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Legg-Calvé-Perthes Disease

Medically reviewed by: Amy W. Anzilotti, MD

Also called: Perthes Disease

What Is Legg-Calvé-Perthes Disease?

Legg-Calvé-Perthes (leg kal-VAY PER-teez) disease is a problem that changes the shape of the top of the thighbone (femur). The bone doesn’t fit into the hip joint normally, causing pain and limping.

Usually, it happens in one hip but sometimes can affect both. Most children with Perthes disease heal well with no long-term problems.

What Happens in Legg-Calvé-Perthes Disease?

The hip is the joint where the leg meets the body. The top of the thighbone is ball-shaped and fits inside a round socket. This ball and socket joint lets us move our legs around in all directions.

In Legg-Calvé-Perthes disease, not enough blood reaches the ball of the hip. As a result:

  • Bone cells in the ball of the hip starve and die.
  • The body starts to break down the ball of the hip.

After a few months, the body starts to rebuild the bone. The rebuilt part could be normal, flattened, or enlarged. If the rebuilt ball is not normal, it may not fit well inside the hip socket, causing problems with moving the hip. The changes happen slowly. It usually takes about 2–3 years from the time symptoms start until the bone is finished rebuilding.

What Are the Signs & Symptoms of Legg-Calvé-Perthes Disease?

Perthes disease can cause:

  • Limping: Often the first sign of Perthes disease is a limp. Parents might notice a change in the way their child walks or runs during sports. One hip may seem stiff or have less movement.
  • Pain: Most kids have some pain in the hip, groin, thigh, or knee.

These problems may come and go, and usually are worse with activity and get better with rest.

What Causes Legg-Calvé-Perthes Disease?

Doctors don't know what causes Perthes disease. Most kids with the condition are 4–10 years old. It is more common in boys.

What Long-Lasting Problems Can Happen in Legg-Calvé-Perthes Disease?

Most kids don’t have any long-lasting problems. Younger kids, and those with less of the thighbone affected, tend to heal best.

But sometimes, even with treatment the bone doesn’t grow back into a shape that fits well into the hip joint. This can lead to:

  • continued pain and stiffness in the hip joint
  • hip pain and arthritis as a young adult
  • needing a hip replacement at a younger age than is typical
  • one leg being shorter than the other

How Is Legg-Calvé-Perthes Disease Diagnosed?

When a child has signs of Perthes disease, the doctor will:

  • ask about the symptoms
  • do an exam to check the hip's movement
  • order X-rays
  • possibly order blood tests to make sure another problem isn't causing the symptoms

How Is Legg-Calvé-Perthes Disease Treated?

Perthes disease usually is treated by a pediatric orthopedist or orthopedic surgeon. Treatment goals are to ease pain, help with hip movement, and help the bone grow back to a normal shape.

The kind of treatments needed depend on a child’s age and the amount and type of changes in the thighbone. The orthopedic specialist may recommend:

Treatment for Legg-Calvé-Perthes can last for several years. X-rays are done at follow-up visits to show how the bone is healing. Sometimes other imaging tests (like an MRI) are needed.

Medically reviewed by: Amy W. Anzilotti, MD
Date reviewed: September 2024