Sickle cell anemia: An inherited blood cell ailment that is definitely characterised by abnormally formed hemoglobin that usually takes the shape of a sickle. These sickled cells are fragile and at risk of rupture and don't function as usual purple blood cells. Main exercise routines might also assist with steadiness https://www.theorthopaedicandpainpractice.com/what-is-avascular-necrosis-of-the-hip/?_gl=1*xbbxlb*_up*MQ..&gclid=Cj0KCQjwkt6aBhDKARIsAAyeLJ2krYJSOuy5mZksrNqH-VDjQwW1ScD49yD8BUWysDG6u6bJPCSbXVUaAuCPEALw_wcB