"My dog has luxating patella?" It happens, nothing anyone here can do for you and your dog, discuss it with the diagnosing/treating vet and learn how to ask a question as placing a question mark after a statement is not a question but is a reportable violation of YA guidelines.
Ranting is also a reportable violation of YA guidelines, which you continue doing as well.
No one, including a vet, has examined your dog or know your dogs past medical history, which obviously can't be done sight unseen on line anyway, don't trust your vet, then get a second opinion from another or a specialist and/or a vet teaching college.
Surgery always has risks, the older the dog, the higher the risk. I've never had a dog with this issue, however, whether I or anyone has or has not is not important as each case is individual. This is about your dog, not anyone else, or their dog or dogs.
Voice all your concerns to your vet, not strangers/children on line.