Legg-Calve-Perthes Disease (LCPD) is a deterioration of the top of the thighbone (femur) due to insufficient blood supply. We don’t know what causes LCPD, but doctors think it may be related to growth hormones. It can strike children throughout the growing years. Boys get it four times as often as girls. It is more common in children ages 4 to 8, and those who are small for their age. Without treatment, your child may lose the ability to rotate his or her hip, thereby worsening a limp.