I'd really talk to your Dr about this but if your body is used to it I'd guess it's OK in general. I mean, that is what they say...
However: I'd say take it really really easy after a procedure. After all, your body is NOT used to that and, if hopefully soon, you do get PG you'll have to change your work load anyway... and for you I mean that literally!
Making a pure guess, though: I am guessing better to ride than walk. All that walking would put your body in athletic mode, which tends to mess with cycles and such.
Good luck to you and I hope there is an easy answer!