Best of luck to you upnover! One thing you may want to do pre-surgery is ask to work with a physical therapist. I was fortunate in that, at the time of surgery, I was working with a phenomenal personal trainer who was well versed in pt and what was needed pre-surgery. Remember that your mid section will be toast - it will be your arms and legs that will be lifting you up and down from the bed, chair, toilet, etc. Your abdominals will not be of use, and that can also put stress on your back. We worked on some exercises that strengthened the other muscles that would need to be used, as well as some functional type movements that would be important in recovery.
When he called to check on me about a week after surgery, I told him I could not thank him enough for working with me the way he did with an eye towards the surgery. It became very evident the first time I tried to sit up how important those other body parts were that had to take up the slack!