I agree look at hoof angles. We were barely negative right hind, it caused some very mild fiber disruption in the suspensory. He has these aluminum onion shoes now that cost a fortune, but it’s been almost a year since the diagnosis and we rechecked his suspensory and it’s still fine in full work.
But I realized lately that we had not injected his SI since, he was getting that done roughly every year. he has no more soreness there at all. Fixing the angles made a huge difference in several issues for a very big, very hard jumping horse.