I've always thought the recumbent exercise bikes were easier on the back and I have lower back pain from arthritis. I had a combination recumbent bike and elliptical combination (Proform Hybrid Trainer) - The one I had was an older and less expensive version of the current one here - https://www.proform.com/hybrid-trainers/hybridtrainer. Last summer I replaced it with a Teeter FreeStep Cross Trainer to get a more natural like walking up and down motion with my legs and also better to help with upper body strength which I need - https://teeter.com/product/freestep-lt1/.

All of the before and after exercises were specifically to help with the rehab of the knee after the surgery - the stronger the leg and muscles/tendons around the knee, the easier it will be to get back to normal after the surgery. I don't think it would have helped to avoid having the surgery.