Arthrosamid for Knee Osteoarthritis
A non-biodegradable hydrogel injection used in selected knee osteoarthritis cases to improve joint cushioning and stability.
What Arthrosamid is
Arthrosamid is an injectable implant made of 2.5% cross-linked polyacrylamide hydrogel and 97.5% water. It is designed specifically for knee osteoarthritis.
In plain English
Arthrosamid is not a steroid, not PRP, and not standard hyaluronic acid. It is a longer-acting hydrogel implant intended to become part of the synovial tissue environment of the knee.
How Arthrosamid works
The current understanding is that Arthrosamid integrates into the synovial tissue, where it may improve tissue elasticity and cushioning while helping reduce the mechanical and inflammatory burden associated with knee osteoarthritis. The hydrogel remains structurally stable and is intended to continue functioning over time rather than being rapidly resorbed.
In practical terms
Improving the biomechanical environment of the joint lining
Reducing pain and stiffness in selected patients
Improving movement tolerance and function
Offering a longer-acting non-surgical option in an appropriate knee OA pathway
Important note
Arthrosamid is not a cartilage-regrowth treatment. It is best understood as a long-acting hydrogel implant for symptom and function improvement in carefully selected knee OA patients.
What the data suggests
Published and emerging data suggest that a single Arthrosamid injection can be well tolerated and can produce clinically meaningful improvements in pain and function for selected knee OA patients, with benefits extending well beyond the immediate post-injection period.
That said, the right patient selection remains central. Not every arthritic knee is an Arthrosamid knee.
Who Arthrosamid may suit
Arthrosamid may be appropriate in selected patients with:
Symptomatic knee osteoarthritis
Persistent pain and stiffness despite good conservative care
A desire to delay or avoid surgery where appropriate
A need for a longer-acting non-surgical option within a broader joint preservation strategy
It may be particularly attractive in patients who have plateaued with rehabilitation alone, are looking for a non-steroid approach, or want more durable symptom support than standard short-term injectables may offer.
What Arthrosamid can and cannot do
What Arthrosamid may do
Reduce pain in selected knee OA cases
Improve function and movement tolerance
Provide durable symptom support in a single-injection format
Fit into a broader non-surgical joint preservation strategy
What Arthrosamid cannot do
Reverse advanced structural collapse
Regrow cartilage
Eliminate the need for strength, movement and load management
Work for every arthritic knee
Safety and aftercare basics
Arthrosamid should be viewed as part of a longer-term joint preservation strategy, not a one-off mechanical fix.
Common short-term effects
Injection-site soreness
Temporary swelling or fullness
Transient flare in symptoms
Less common risks
Infection
Inflammatory reaction
Limited or no benefit
Prolonged irritation
Basic aftercare principles
Follow specific advice after injection, reintroduce loading progressively, do not judge the final outcome too early, and keep rehabilitation aligned to symptoms and confidence.
Typical timeline
First few days: Soreness, fullness or stiffness can occur.
First few weeks: Symptoms may fluctuate as the joint settles.
6–12 weeks: Often the period where clearer functional benefit is judged.
Months ahead: Benefits may continue as the patient progresses with strength, mobility and loading.
Frequently asked questions
Is Arthrosamid the same as hyaluronic acid?
No. Arthrosamid is a polyacrylamide hydrogel implant. HA is a viscosupplement that affects lubrication and the joint environment differently.
Is Arthrosamid suitable for all knee arthritis?
No. Suitability depends on the stage of OA, imaging findings, symptoms, and the broader treatment pathway.
How long does Arthrosamid last?
The intention is for durable benefit, but individual results vary.
Can I still do rehab afterwards?
Yes — and you should. Rehabilitation remains central to getting the best outcome.