Strained knee...... Question?

I got grade 3 osteoarthritis in both knee, torn meniscus both knee's, and a torn ACL in my left knee..... I wear custom knee's braces to work out in and am on pain meds and injections but I tend to stay on the elliptical more than treadmill. Very low impact on the knee's and a good source of cardio. I don't know if you are cleared to do light cardio on the elliptical but ck with your doctor. Does your gym have recumbent bikes or even a seated ellitpical?? When my knee's are to bad to workout out I tend to do these cause they take all the weight bearing off my knee's.....