Fibrodysplasia Ossificans Progressiva Also called FOP for short has affected over 800 diagnosed patients worldwide with one of the most active patient groups in the USA with about 300. This disease is very debilitating because you are not able to control the bone growth easily and once the fibrous tissues have begun forming cartilage there is little hope. High doses of the steroid Prednisone is given immediately at the first signs of a flare up or any injury from falling or general day to day life to slow down the progression.