My sister and my father have both had rottweilers, and they have all needed cruciate ligament ops, (at different times in their lives) and being heavy dogs they took quite a bit of recovery time, and with one very active rottie, it was quite difficult to stop her jumping around and re-breaking it! we also tried to keep their weight down as much as possible - none had been obese, but it is better if they are as light as they can be.) They all recovered well, and you wouldn't have known they had had a problem. Good luck with what you decide is the best for your dog.