I started when I was 4 and stopped when I was 23. The only thing I ever got was tendinotis once and I'm not even sure it was because of ballet. It has to be said I never did more than 1 1/2 hours a week and never entered any kind of competition or professional event but I guess only very intense ballet dancers get the ailments you mentioned.
Maybe it's because I'm (much!) older now but I've got more injuries since I started doing Irish dancing than I ever had in my 20 years of ballet/12 years of tap dance/4 years of figure skating/4 years of ballroom dancing.