And, to be honest, many times I’m not really sure what to say.
Really, when it comes to joint injections, there are two sort of different conditions that usually get treated. One is acute (acute = happened recently) arthritis (joint inflammation), you know, the kind you get when you mildly sprain your ankle or twist your knee (without doing any other kind of damage to ligaments and such).
Osteoarthritis is a different kettle of fish. Osteoarthritis involves bone (the “osteo-” part), and it’s generally chronic, that is, it’s a problem that’s been developing over a period of time. Without getting into all of the anatomy and such, the fundamental problem with osteoarthritis – and please keep this in mind – is you can’t cure it. And that’s a problem.
NOTE: In medicine, the number 1 ideal thing to do with any problem is to be able to help cure it. Get rid of it. Forever. If the problem is gone, the clinical signs (of which limping is the big one) go away. And everyone is happy.
With osteoarthritis, that “cure” option isn’t available. That means that nothing works. And it also means that people will try just about anything
NOTE NUMBER TWO: Here’s another Ramey Rule. The more treatments that there are for a particular condition, the less likely it is that any one of them really does much. If there’s a likely cure for a condition, everybody knows about it, and uses it. If there are dozens of treatments, it’s likely that none of them are really effective. And with osteoarthritis, well, there are magnets, and supplements, and special shoeing, and injections in the muscle, and injections in the vein, and liniments, and electrical stimulators, and, stem cells, and platelet rich plasma, and IRAP®, and I could keep going but I think you get my point. At best they might give some temporary relief, but they are certainly not going to cure the problem.
Oh, and joint injections – the subject of this article.
In February 2015, a study came out looking at how long you can expect an effect from joint injections. And it’s absolutely fascinating. So here goes.
This study was a real group effort. It involved 80 horses owned by clients – this wasn’t an experimental study, which, in my opinion, makes it especially interesting – and 13 veterinary clinics participated in the study. The group looked at how well one commonly used steroid, triamcinolone (TA), worked, compared to TA + HA (if you didn’t know, it’s almost mandatory to use abbreviations when you’re writing a scientific paper). The investigators kept track of lameness and joint swelling, and they checked with owners and referring veterinarians all the way out to three months after the horses were injected. And what they looked for was the clinical success rate, that is, they wanted to see how well the treatments worked (and they did all sorts of complicated statistical analysis, too, which is one of those things that’s very important, but almost mind-numbing if you’re not into it).
Oh, I almost forgot. You can CLICK HERE to read the whole study.
It’s not the results of this study are completely unexpected. A study done on 51 horses with osteoarthritis of the lower joints of the hock found that 58% of the horses improved initially, but that 90% of them had relapsed by about 56 days later (CLICK HERE to read it). HA alone certainly seems not to do the trick – a study of injections into the joint of the foot (the coffin joint, so named because, according to an 18th century text, it is contained within the hoof “as if within a coffin”) found that only 30% responded to injections that only contained HA (CLICK HERE).
Was this a perfect study? In a word, “No,” but to be honest, you can find faults with a lot of studies. However, the weaknesses of the study are at least partially overcome by the fact that 13 different clinics were involved (which overcomes problems that occur when only one person is looking at a study), and that 80 horses were used (which, compared to many horse studies, is a pretty good number). Of course, it would have been nice to see how things were going 6 or 12 months down the road, but if only half of the horses were better at 3 months, you wouldn’t expect the number to increase as time went by.
So, what’s to be made of all this? Well, it’s sort of a reality check. Here’s what I take away from it.
- Even though it makes some theoretical sense to use the drugs together, the TA + HA horses actually didn’t fare as well as the TA only horses when they were checked three weeks after injection.
- Nobody really knows why the combination didn’t appear to work as well.
- At three months, only half the horses were back to their previous level of work, even though the initial response was actually pretty remarkable (although there could have been other reasons for that).
- Corticosteroids in the joint are potent anti-inflammatory agents, but their effects don’t last all that long (three months or less).
- There doesn’t seem to be much reason to add the expense of HA to a horse’s joint when a horse is being treated for osteoarthritis.
- The older a horse is, the less likely it’s going to respond to treatment. Or, as my Dad once noted, getting old isn’t for sissies.
PS – What about all of the other stuff that can be injected in horse joints? Gotta have material for future articles!