Did you x-ray before you did the SI injection? what kind of injection for “surrounding muscles”?
By hip is your vet referring to the pelvis? As in a pelvic injury, or a hip muscle injury?
Mine had a major injury to his pelvis involving multiple fractures. He was a 5/5 lame, no way you could miss it.
However, I have seen horses with pelvic wing (tip) fractures, which is fairly common as far as pelvic injuries go, and they can range from barely visible to very lame.
1/5 lame on the lunge, would to me, equal no riding.
Do you have a video? How certain is the vet it is hip without any rads or films of the area? I guess that is what the bone-scan is for but palpitation is not a reliable indicator of where the source of the pain is, IME. I have seen horses with suspensory injuries palpitate fine on suspensories and then be very reactive to back palpitations. The other thing is, a horse with SI issues would of course be sore and sensitive to palpitation, but that doesn’t mean the source of the aggravation originates in the SI - I see it all the time with horses with kissing spine. They rarely palpitate sore over the area of actual of crowding or interlapping, but they will palpitate reactively much further down the back. Same goes for horses with hock issues - they usually palpitate sore over the SI but it is not actually their SI that is causing a problem, it’s just distressed by the locomotive compensation and sore as a result.
My experience with pelvic wing fractures, which is the mildest form of a pelvic fracture I think you can go, is that the adduction phase of the limb is usually a little weird - it’ll bow out a little strange compared to the other hind, which will usually be shorter strided – which can throw people off from visually diagnosing the issue because the shorter limb is actually the sounder limb and is being ‘deloaded’ because of the affected limb. I usually see the injured side bows out, the stifle will pop out while the hock seems to wring inward. Usually they are lamer on the lunge and on circles, and much lamer when the injured side is on the inside.
One other thing - they way they stand is usually pretty telling - they tend to camp out with the injured hind leg a bit.
Good luck. A pelvic wing fracture is not usually career ending; its not uncommon in race horses or event horses IME, and after some time off and appropriate layup they’re usually right back to the level they were competing at.
As far as how they get them - usually, it’s from a fall or a knock… sometimes it can be from trailering, or start-gates, sometimes from hitting their hip on something…
As for what we did with my gelding - a long period of controlled/confined movement. He was in a “stall” (12x12 size) for about a month, then was in a very small medical paddock 24/7 (12x30ish) for almost six months. He was cleared to go back into work in March (so 6 months off) and it took about a full year and a half before I did any real work with him. He was brought back to work very carefully - 4 months of hacking walking only, and then about 2 months of once/twice a week trotting, lots of walk poles in between and I did not canter him at all for over six months. He is now almost 2 years post injury and doing LL eventing & dressage.
