Term,
I had a knee replacement about 18 months ago so I know what you are facing. Get a bunch of books. You will have to spend many hours on an exercise bike and a book makes the time pass. Also, and this is important, be very serious about the physical rehabilitation work. You will have to work hard and put up with some pain. You will also go through a bunch of ice (zip lock bags are a must) to get rid of post-exercise pain.
With a titanium knee and a titanium hip I am hiking, hunting, lifting weights and getting around great, you can do this too. A well equipped weight room at a good gym is a place you will get to know very well.
I wish you well. Do the work and you will be OK. It is difficult, but worth it.
Joe