Overview

Legg-Calve-Perthes (LEG-kahl-VAY-PER-theez) disease is a childhood condition that affects the hip, where the thighbone (femur) and pelvis meet in a ball-and-socket joint.

Legg-Calve-Perthes disease occurs when blood supply is temporarily interrupted to the ball part (femoral head) of the hip joint. Without sufficient blood flow, the bone begins to die — so it breaks more easily and heals poorly.

To keep the ball part of the joint as round as possible, doctors may use a variety of treatments to keep it snug in the socket portion of the joint. The socket acts as a mold for the fractured femoral head as it heals.

Symptoms

Signs and symptoms of Legg-Calve-Perthes disease include:

  • Limping
  • Pain or stiffness in the hip, groin, thigh or knee
  • Limited range of motion of the hip joint

Legg-Calve-Perthes disease usually involves just one hip. Both hips are affected in some children, usually at different times.

When to see a doctor

Make an appointment with your doctor if your child begins limping or complains of hip, groin or knee pain. If your child has a fever or can't bear weight on the leg, seek emergency medical care.

Causes

Legg-Calve-Perthes disease occurs when too little blood is supplied to the ball portion of the hip joint (femoral head). Without an adequate blood supply, this bone becomes unstable, and it may break easily and heal poorly. The underlying cause of the temporary reduction in blood flow to the femoral head is still unknown.

Risk factors

Risk factors for Legg-Calve-Perthes disease include:

  • Age. Although Legg-Calve-Perthes disease can affect children of nearly any age, it most commonly occurs between ages 4 and 8.
  • Your child's sex. Legg-Calve-Perthes is up to five times more common in boys than in girls.
  • Race. White children are more likely to develop the disorder than are black children.
  • Family history. In a small number of cases, Legg-Calve-Perthes appears to run in families.

Complications

Children who have had Legg-Calve-Perthes disease are at higher risk of developing hip arthritis in adulthood — particularly if the hip joint heals in an abnormal shape. If the hip bones don't fit together well after healing, this can cause the joint to wear out early. Hip replacement surgery eventually may be required.

In general, children who are diagnosed with Legg-Calve-Perthes after age 6 are more likely to develop hip problems later in life. The younger the child is, the better the chances for the hip joint healing in a normal, round shape.