Polyacrylamide Hydrogel for stifle?

My mare has Cushings and so cannot have steroid injections. She had a ProStride treatment for her stifle a couple of months ago. It helped a little but she is still pretty lame under saddle. I know there are two versions of the Polyacrylamide Hydrogel products, Arthramid and Noltrex. I’d be interested in experiences with either, and in the stifle joint specifically. Vet is coming back in a couple weeks and we’ll need to decide whether to try the ProStride again, or something else.

Have you tried Estrone yet? For my tb with a sticky stifle it works better than direct joint injections.

I’m in a similar situation. My metabolic gelding’s stifle was injured in July 2022. He foundered after steroid treatments because we didn’t know he was metabolic at the time. When he finally stabilized from that, the injury was months old but he was still 2/5 lame on the stifle without being ridden. A week ago, we injected his stifle with 2 units of Arthramid. It’s too early to see results but I will try to report back in a few weeks.

I am VERY hopeful that it will help his injury. I am very impressed by the papers and case studies I have seen. It seems to be hugely superior to steroids and actually supports the joint and encourages proper movement and healing instead of just masking discomfort. It was our best option to heal the joint without surgery, which was not an option because the risk of another laminitic episode from anesthesia is too high.


I assume you mean some injury or arthritis, not just “sticky stifle”? If so, I’d go for it.

This was my assumption based on her description. I’ve seen “sticky stifles” helped with estrone. I think those were patellar tendon issues though, so the estrone was able to help the tendons specifically.

If it’s an injury or arthritis as I suspect, Arthramid can have some really impressive results. Not cheap but the horse can keep improving for 6-9 months after the injection and can keep benefitting from the injection for up to 2 years.

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I believe @TWH_Girl has done Noltrex and Arthramid for stifles.

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Yes! Unfortunately, stifle issues are all too common in my beloved TWH. My older guy is kept comfy but has issues that need tending to and the stifles are probably the most problematic for him. When he first had issues around 12 or so, he responded well to steroid/ha injections so we did those annually until a few years ago. His issues are R stifle OCD (never had surgery) and mild to moderate OA.

I tried Prostride 3-4 years ago but just never felt the WOW factor. I think it help marginally but then I ended up having his SI injected (he honestly probably shoulder have been retreated for the stifles). the vets always think it’s somethign else. But I know by he stands, walks, and picks up his feet that it’s his stifles. They finally believe me and don’t do flexions anymore…

The following two years, I have used Noltrex. We added a little bit of steroid the 2nd time we did it for inflammation. It takes about 3 weeks and then all of a sudden, my horse was moving really well- he felt strong, soft and motivated. The only issue I have truly had with Noltrex is it did not last as long as I had hoped for at all. I honestly had to retreat after about 4 mo which was very hard on my pocketbook and sort of the defeated the entire reason for using a pricier, supposedly longer lasting product up front.

I am currently causally searching for a horse…I was debating- do I inject my guy this year to keep him comfy so we can ride? He’s almost 21 so we do trails and mostly just bum around. But I DO like to canter. Will never buy a Walker who can’t lol. Anyhow, hubby said get him done- he’s a good boy and you don’t have another to ride. So my vet finally has Arthramid and I decided to try that instead of Noltrex. It’s only been just two weeks so I cannot speak to how long this will last. I rode him the other day and he was soft and offered a nice canter and gait. I am giving it a few more rides before I let my vet know but longevity will be a key for me.
I hope and pray for a longer response time from Arthramid. At some point, yes, my boy will have shoes pulled and stay on Equioxx and be retired :frowning: …until then, I work to keep him comfy and listen to him and we do what we can which is some days a lot, and other days not. He’s gonna be a tough one to let go of riding…he is a so sweet and such a joy.

One point on biologics that doesn’t get pointed out often- in older horses they have less anti-inflammatory [mediators or whatever it’s called] to reinject into them. That’s why often the response is lackluster compared to a younger horse with a more acute injury.

Good luck with your horse OP and keep us posted on how it goes :slight_smile:


I have a friend w a seasoned jumper w a bad stifle and they do Noltrex with some
Shockwave I believe. Good results

Edited because I was wrong!

Arthramid integrates with the joint in the first week. After 4-6 weeks, no further improvement is expected.

Always wondered about shockwave in stifles. Nice.

I’m not familiar with Estrone. Not sure what is meant by “sticky stifle” – my mare has arthritis, so her issues are with stiffness, discomfort with work etc. Equioxx helps, but not as much as needed. I find an interesting study, published in fall of 2022, on the 2.5% polyacrylamide hydrogel (I think that’s the Arthramid?). It seems to say that given proper technique, the product is safe, and can be effective to reduce stiffness and pain in the stifle. Quoting “full response to the treatment begins as early as 1 week post-injection and may, in rare cases, need a few weeks to a few months for a full response. . . . It has been stated that the effect of 2.5% PAAG on OA might occur mainly during the first month after treatment and lasts and increases progressively until 6 months, with a stabilization between 6 and 24 months.” A. Tnibar, “Intra-Articular 2.5% polyacrylamide hydrogel, a new concept in the medication of equine osteoarthritis: A review”, Journal of Equine Veterinary Science, October 2022.

My vet has some experience with PAAG, not sure if it’s the Noltrex or the Arthramid, but I’ll definitely be discussing this option with her. If I wind up trying it, I’ll update. Thanks for the feedback!

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Yeah absolutely recommend trying one of the PAAG treatments! Here is an article on sticky (aka locking) stifles: https://equusmagazine.com/horse-care/sticky-horse-stifles/

“sticky stifle” is a lesser symptom of UFP - upward fixation of the patella, aka locking stifle, and is about the patellar ligament.

Arthritis is a whole different ballgame, and is about the joint, not the ligament.