I hope this is the right place to put this. Last year I was diagnosed with bone cancer and ended up loosing my left femur. I still have my left leg, but the entire femur was removed and replaced with an internal prosthesis. The problem now is that my knee cannot bend more than 50 degrees and is very uncomfortable at anything past 30. I understand that normal riding would impossible like this. There is a possibility that with additional surgery I could increase the bending to 90 degrees. Would it be possible to ride with this handicap? Any thoughts or suggestions on possible bikes, modifications, equipment, anything at all that might help me would be appreciated so much.