Jon,
You and your father will both be in my thoughts and prayers these next few days. Things have come a long way in the field of back surgery, I have had spinal fusion surgery twice in my life to repair ruptured discs. I have been pain free for almost 10 years since the last operation. Going under the knife is a stressfull time and I'm sure your father deep down knows that you care for him. Good luck on the surgery and the recovery. That may be the time that you and your father mend old wounds.
Brian