First and foremost, good luck with your health and recovery.
While I have had my share of knee work done, I haven't had a total knee replacment. I was able to come back pretty quickly several yrs ago and really pushed myself - I don't know if I would be so fortunate now.
I would think that much of this is on an individual and depends on a great many factors - age, weight, athleticism, abitlity to heal, time to rehab, drive and determination, etc.
I certainly wish you good luck and hope you come back 100%.
Volleyball in your future?