Loss of blood to the head of the femur (thigh bone) is called Perthes' disease. There are four stages to this condition. Treatment depends on which stage the child is in when the diagnosis is made.

Stage one (initial stage) is often unnoticed as often there are no symptoms. Many children are diagnosed in stage two (sclerotic stage) when pain and a limp become obvious. It's best if treatment can be started in this stage. The goal is to decrease inflammation, pain, and muscle spasm around the hip. Drugs, rest, and physical therapy are used to do this.

Stage three (necrotic stage) ends with stage four called reossification. During this and the final healing stage the goal is to keep the femoral head as round as possible and in the hip socket. It may be necessary to use casts, braces, or even surgery during this stage.

Surgical treatment may be needed much later if there is a leg length difference from lack of growth on the Perthes' side.