Lizbud, the injury happened to my Great Pyr about 10 or so years ago. She was jumping down the stairs from my dining room to the front room when she tore the ligament. The surgery was successful and she was able to walk again, however, years later, arthritis set in. I can't remember how long it took for her to recuperate, but I do remember that she wanted to tear off her leg wrapping. It was a while, though, because her leg started to atrophy and looked so skinny when the bandages came off. It didn't take long for the muscles to build up as soon as she was able to do a lot of walking on it again. I'm sure that surgery today will be a lot easier with all the advances made since the early 90's. Good luck with Buddy and let me know what's happening with him.
Sue