Legg-Calve-Perthes disease

Overview

Legg-Calve-Perthes (LEG-kahl-VAY-PER-tuz) disease is a childhood condition that occurs when blood supply to the ball part (femoral head) of the hip joint is temporarily interrupted and the bone begins to die.

This weakened bone gradually breaks apart and can lose its round shape. The body eventually restores blood supply to the ball, and the ball heals. But if the ball is no longer round after it heals, it can cause pain and stiffness. The complete process of bone death, fracture and renewal can take several years.

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

Symptoms

Symptoms of Perthes disease include:

• Limping.
• Pain or stiffness in the hip, groin, thigh or knee.
• Limited range of motion of the hip joint.
• Pain that worsens with activity and improves with rest.

Perthes disease usually involves just one hip. Both hips can be affected, but they usually are affected at different times.

When to see a doctor

Make an appointment with your healthcare professional 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

Perthes disease occurs when too little blood reaches the ball portion of the hip joint for a short time. Without enough blood, this bone becomes weak and collapses. The cause of the reduced blood flow is unknown.

Risk factors

Risk factors for Perthes disease include:

• Age. Perthes disease can affect children of nearly any age, but it most commonly begins between ages 4 and 10.
• Your child's sex. Perthes is about four times more common in boys than in girls.

Complications

Children who have had Perthes disease are at higher risk of developing hip arthritis in adulthood — especially if the hip joint has poor healing. If the ball-and-socket joint doesn't fit together well after healing, the joint can wear out early.

In general, children who are diagnosed with Perthes disease after age 6 are more likely to develop hip conditions later in life. The younger the child is at the time of diagnosis, the better the chances for the hip joint to heal in a typical, round shape.