OH DUH......I just realized you said LP surgery....not a torn ligament.
I never do LP surgeries except on young pups!!! The reason not to do it in adults is because the knee is unstable and has been wearing on the cruciate ligament. The surgeon I use never recommends surgery unless the pup is unable to use that knee because often once you repair the knee, the ligament will tear later and you are looking at another surgery!
So sorry I misread your post. If your surgeon is not board certified, I would get a second opinion before doing anything else!!
You can find one at:
www.acvs.org