Some's been mentioned already. Saddle at proper height, shorter cranks will help minimize the range of motion your knee must do. Using low ratio gears and spinning a higher cadence will instead of mashing at a low cadence will keep you the same speed with less strain on your joints and bones. A e-bike will also let you keep from having to put a lot of strain on your bones and joints.
I was told when my parents bought my first store bought bike back in the early 70's that it's not how hard you pedal that makes you healthy. It's just that you pedal. Easy pedaling is better than hard pedaling. And the longer you can pedal the better for your cardio health.