The treatment
A single hydrogel injection that cushions the joint.
The treatment uses a hydrogel that is 2.5% cross-linked polyacrylamide and 97.5% water. It is non-degradable and integrates with the synovial tissue lining the knee, cushioning the joint and reducing pain.
Source: Manufacturer instructions for use (IFU) and patient brochure.
The evidence
Pain improvement maintained out to five years
Across published studies, WOMAC pain improvement of at least nine points after a single injection has been maintained, with follow-up data extending to five years.
Source: Bliddal et al. 2024, Osteoarthritis & Cartilage 32(6):770–771; Bliddal et al. 2025 (5-year follow-up, WCO-IOF-ESCEO). Based on published clinical studies (Bliddal et al.); individual results vary.
There is no cure for osteoarthritis. Treatment may reduce or relieve knee pain, but symptoms may not improve and in some cases may worsen. Individual results vary.
Approvals
A regulated, established treatment
- Health Canada approved since 2024
- CE marked in Europe Class III medical device
- 220+ clinics in Europe routine clinical use
Source: Regulatory status as of 2026 (Health Canada approved 2024; CE marked; not FDA approved). Manufacturer data on file.
Inside the clinic
Where your treatment takes place
Procedure day
What the day looks like
- Step 01
Arrive
You arrive at the Thornhill clinic for your scheduled appointment. Plan not to drive yourself home that day.
- Step 02
Oral antibiotics, 1–2 hours before
You take prophylactic oral antibiotics as part of the Arthrosamid treatment protocol, which reduces infection risk.
- Step 03
Local anaesthetic
A local anaesthetic is administered to numb the injection site.
- Step 04
Ultrasound-guided injection
Arthrosamid is injected precisely into the joint under ultrasound guidance. The procedure itself takes only a few minutes.
- Step 05
Rest 20–30 minutes
You rest briefly so we can confirm you are comfortable before leaving.
- Step 06
Home the same day
You go home the same day with your rehab plan. Avoid driving on the day of the procedure.
Recovery
A gradual return, with a plan to follow
Some relief is possible within days. Most people notice gradual improvement from around ten days, with maximum benefit typically between four and twelve weeks. Avoid strenuous activity in the first weeks. You are given a structured rehabilitation plan to guide your return to activity, which you can follow with a physiotherapist or local provider near home. That keeps recovery convenient for patients travelling from out of town, and a free online rehabilitation programme is also available on the Arthrosamid website.
Source: Patient leaflet and consent form.
There is no cure for osteoarthritis. Treatment may reduce or relieve knee pain, but symptoms may not improve and in some cases may worsen. Individual results vary.
Side effects, honestly
What to expect, and the rare risks
The most common after-effects are temporary joint pain and a sensation of swelling, usually mild and lasting days to weeks. No serious side effects were reported in clinical trials. Rare risks include joint infection and allergic reaction; sterile technique and the prophylactic antibiotic protocol are used to reduce that risk.
Source: Bliddal 2021, J Orthop Res Ther; Overgaard 2019. Manufacturer data on file.
Peer-reviewed safety evidence: Neurotoxicity study (Frontiers, 2025)Systematic review (Medical Research Archives)
Who it isn’t for
Contraindications & cautions
Not suitable with
- A prior knee replacement or other foreign material in the knee
- Arthroscopy of the knee within the past six months
- An active infection or skin disease at the injection site
- Haemophilia or uncontrolled anticoagulation
- A previous non-absorbable injectable in the knee
Discuss carefully if you have
- Poorly controlled diabetes
- Autoimmune disorders
- Pregnancy
- Under 18 years of age
Source: IFU and consent form.
Common questions
What is the hydrogel made of?
It is 2.5% cross-linked polyacrylamide and 97.5% water. It is non-degradable and integrates with the synovial tissue lining the joint.
Does the injection hurt?
A local anaesthetic is used. The most common after-effects are temporary joint pain and a sensation of swelling, usually mild and lasting days to weeks.
When will I notice a difference?
Some relief may begin within days. Most people notice gradual improvement from around ten days, with maximum benefit typically between four and twelve weeks.
What are the risks?
No serious side effects were reported in clinical trials. Rare risks include joint infection and allergic reaction; sterile technique and prophylactic antibiotics are used to reduce this risk.
There is no cure for osteoarthritis. Treatment may reduce or relieve knee pain, but symptoms may not improve and in some cases may worsen. Individual results vary.
Book a consultation
Take the next step
A consultation reviews your diagnosis, confirms whether the treatment is suitable for you, and answers your questions. The consultation fee is included in the all-inclusive treatment price.
- Health Canada approved (2024)
- Physician-led care
- Consultation fee included
- 25 minutes from Toronto Pearson