Tell me about polyacrylamide hydrogel joint injections (Noltrex)

[x-halt-salute]

I’ve got a horse who has a heightened risk of adverse effects from steroid IA injections (almost killed her that way; don’t fancy doing it again if I can help it). She’s developed a joint issue that requires treatment, and one of the options that is on the table is Noltrex. It sounds promising in many ways, but I have zero firsthand observation of its use.

The scientific literature re: intra-articular polyacrylamide gel in horses is pretty sparse, and sample sizes are fairly small, and a search for forum posts on it hasn’t turned up much, so I’m also curious what others have experienced with it.

Has anyone used Noltrex (or another polyacrylamide gel product) it for milder OA (as opposed to last-hope type advanced joint pathologies)? How long ago was the initial treatment, and how have things gone since then? Anyone have any adverse effects (I realize that joint sepsis is a risk of any procedure that invades the joint capsule, but curious if anyone has seen other things that aren’t documented in the small-n literature)?

Thanks for any insights anyone here is able to share!

[TBKite]

I have used it once, but mine is one of those last- ditch cases with a goal of pasture- or maybe-possibly-hopefully-hacking-sound.

We’ve had no adverse effects, he was a bit more sore for a few days after but the joint was already very angry with advanced DJD.

The joint is less puffy and inflamed now, horse improved but still lame (was done about three years ago). I would be very interested in how a milder case would do, as mine was very end- stage.

[gnu]

Used it spring 2019 in upper carpal joint. Horse came off track 2018; had a few chips and small osteophytes. At surgery also found damage to radiocarpal bone cartilage. Once bandaging was ended post surgery, fluid accumulated in joint. Since noltrex injection, less fluid and not as firm. fyi horse was and is presently sound, No issues post injection.

[SolarFlare]

I used it in an ankle, very mild pre-arthritis (some inflammation but no loss of joint space on xray). Did the prescribed “rehab” of about a month, building back to work slowly. It lasted 15 months. Vet and I were very pleased with the results, and I’ll use it again.

[jawa]

According to my vet, it is great for ankles and such, not so great for hocks. He stated that there just wasn’t enough room in the hock joint to use the size needle needed to inject the gel.

[TBKite]

Agree with that, the gel is very thick. My very end- stage use was on an ankle.

The vet I used has since also done a knee. That horse was still last- ditch (did not respond to steroids sufficiently), but has been able to return to racing since getting the gel.

[joiedevie99]

A friend used it on a post-surgical fetlock fracture with joint involvement. Horse came sound enough for basic flatwork. She seemed pleased. My vet and I had a discussion about this very recently (and ultimately chose Pro-Stride), but she similarly said she’s mostly used it in last-ditch-effort situations and doesn’t have a great body of personal experience with it in more normal situations.

[SolarFlare]

@jawa

According to my vet, it is great for ankles and such, not so great for hocks. He stated that there just wasn’t enough room in the hock joint to use the size needle needed to inject the gel.

It was explained to me that it’s for use in motion joints. I asked about using it in the lower hocks and was told not to bother, but the room for the needle wasn’t mentioned. I’m pretty sure my vet said that he saw some reports (not sure if it was an actual study, or perhaps a presentation at a conference?) that it didn’t work as well for non-motion joints.

[x-halt-salute]

Thanks for the feedback, everyone. This is very helpful. I’ve got a lot of thinking to do …

”‹”‹”‹It’s between this or IRAP, and my vet seems to think this is the better option for my horse, even though the joint in question isn’t one of the super high motion ones. I’ve sent all the imaging along to the nearest big vet school for a second opinion type consult. Will be interesting to see what they say.

My horse is not visibly lame on the longe, but is 0.5/5 under saddle (I can feel it, vet can see it, most barnmates can’t see it) and 1-1.5/5 with flexion. But she’s uncharacteristically unhappy to work so I’m eager to get her feeling better… We’ve had some bad luck in the past that has left me second guessing some of the interventions I’ve opted for, so I guess I’ve grown a bit gunshy about whether treating a mild lameness can create bigger problems. It sounds like Noltrex doesn’t do any harm in the cases where it’s not very effective, but it’s hard to be confident about something that’s used so little!

[Laurierace]

I haven’t heard of that so can’t comment but what about just straight HA?

[x-halt-salute]

@Laurierace

I haven’t heard of that so can’t comment but what about just straight HA?

I don’t think the efficacy of exogenous HA is well enough established that it’s worth the risk of invading the joint capsule to inject HA alone. This article published a couple of years ago combines with my personal observations in giving me a fairly low opinion of HA as a standalone treatment: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804525/

[SolarFlare]

@Laurierace

I haven’t heard of that so can’t comment but what about just straight HA?

@x-halt-salute

I don’t think the efficacy of exogenous HA is well enough established that it’s worth the risk of invading the joint capsule to inject HA alone. This article published a couple of years ago combines with my personal observations in giving me a fairly low opinion of HA as a standalone treatment: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4804525/

Interestingly, in mine, his lower hocks respond beautifully to HA (we do once a year), however the ankle will only get 3-6 months. I say interestingly because the ankle isn’t even showing arthritis (I guess it would qualify as synovitis). Maybe because the ankle joint is a motion joint? Again, I got 15 months out of the Noltrex. It forms a thick cushioning layer that lasts longer as it adheres to the soft tissue, forming a sort of fake cartilage.

