I agree with the other posters; but I want to add that while some people are very pro surgery, some are the opposite. I believe it comes down to individual cases and thorough testing and consultations with specialists as you are doing.
I have had both positive and not so positive results with neuro surgery. It is indeed a very tricky field.
My beloved Maxwell who passed in 2006, had disc surgery at Texas A&M in 2004. Maxwell had come to me as an adult and our best estimate when he passed was that he was anywhere from 14 up; so he was perhaps 12 when he had the surgery. This was after he herniated two cervical discs and was unable to stand up on his own. Following the surgery we almost lost him due to his collapsed trachea; but he did recover and did amazingly well.
I agreed to the surgery because I had two options: surgery or let him progress to being a quadridplegic with the later not being a good option and I took the risk. Thankfully, I had two more wonderful years with my beloved Maxwell. He was actually able to stand on his own the day after surgery. It was amazing. What I will say is that back surgery is easier on the pups than it is on humans; but it still is not without risks just as in humans.
I share his story only to give you something to see in terms of surgery being successful...certainly not to suggest that is the right choice for Tobie.
I wish you well in your decision making and hope that things go well for your Tobie.