Just now recovering from a broken hip....
I've mounted the bike (same one I crashed) on a Cycle Ops Fluid 2 in my living room and I am doing a couple of hours a day to stay in shape for the day when I can walk without a cane.
They tell me that the leg will be even stronger than before with the titanium rod in there so I can't say I am too worried.
Although, given the choice , I would pass on a repeat performance!