My father's Parkinson's and a question about a possible back surgery

My father has been diagnosed with Parkinson 2 years ago and prior to that for many years he had been suffering with back pain (around 15 years). Currently he finds walking very difficult and we are considering back surgery. His Parkinson doctor is against an operation and has warned us of the complications after the operation while the surgeon is in favour of the operation. I just wondered whether anyone with PD has been through a back surgery and what results have they gained? Were there any complications?

I really appreciate your feedback on this issue as my father is finding walking more and more difficult.