I often WISH I had not done a hip replacement. I just talked with a young woman, 50, who is a 5K runner (was) and she was having pain so went to surgeon and he told her that a new hip would let her continue to be physical.
She went with a surgeon in the same office where my surgeon is and she's had 3 dislocations so far. She really regrets her decision.
http://www.masterjules.net/hipdisease.htm