Revision. I had metal on metal issues. Big mess. Hopefully all better now. In terms of time frame, I think it depends on what exterior (skin) nerves that were cut during surgery. It may be they are learning the right angle of incision now and not so much nerves are cut. RN told me my doctor is cutting in a slightly different angle now. But for me, he wanted to keep from having an "x" on my hip, so he cut through old scar.
Again the numbness never bothered me. Numbness went from scar to 2-3 inches back. More of a curiosity for me than any real issue. Remember, nerves are everywhere. Drs try not to cut them, but damage to little/minor nerves are normal (at least from what I hear). Major nerves are a different story. They do all they can to stay away from them. The sciatic nerve is about an inch from the joint. Drs really try to protect that one.