One of my friends who is a fourth year med student at IU told me a joke:
They pith (destroy the brain with a blunt instrument) the bottom 10% of the medical school graduating class. Those that can crawl away after this go into gastroenterology, proctology, family practice, etc. Those who can not crawl away become orthopedic surgeons.
I remember reading a piece of advice somewhere: don't mess with orthopedic surgeons- they are strong as oxen and almost as smart.