Legg-Calves-Perthes Disease

What is Perthes Disease?

Legg-Calvé-Perthes disease, or Perthes disease, as it is usually called, is a rare condition of the hip bone that affects only children. It is characterized by a temporary loss of blood supply to the hip. The lack of an adequate blood supply causes the head of the femur bone to die. This process is called osteonecrosis.

Who gets Perthes disease?

Perthes disease is rare, afflicting about one in 1,200 children. Perthes disease usually affects children between the ages of 4 and 10. The average onset age is 6. It is five times more common in boys than in girls. It often affects children who are very active, even athletic. Fewer than 5% of children with Perthes disease are affected in both hips.

What are the causes of Perthes diseases?

The causes of Perthes disease are not known. However, children who are short for their age, or who are extremely active, may be at higher risk. The disease is also more common in Asians, Eskimos, and Caucasians. There is a much lower incidence rate in Native Americans, people with African heritage, Polynesians, and in Australian aboriginals.

Exposure to secondhand smoke may also increase a child's risk of Perthes disease, although the exact reasons why are not known.

What are the symptoms of Perthes disease?

The first symptoms of Perthes disease are usually limping, or mild pain in the hip area. The child may not even notice he or she is limping. It may be the parent who first sees this while watching their child play. Pain may occur on and off for months. It may be felt in the hip, or areas around the hip, as the child compensates for lower hip mobility by overusing muscles around the hip. This pain may be in the groin, thigh, or knee. The affected area may also appear inflamed and irritated.

Sometimes, the child may feel no symptoms. Perthes disease might not be noticed until an X-ray taken due to a fall or other injury shows that the child is affected by the condition.

If your child has any of the above symptoms and you suspect he or she may have Perthes disease, you should consult your pediatrician immediately.