Osteoarthritis is the most common form of arthritis affecting the knee joint. It is becoming more common in younger people. Treatment options include exercise, weight loss, medication, injections, and knee joint replacement. A new type of injection called an Arthrosamid gel shows more promise than other injections in reducing the pain of knee arthritis. So, what is Arthrosamid UK, and how effective is it in knee arthritis?    

Osteoarthritis

Osteoarthritis is a chronic condition commonly affecting the knee joint. It wears away the shock-absorbing cartilage of the joint’s surface, causing bone-on-bone rubbing. This bone contact leads to inflammation, stiffness, and joint pain. Pain from knee arthritis comes from inflammation produced by the joint rather than cartilage wear.  

Treatment options for osteoarthritis

The most effective treatments for knee osteoarthritis include exercise therapy and weight loss. Medications such as ibuprofen can also help. In addition, we use injections into the knee joint for more severe cases of knee arthritis. Common injections for knee arthritis include cortisone, hyaluronic acid, and PRP. Recently, a new type of injection called Arthrosamid offers people an effective alternative to currently available injection therapies. 

What is Arthrosamid UK?

Arthrosamid UK is a new hydrogel material with water molecules (97%) attached to a polyacrylamide backbone (3%). It is non-degradable, meaning the body can’t break it down. 

Doctors have used hydrogel as a bulking agent for medical problems, such as stress incontinence and face filler, for over 20 years. In joints, it has been used extensively in horses with arthritis since 2009. 

Over 10000 Arthrosmaid injections have been performed in Europe and the UK since its approval over ten years ago. 

How does Arthrosamid UK work? 

The synovium is a thin membrane lining the joint and contains synovial cells. These cells produce joint fluid to lubricate and keep the joint healthy.

When we inject hydrogel into the knee joint, it is taken up by the synovial cells and forms a new joint lining. This new lining reduces the knee’s inflammation, leading to less pain. The gel also produces cushioning and lubrication. 

A New Laboratory study supports Arthrosamid gel mechanism of action theory

A new study examined how Arthrosamid works in knee arthritis. Scientists performed biopsies of the knee after an Arthrosamid injection. They found that the gel was taken up by the cells lining the joint, also called the synovial cells. These cells made a new ‘pseudo’ joint lining. 

Evidence in Knee Osteoarthritis 

Firstly, two promising studies published about ten years ago showed that hydrogel injected in arthritis knees showed excellent results starting at four weeks and continuing until 26 weeks. Follow-up studies show this effect persists for up to 1 year or longer. 

Moreover, a randomised controlled trial between Arthrosamid and hyaluronic acid in people with knee arthritis showed similar improvements at one year. However, in younger (70 years) and slimmer patients, Arthosamid performed better than hyaluronic acid. 

Also, we had about an overall 73% positive response rate to Arthrosamid gel in this RCT. But this response is dependent on age:

  • <60 years: 94% 
  • <70%: 80% 
  • Over 70s: 63% 

Studies suggest that the pain-relieving effect starts at four weeks and is maximal at about 12 weeks. However, one recent study from Turkey indicates that the pain-free effect may take up to six months to start. Sometimes, pain-relieving effects can begin within two weeks. 

Also, the average improvement in pain and function is 20-25%, starting at twelve weeks. Moreover, this positive effect lasts for three years and perhaps beyond. We await further long-term data to see if this effect lasts longer. 

A new study suggests that Arthrosamid works better than hyaluronic acid in a swollen knee.

A new study comparing Arthrosamid to Synvisc-1 (hyaluronic acid) found that patients with swelling in the knee joint responded better to Arthrosamid at six months. So, if you have a swollen knee, consider Arthrosamid rather than Synvisc-1 to relieve pain and improve function in knee arthritis.  

graph showing effect of Arthrosamid on knee pain

How do we deliver Arthrosamid injection? 

We inject this hydrogel directly into the knee joint. We strongly suggest that you have this procedure with ultrasound guidance. The hydrogel must be delivered accurately in the joint rather than outside it. Without ultrasound guidance, the accuracy of a knee injection is only 50-80%. Therefore, one in three to five injections without guidance does not get into the joint.

Generally, your doctor will give you a local anaesthetic in the skin. Then, your doctor will insert a needle with ultrasound guidance into the knee joint. The hydrogel is injected directly into the joint through the needle. Your doctor must inject it with a sterile technique. Please take a look at the video below of Dr Masci using ultrasound guidance to inject it into a person’s knee joint. 

What should you expect immediately after the procedure?    

Following the procedure, we will observe you for 15 minutes. You might feel a tightness or mild pain once the local anaesthetic wears off. So, it would be best to continue with your regular medications and painkillers.

Receiving Arthrosamid may feel like a different sensation from other treatments that you have previously experienced, as it is more viscous than other injectables. 

Injection side effects 

Generally, this implant is well-tolerated.

The most common side effect is pain and discomfort at the injection site. Although relatively mild, symptoms can sometimes last 2-4 weeks. The knee joint may also feel full or distended, and swelling of the Baker’s cyst may occur.

Rare side effects include allergic reactions and infection. However, the rate of serious adverse effects is very low. The overall safety of Arthrosamid has been established over 20 years in different body parts. 

How does Arthrosamid UK differ from other injections?

Arthrosamid differs from other injects, such as hyaluronic acid, PRP, or stem cells. The hydrogel is non-absorbable, which lasts longer in the joint, providing lubrication. Conversely, the body quickly degrades hyaluronic acid and PRP, so the effect is limited and less potent. 

Arthrosamid injection UK cost 

Dr Masci performs this injection for £2300. He performs this procedure with ultrasound guidance to improve accuracy. He has over fifteen years of experience in ultrasound-guided procedures and teaches doctors and physiotherapists how to inject with ultrasound. 

