When I was a vet tech, I got to assist on several TPLO surgeries. It's a long procedure, but something that is done regularly, especially with canine athletes.

From the patients I saw, every single one where the owners followed the follow-up advice did fabulously! (Keeping the dog's weight down, following the exercise schedule provided) The only dog I worked with who did NOT do well post-surgery was a dog whose owners allowed him to put on over ten pounds after the procedure!!

A very close friend of mine had a TPLO performed on his older St. Bernard two years ago, and she recovered quickly and last time I saw her was running around the backyard with her little boy.