[x-halt-salute]

@SolarFlare

Interestingly, in mine, his lower hocks respond beautifully to HA (we do once a year), however the ankle will only get 3-6 months. I say interestingly because the ankle isn’t even showing arthritis (I guess it would qualify as synovitis). Maybe because the ankle joint is a motion joint? Again, I got 15 months out of the Noltrex. It forms a thick cushioning layer that lasts longer as it adheres to the soft tissue, forming a sort of fake cartilage.

Thanks for this.

By ankle, I assume you mean fetlock. I think you’re onto something w.r.t. high-motion vs. low-motion joints. I’m impressed that the response you get from HA in lower hocks lasts a full year!

Alas, I’m dealing with a slightly more complicated situation than typical lower hock OA (different joint and secondary to an acute injury in my horse’s case), which I suspect factors into my vet’s recommendation to look at Noltrex.

Anyway, thank you very much for sharing your experience. 15 months is a great result. I’m still waiting on a second opinion, but based on the shared experiences here am feeling a bit better about giving Noltrex a shot.

[SolarFlare]

@x-halt-salute

Thanks for this.

By ankle, I assume you mean fetlock. I think you’re onto something w.r.t. high-motion vs. low-motion joints. I’m impressed that the response you get from HA in lower hocks lasts a full year!

Alas, I’m dealing with a slightly more complicated situation than typical lower hock OA (different joint and secondary to an acute injury in my horse’s case), which I suspect factors into my vet’s recommendation to look at Noltrex.

Anyway, thank you very much for sharing your experience. 15 months is a great result. I’m still waiting on a second opinion, but based on the shared experiences here am feeling a bit better about giving Noltrex a shot.

Yes - fetlock. Vet and I refer to it as “that ankle” (as in, “hey vet, time to come out and do ‘that ankle’ again” )

We actually tried IA Adequan last year in the hocks, and I only got about 8 months out of it, so we went back to HA. I’m interested to see if this time, it lasts the year again, or if it’s just that the arthritis is worsening (so maybe it wasn’t because we used Adequan instead of HA).

ETA - he also gets a monthly shot of Ichon (like IM Adequan), and we’ve done the loading dose a couple times. It’s really made a difference and has allowed us to go from getting hocks done every 6 months to every 12.

I hope the Noltrex works out for you. My vet’s been using it on a number of motion joints and has been really happy with the results his clients are getting. He also works with racehorses, and I know he’s got one with a knee that was coming up sore after racing. They used the Noltrex, and even without the proper rehab it was much improved (though they did have to do a second shot fairly soon after). I think that horse was only given a few days off, then right back to it. The rehab period is to allow the gel to set up, so that the compression in the joint doesn’t squish it out. It’s a bit of a pain to take a month of slow work to get back so I try to plan for winter to do the Noltrex, but the results are worth it.

[Samantha37]

I just spoke with a vet who is recommending this treatment for one of my clients, and it was the first time I’ve heard of it and I’m totally fascinated. Of course, he said it doesn’t really work for hocks or other big joints, which is what my horse needs, but he said for smaller joints it is incredible.

I’m very interested reading these reviews

[Natalie]

I’m interested in this as well…it sounds like it could work for coffin joints in particular. Does anyone know what the pricing on it is?

[SolarFlare]

@Natalie

I’m interested in this as well…it sounds like it could work for coffin joints in particular. Does anyone know what the pricing on it is?

I think when I first looked into it (about two years ago), it was about $300-$350US. We ended up getting a distributor in Canada so I think it was about $350CAN when I used it. Pricing may have come down since then (I hope!). That was just for the Noltrex, not including call fee/injection fee/etc.

[Guyot]

We’ve put it in a couple of stifles. One horse has a very thin meniscus right stifle and this really helped him when joint injections were no longer working. He still is not back to 100% of his work load as we only injected in August and he was off for couple months prior to that. We are slowly building back up to full work load. So no lateral work or high collection.

We also tried this in another horse who has no real pathology in his stifles but gets very sore with increased collection. So far results are encouraging. Horse is more comfortable; even on his therapeutic hill works.

Have not used it in other joints but probably will going forward. It is slightly more costly then regular injections of cortisone and HA but not by a lot.

[WB_Mom]

I have used it in the front fetlock joint twice now. Originally had the fetlocks injected, then came back in a few weeks for the Noltrex. Very good results. After 17 months went back for another injection. Again very good results. It’s around $350.00 just for the injection. I have been very happy with the results and will continue to get them done anywhere between 12-18 months. The horse looks great and is sound. Now if the hocks would just get done fusing - HA!

[SporthorseFun]

I used it for my horse’s stifle after three months of rehab following OCD lesion surgery on a non-load bearing surface. Unfortunately, it did not make a difference. There was still pain, and the Equioxx created ulcers. It appears this horse needed more time to heal and a very conservative rehab program.