Hi Dinos,
I haven't had my knees replaced, but have had two right hips and am about to have my left done very soon. From what I've seen on the ward, recovery from hips is much the same as knees, i.e. out of bed the next day, mobilising with a physio and as soon as you can manage stairs you can go home on crutches or frame. I've seen most patients discharged after 4-7 days.
How quickly you can have a second knee done would depend how well you recover from the first, but all being well, probably 3 months later would be the earliest, once you've healed and strengthened muscles around your new knee to be able to weight bear whilst the other knee is recovering. I know with hips it takes 12 weeks for everything to heal inside around the capsule.
If you don't mind me asking, why are you waiting 1-2 years before going ahead?
My first new hip was a full ceramic but my revision is half ceramic. As for ceramic knees, I'm not sure, but I know each surgeon has his/her own ideas what is best for each patient and depending upon your age, what kind of wear you're going to get from it. The younger you are, the more likely you'll be given a ceramic, providing its available.
Everyone having hips and knees replaced is asked to join the National Joint Registry, but its not compulsory.
http://www.njrcentre.org.../njrcentre/default.aspx
Carol