The short answer right now

Right now, Arthrosamid does not look like a routine NHS treatment for knee osteoarthritis. The clearest NHS-linked public source is the Health Research Authority study summary, which says that in that NHS study pathway only steroid injections were available before surgery, while Arthrosamid was being investigated through research; recruitment has since closed. That is not the same as saying no NHS patient can receive it anywhere in the UK, because local pathways can vary, but a standard NHS rollout is not publicly established.

NICE has also considered Arthrosamid for symptomatic knee osteoarthritis and recorded it as “not selected” for Health Technology Evaluation guidance because the evidence was judged insufficient. By contrast, UK private access is publicly visible through providers such as Nuffield Health and Imperial Private Healthcare. In practical terms, patients who cannot access it through a local NHS or research-led pathway may find that private care is the clearer publicly visible route in 2025.

Why NHS access still looks limited

For most NHS patients in 2025, the key point is not whether Arthrosamid can exist in an NHS setting, but whether there is a routine route to it. The clearest public NHS-linked signal is the Health Research Authority summary for an NHS study: in that pathway, Arthrosamid was being investigated through research, while steroid injections were the only intra-articular option available on the NHS before surgery. That study has now closed recruitment, so it does not function as an open treatment route.

The other practical hurdle sits with NICE. NICE did look at Arthrosamid for symptomatic knee osteoarthritis, but its project page records the technology as “not selected” for Health Technology Evaluation guidance because the evidence was judged “insufficient”. That does not show the injection never helps; it shows the published evidence has not yet been strong enough to push the treatment into the kind of national evaluation that often supports wider NHS uptake. For someone asking about access now, the public picture is still of limited, local or research-led availability rather than a clearly established routine NHS offer.

What the evidence actually shows

For anyone weighing up private treatment, the most useful published signal is a 52-week open-label study of a single 6 mL ultrasound-guided Arthrosamid injection in 49 people with knee osteoarthritis. Arthrosamid is a polyacrylamide hydrogel used to try to reduce symptoms; this is about pain and function, not cartilage repair. In that study, 46 participants completed 52 weeks, WOMAC pain scores improved by 17.7 points, and 62.2% met the OMERACT-OARSI responder definition after one injection. In the later follow-up window, from week 26 to week 52, 8 adverse events were reported in 5 people, including 1 serious cerebrovascular accident, but none of the new events were judged device related.

Those numbers are encouraging because they suggest some patients may get meaningful symptom relief for at least a year from a one-off injection. The limit is the study design: open-label means there was no blinded placebo or active comparator, so expectation effects and other biases are harder to rule out than in a stronger randomised trial. More research did appear in 2024 and 2025, including work linked to a randomised Arthrosamid-versus-Synvisc-One trial, which suggests the evidence base is still moving forward. Even so, the clearest detailed evidence retrieved here remains promising but still limited for broad national decision-making.

What self pay changes

Across the UK, the clearest thing self-pay changes is whether access depends on finding an NHS route first. Public provider pages show Arthrosamid available privately through groups such as Nuffield Health and Imperial Private Healthcare, so access does not depend on local NHS availability. For someone trying to avoid uncertainty around NHS access, that can make a private injection a practical, minimally invasive option rather than a theoretical one.

The more useful takeaway is that paying privately does not dramatically widen who the treatment suits. Nuffield describes Arthrosamid for mild-to-moderate knee osteoarthritis, and says it is not used for inflammatory arthritis or for severe “bone-on-bone” arthritis. In other words, the private pathway mainly helps a fairly defined middle group: knees painful enough to limit walking, stairs or exercise, but not so advanced that an injection is unlikely to be the best answer.

That leaves a straightforward trade-off. Self-pay may bring earlier treatment and simpler logistics, but it also means paying out of pocket for a treatment whose public evidence base is still less settled than many people assume in NHS and NICE terms. Nuffield also states that, in severe disease, knee replacement is a more effective treatment than an injection-based approach. So the main private advantage is timing and convenience; the main limit is that it does not remove the need for careful selection, or make Arthrosamid the right option for end-stage arthritis.

How to decide if it is worth pursuing

Worth pursuing depends less on the product name than on the stage of the knee problem. Arthrosamid may be a reasonable discussion point in someone with persistent knee osteoarthritis symptoms who wants to delay surgery and understands that the published signal is promising rather than definitive: in a 52-week open-label study, 62.2% of patients were responders after a single injection. That is encouraging, but it is not a guarantee of lasting benefit for every knee.

More caution makes sense when the joint is clearly severe or “bone-on-bone”, or when inflammatory arthritis is part of the picture. Nuffield describes Arthrosamid for mild-to-moderate knee osteoarthritis, not inflammatory arthritis, and says knee replacement is more effective in severe disease. The practical comparison with other non-surgical options is symptom relief, likely durability, self-pay cost and, above all, whether the knee actually fits the treatment. The key decision is not where to book first, but whether a proper assessment supports any injection at all.

1. [1] Intra-articular Arthrosamid® injection for knee osteoarthritis: A synovial fluid biomarker study. (2025). https://doi.org/10.1016/j.joca.2025.02.214 https://doi.org/10.1016/j.joca.2025.02.214