Hind suspensories have a worse prognosis, as you likely know.
I did have a horse with a full blown suspensory rupture, but up front. It was caused by my own ignorance - I did not know at the time to look at feet critically, and he had awful angles up front and NPA behind. The farrier had come about two days before, and we were in the middle of a HJ round when his suspensory completely failed on him. Looking at those old photos of his, I don’t know how he was as sound as he was for years. I was still relatively new to horse ownership and really wish I knew then what I knew now.
He was so unmanageable during stall rest that after only a few weeks in, we just turned him out. He was miserable to the point of causing more damage by weaving and stall-walking. He was out of work for 2 years. At the time we thought he’d never come back to ridden work, so I actually picked up a 3 y/o project who became my main horse. Retired life didn’t really suit the suspensory horse and he started coming to me and being offended when I took the 3 y/o out of the paddock instead of him. He had such a big personality – probably why he was such an awful stall rest candidate
Vet came and ultrasounded him and gave him the clear to return to work. I started him back into work around month 23. It’s been so long that the details are fuzzy, but I remember the first 6 months we only trail rode with lots of terrain. He resumed his prior level of work and then some, becoming a Novice packer for my younger sister for years. During the injury we’d been HJers and did 2’6 classes. Shortly after his injury I converted to eventing, and he became the World’s Best XC horse. We had a solid ten years of good riding with him after he healed from his injury.
In your shoes, if you can do it, I would do Dr Green if the ultrasounds show some fiber pattern healing and the vet okays it. Sometimes they are such bad patients that stall rest doesn’t mean they’re healing. In my gelding’s case, I’m convinced that the reason he came back so strong was because being out on turnout 24/7 conditioned his limbs far better than a stall ever could.
Also consider seriously investigating the hooves. Knowing what I know now, I realize many PSD and suspensory injuries tend to show up with NPA behind. While correlation doesn’t equal causation, I’ve seen enough of it now to be confident that the hooves play a huge part in suspensory injuries.
Something else to consider is, I don’t think it’s a fluke that horses on 24/7 turnout suffer fewer soft tissue injuries.