Other frequently asked questions: 

When can you return to sport about an Arthrosamid gel injection? 

Generally, we suggest you rest your knee from exercise for about a week after the hydrogel injection. Short-term rest reduces the chances of a flare or swelling. The onset of the pain-relieving effect is four weeks, although it may take longer. 

An example of a return to running after an injection:

On Day 1 post-injection: complete rest, ice and oral ibuprofen for pain

Day 2 post-injection: Restart upper body weights, swim without kicking and continue ice and ibuprofen for a flare.

On Day 3-5 post-injection: Continue upper body weight, swimming with kicking, light cycling

Day 6-7 post-injection: Continue upper body weights, swimming, light cycling, and start lower body weights at 50% of the usual intensity. 

Day 8 post-injection: Start running depending on pain. 

Is an Arthrosamid gel a type of hyaluronic acid? 

No. Hyaluronic acid is found in tendons, ligaments, and joints, so the body quickly breaks it down. On the other hand, Arthrosamid hydrogel is non-degradable, meaning it lasts longer in the knee joint.

Are there any contraindications to using Arthrosamid gel? 

Generally, we should not inject Arthrosamid if:

  • If the knee has active skin or joint infection
  • You have been injected with cortisone, hyaluronic acid, or PRP. It would be best to wait until the body has absorbed the cortisone or hyaluronic acid (the exact time varies depending on the drug). 
  • The knee contains metal for a replacement
  • You have had a knee arthroscopy within six months
  • You have infections in other joints 
  • You have an inflammatory arthritis, such as psoriatic arthritis.
  • Minors (less than 18 years) or pregnant women 

Are there any studies comparing Arthrosamid gel to PRP? 

No. However, one study compares hydrogel to Synvisc-1, a type of hyaluronic acid. In this study, both Arthrosamid and Synvic-1 performed equally at 12 months. However, the data at three years shows that the positive effect of Arthrosamid continues. 

Can you have Arthrosamid gel injected without imaging?  

picture of arthroasmid injected into knee joint with ultrasound-guidance

Yes, but we don’t recommend it. We know that using ultrasound improves the accuracy of a knee joint injection. For example, studies suggest knee injections without ultrasound are only 60-80% accurate compared to ultrasound with 100% accuracy. So, if you’re thinking about Arthrosamid, you should ensure you have it injected with ultrasound. 

Why are prophylactic antibiotics recommended?   

As Arthrosamid is non-degradable, you must have antibiotics. A high concentration of an antibiotic at the time of the injection reduces infections. So far, there have been no documented infection cases from an Arthrosamid injection.

How long does Arthrosamid UK take to work? 

According to company data, pain relief usually starts at four weeks. However, the maximal effect can take up to six months. In one recent study from Turkey, positive effects may take up to six months to start. 

How much does Arthrosamid reduce pain and improve knee function? 

Arthrosamid improves pain and function by 20% on average. This effect starts at six to twelve weeks and continues for at least three years. 

How long does Arthrosamid last? 

Studies suggest Arthorosamid lasts for at least a year. Recent evidence suggests this positive effect has been maintained for three years. We await longer-term studies over five years to establish the extent of this effect. 

The makers of Arthrosamid have committed to obtaining more data to learn who responds best to Arthrosamid. 

Can Arthrosamid be used for arthritis in other joints? 

Practitioners have started using Arthrosamid for hip, ankle, and shoulder arthritis. However, this drug has not been approved for use in other joints, so we do not recommend it.

Can we use Arthrosamid for inflammatory arthritis such as psoriatic or rheumatoid arthritis?

While Arthrosamid may work well in inflammatory arthritis, it has not been approved.

When will Arthrosamid UK be available in the USA?

Contura has applied for FDA approval and is well into the process of getting Arthrosamid approved in the States. They have also applied to regulatory bodies in Canada and Australia. It is hard to predict when the approval process will be completed. 

Is Arthrosamid UK available on the NHS? 

No. However, we are conducting studies at various NHS trusts throughout the UK. You can contact your local trust to find out more. 

Can you have a knee replacement after an Arthrosamid injection?

Yes. Unlike other injects, such as cortisone, there have been no concerns about having surgery after Arthrosamid. 

Do higher-risk patients, such as diabetes, have a different response? 

Perhaps. The effectiveness of Arthrosamid drops by about 10% compared to non-diabetic patients. However, having diabetes is not a contraindication. 

Can people with a history of active cancer have Arthrosamid? 

Yes. Arthrosamid is not a contraindication with active cancer patients, unlike other injectables such as PRP. 

We know that some patients don’t respond to Arthrosamid. Can some patients get worse after Arthrosamid? 

Yes. While the majority of patients improve with Arthrosamid, some don’t, and some can get worse. Recent data shows that about 6-20% of patients can have worse scores after an Arthrosamid injection. This data is not unlike other injects such as hyaluronic acid, PRP or stem cells. Worsening scores may be due to deteriorating arthritis rather than the Arthrosamid. 

Can I receive treatment in both my knees? 

Yes. However, as a general rule, we suggest separating the injections by at least a week and not having them done at the same consultation. 

Final word from Sportdoctorlondon about Arthrosamid UK

Could Arthosamid be a game changer for people with intractable knee arthritis? Potentially yes. We suggest considering Arthosamid if you’ve tried exercise, weight loss, and other injects like Durolane or PRP. You need to understand that not all patients improve with Arthrosamid, 

Dr Masci offers an Arthrosamid injection for £2300. He also treats patients from the USA and Canada. If you are interested in Arthrosamid, please contact his dedicated team for further information.  

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