Big Henry (R.I.P.) had it when he was 2 years old, and yes he blew the other one out before we could even get him to surgery on the first one. It is really the only option on big dogs. On e little ones they can use mono filament but they can't do that on the big ones. the short story is that he lived, walked and ran again for 11 years with no problems other than some bad days because of weather. They basically re-engineer the knee. Shown here:
At the time Henry had it done, there were few vets that could do it and they had to be trained by the inventor of the procedure. It was pricey like $2,000.00 for each leg. He was a bit bow legged as a result, but his legs were sturdy as ever and he lived a long active life. Rehab was keeping them down for a few days, then towel walking at first so he could "take care of biz", and then daily walks. You are in Fl so let her swim in your pool. Good no impact exercise.
You are in FL. Who is doing the job? I had Henry done when we lived in Clearwater, could it be the same Vet?