If you've spent any time researching knee arthritis treatments lately, you may have come across a name that keeps popping up: Arthrosamid. The idea of a single injection that could ease knee arthritis pain for years at a time is a compelling one. Here's what we know about this emerging treatment, how it works, and where things currently stand with FDA approval in the United States.
What Is Arthrosamid?
Arthrosamid is an injectable hydrogel developed by Contura International, a Danish medical technology company. The formulation is simple on paper: about 97.5% purified water and 2.5% cross-linked polyacrylamide, a soft, biocompatible gel. Once injected into the knee joint, the hydrogel doesn't dissolve or break down the way many other injections do. Instead, it integrates into the synovial membrane — the thin tissue lining the joint capsule — where it acts as a kind of cushioning scaffold.
This is a meaningfully different mechanism than the injections most patients are already familiar with. Cortisone injections work by calming inflammation for a period of weeks. Hyaluronic acid ("gel") injections add lubrication to the joint fluid, but the body gradually absorbs them, so relief tends to fade over months. Arthrosamid, by contrast, is designed to remain in place indefinitely, physically thickening and supporting the joint lining rather than simply coating or lubricating it.
What Does the Research Show?
Arthrosamid has been used in Europe since 2021 and has since been approved in the UK, Australia, and Canada. Clinical studies and case series published over the past several years have generally reported meaningful improvements in patient-reported pain, stiffness, and physical function scores, with benefits documented anywhere from six months out to two or three years following a single injection in many patients.
The largest head-to-head comparison to date, the ROSA trial, compared Arthrosamid against a leading hyaluronic acid product in nearly 240 patients. At one year, Arthrosamid performed comparably to hyaluronic acid on pain outcomes, though the study also noted a higher rate of injection-related side effects (such as temporary swelling or discomfort) with Arthrosamid. As with any newer treatment, the body of long-term safety and effectiveness data is still growing, and it's smaller than what exists for treatments that have been in use for 20-plus years, like hyaluronic acid.
Where Does Arthrosamid Stand With the FDA?
Arthrosamid is not yet FDA-approved and is not currently available for use in the United States. It remains classified as an investigational product here. Contura International is conducting a pivotal U.S. clinical trial required for a Premarket Approval (PMA) submission, and results are anticipated over the next couple of years. If that trial is successful, a realistic estimate for U.S. availability is somewhere in the 2027–2029 range, though FDA timelines are difficult to predict with certainty and there is no guaranteed approval date.
In the meantime, Arthrosamid cannot legally be administered at any clinic in the U.S. outside of an approved clinical trial.
Who Might Eventually Be a Candidate?
Based on how the treatment has been used internationally, Arthrosamid is generally considered for patients with mild to moderate knee osteoarthritis whose symptoms haven't fully responded to conservative measures. It is not intended for rheumatoid or other inflammatory forms of arthritis, and it tends to be less effective in patients with severe, advanced arthritis — for whom surgical options such as knee replacement typically offer more reliable, lasting relief.
What We Recommend for Patients Right Now
We understand the appeal of a treatment that promises years of relief from one injection, and we're watching Arthrosamid's progress through the FDA process closely. In the meantime, our KneeRejuven8™ program already offers several proven, currently available options that follow a similar philosophy of restoring function and delaying more invasive interventions, including:
- Hyaluronic acid (gel) injections for joint lubrication and relief
- Platelet-Rich Plasma (PRP) and other orthobiologic therapies to support the joint's healing environment
- Class IV laser therapy to reduce inflammation and pain non-invasively
- Physical therapy and targeted bracing to improve mechanics and reduce joint stress
- Medically guided weight loss, which meaningfully reduces the mechanical load on the knees
If you've been managing knee arthritis and are wondering what your best options are today, we'd be glad to walk through where you stand and build a plan that fits your goals — without waiting on a treatment that isn't available yet.
Frequently Asked Questions
- Is Arthrosamid available in the U.S. right now?
No. As of 2026, Arthrosamid is not FDA-approved and cannot be legally administered at U.S. clinics outside of a clinical trial. - Where is Arthrosamid currently approved?
It is approved for use in the European Union, the United Kingdom, Australia, and Canada. - How is Arthrosamid different from a cortisone or gel injection?
Cortisone reduces inflammation temporarily, and gel (hyaluronic acid) injections add lubrication that the body slowly absorbs. Arthrosamid is designed to remain permanently in the joint lining, offering longer-lasting mechanical support. - Is Arthrosamid a cure for arthritis?
No. Like other injection-based treatments, it manages symptoms — pain, stiffness, and function — rather than reversing the underlying joint damage. - When might Arthrosamid be approved in the U.S.?
There's no confirmed date. A U.S. clinical trial is currently underway, and if it's successful, approval could realistically come sometime between 2027 and 2029. - What should I do about my knee pain in the meantime?
Schedule an evaluation with us. We offer a full range of proven, currently available treatments — from injections to physical therapy to surgical options — tailored to your specific stage of arthritis.
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