Where is your range limited? At the bend, or bottom of stroke?
60* sounds quite doable, but the issues will vary according to where the movement is. If you set your saddle low, assuming extension issues, you could ride, but it will lead to ITB issues and pain behind the kneecap if you ride long distances. Alternately, if it is bending issues, high saddle and shorter cranks can help.
My knee has ROM issues as well and it has taken me a great deal of trial and error to find a comfortable and workable situation for my condition.