Most healing takes place close to surgery and chances decrease with time. Nerves are fantastic in a way where they can connect by another route when healing and the brain can rewire to get the senses right. E.g people who've been partly paralyzed can sometimes learn to walk even though the old paths will never heal, and it can take long time.
Just as above, I don't have any data to refer to. I would think that after a year one migh have to consider getting used to it, but maybe not rule out entirely.