different jobs.
Can I have Arthrosamid® after a steroid injection?
Yes. Prior steroid is not a contraindication to Arthrosamid®. We typically allow time between steroid and Arthrosamid® to let the steroid effect taper, so the response to Arthrosamid® can be properly assessed. We will discuss timing at consultation.
How many steroid injections can I have in the same knee?
Most UK practice limits repeat steroid injections in the same joint to two to four per year, and considers alternative approaches if a patient is relying on repeat steroid as their ongoing management. Cumulative cartilage and tendon concerns are part of the reason.
Is steroid safer than Arthrosamid®?
Both have a favourable safety profile when delivered correctly. Steroid carries small risks specific to corticosteroids (post-injection flare, fat-pad atrophy, blood-sugar rise, cumulative concerns with repeated use). Arthrosamid® is a permanent hydrogel, so infection management is more complex if it does occur — which is why we use routine IV antibiotic cover for Arthrosamid® specifically.
Are steroid injections available on the NHS?
Yes, steroid injections for knee osteoarthritis are part of standard NHS care pathways. Arthrosamid® is not routinely funded by the NHS. See the Arthrosamid® funding and insurance page for detail.
Book an Arthrosamid® Assessment – London
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Learn More about Arthrosamid
Deep dive into our clinical resources and patient guides.
Cost in the UK
Arthrosamid® cost in the UK from £3,000, what is included and why prices vary.
NHS & Insurance
Is Arthrosamid® available on the NHS or private insurance?
Suitability
Who is suitable for Arthrosamid® — and who may need caution.
Clinical Evidence
Real-world outcome data and what the evidence means for patients.
Side Effects & Safety
Arthrosamid® side effects, risks, complications and clinical context.
Infection Risk
Arthrosamid® infection risk, prevention protocol and IV antibiotic policy.
In London
Private Arthrosamid® treatment at our Harley Street clinic.
Self-Assessment
Eight-question Arthrosamid® suitability self-assessment tool.
Full FAQ
Arthrosamid® patient FAQ across cost, suitability, safety and comparisons.
vs Hyaluronic Acid
Arthrosamid® compared to hyaluronic acid injections.
vs PRP
Arthrosamid® compared to PRP for knee osteoarthritis.
vs Steroid Injection
Arthrosamid® compared to corticosteroid injection.
vs Knee Replacement
Where Arthrosamid® may help delay surgery — and where it cannot.
Arthrosamid® Injection
Comprehensive Overview
Arthrosamid® is a registered trademark of Contura A/S. London Cartilage Clinic is not affiliated with or endorsed by Contura A/S.