Good luck Eric.
I'm 66 and had knee surgery a few years ago. For my physical therapy afterward my doctor (sports medicine doctor) prescribed riding my bike for 5 minutes (on the trainer) beginning the afternoon of the surgery. In two weeks I had built up to 45 minutes. After 3 weeks he said I could get back out on the road. He told me my running days were over but I could ride till I was 100 -- and I definitely plan on doing it.