My 11 year old daughter has broken the same ankle 3 times, in the last year.  She also has  had a fracture of her wrist, as well as a compression fracture of her spine.  She had a study called an Osteoquant, and well, nothing difinitive.  The docs just say that the meds make her bones weak.  I dunno anymore.  She did heal ok, but did re fracture the ankle because you can’t get this girl to quit playing soccer!!  It’s scary, but not really any different than having a kid with an injury without CAH.  Just have the injection handy, ask your Endo for coverage doses right after the injury.  Everything should be fine!!  Take care!!