Damaged collateral ligaments in horses hoof. has anyone had or know a horse whos suffered this injury?

vet has given a guarded prononsis for returning to full work as all round competion horse. i can live with that, will just be happy to get him back sound and to hack and a bit of dressage. he has to have 6-9 mths box rest with controlled walking exercise starting with 5 mins a day. has anyone got any experience of this injury good or bad. thanks