Labral tears in the hip are a big deal in the jogging world as evidenced by this
web site .
Note the title of the most popular thread and the number of views/replies.
As a guess, I would think the issue might be related to overtraining (i.e. training for that marathon instead of consistent 10 Ks, or the high level athlete reaching peak conditioning). Eventually, the body just wears down. Cross training and moderation might be the answers but its tough to say. Maybe nutrition is a factor (e.g. avoiding fats, oils at all cost - maybe effecting production of synovial fluid in the joints).