I dont mean to pee on your parade but I have some info that you may want to discuss with your vet.
1. The surgery doesnt always work
2. They can sometimes heal on their own, but must have lots of rest.
Have you talked with other vets about cage rest ect..
A friend of mine paid lots of money for ACL sugery and the dog(young rott) reinjured itself about a month later, he then put the dog on strict cage rest and she healed
I hope this helps.