Lyda, I am still pre-op but have you tried swimming or water arobics these are kinder to your back and joints. Don't give up hope. There are many places you can go ie.. YWCA, WMCA, even the High School here has adult swims seporate from all the kiddies. You can do Laps or exercise. Also Check with your local Community Education programs
Good luck and keep Moving
Lynette