This a condition which starts which decrease in blood flow to the femoral head. The cause is unknown. Most common age group is 4years -8 years. Male are more commonly affected. This conditions can cause permanent disability of the hip. For management purpose there are four stages of Perthes disease.

Treatment- principle of treatment is decrease the pain, increase the hip movement and decrease the permanent deformity of the head. Varus De-rotation Osteotomy is the surgery currently performed with high success.