Very strange that your dog has the same symptoms. How old is your dog?
They did an mri already?
Is your dog able to walk right now?
My dog is able to hobble along, but tends to start to do the bunny hop. You can see her back knee push outward as she walks.
She seems to have a bit more stability, but not sure if that is just her adjusting to this. Don't think the prednisone is doing anything, as I would have thought to see more of a difference.
Is your dog on any meds right now?
What does your vet think is wrong?