Perthes Disease (Legg-Calve-Perthes Disease) in Children

Perthes disease is a rare childhood condition that changes the hip joint and how bone grows at the top of the thigh bone (femur). It can lead to pain, stiffness and limping. At Banner Children’s, our caring team can help. Learn more about Perthes disease and treatment options.

What is Perthes disease?

Legg-Calve-Perthes disease, often called Perthes disease, is a rare hip condition that only affects growing children.

Perthes disease happens when not enough blood reaches the top of the thigh bone (also known as the femoral head – the ball-shaped part of the “ball and socket” in the hip joint). This ball and socket joint helps you move your leg in all directions.

Over a period of years, the femoral head of a child with Perthes disease breaks down and re-forms. However, this process can cause the hip joint to become painful and stiff and lead to several other issues.

Perthes disease happens in four stages:

1. Initial phase: The femoral head loses blood supply. Parts of the bone turn into dead tissue (bone cells). This phase lasts for several months to a year.
2. Fragmentation phase: The body cleans up the dead bone cells and replaces them with new, healthy ones. This phase lasts for one to three years.
3. Re-ossification phase: New bone regrows and hardens to reshape the femoral head. This phase lasts for one to three years.
4. Healing phase: Normal bone cells replace the new bone cells to form a new rounded shape of the femoral head. This last phase takes a few years, until the child stops growing. 

What causes Perthes disease?

Experts don’t know what causes Perthes disease. Most cases occur randomly. However, there are some known risk factors:

• Age: Perthes disease is seen most often in young children (from ages 2-14) who are small for their age and very active.
• Sex: It is five times more common in boys than in girls.
• Ethnicity: White children are at higher risk.
• Family history: Children with a close relative, such as a parent or sibling, who had Perthes disease are more likely to be affected.
• Secondhand smoke: Children exposed to secondhand smoke may be at increased risk.
• Blood disorders: Perthes disease may be more common in children with conditions that cause blood clotting or clogged blood vessels.
• Low birth weight: Children who had a low birth weight may have a slightly higher risk of developing Perthes disease.

What are the symptoms of Perthes disease?

The first symptoms of Perthes disease are usually a painless limp, favoring one leg, or a change in how your child walks or runs. Children with Perthes disease may also experience the following symptoms:

• Pain and stiffness in the hip, groin, thigh or knee that gets worse with physical activity
• Limited hip movement or range of motion
• One leg seems shorter than the other
• Muscle spasms or muscle loss (muscle atrophy)

These symptoms may be more obvious when your child plays sports. They may also come and go over weeks or months without any injury as the cause.

How is Perthes disease diagnosed?

If your child is experiencing symptoms, contact their health care provider. The provider will review the child's medical history, including any symptoms and family history of Perthes disease or hip problems. They will also examine your child's hip joint, range of motion and overall hip function to look for signs of stiffness, limping or walking problems.

Your provider may also take X-rays to check the shape of the femoral head and look for any signs of bone damage or changes. In some cases, your provider may also order an MRI (magnetic resonance imaging) or bone scans. These tests provide even more details about any bone damage and blood flow to the femoral head.

These tests help rule out other causes of hip pain and can help diagnose Perthes disease. Early diagnosis and treatment are important to best manage the condition.

How is Perthes disease treated?

The goal of treatment is to lessen your child’s pain, protect the shape of the femoral head and restore normal hip movement.

Perthes disease treatment options will depend on your child’s age, the degree of damage to the femoral head and the stage of the disease at the time your child is diagnosed. It may include non-surgical and/or surgical treatment.

Non-surgical options

• Activity restrictions or bed rest
• Pain-relieving medications like ibuprofen (Advil/Motrin) and other non-steroidal anti-inflammatory drugs (NSAIDs)
• Casts or braces to hold the head of the thigh bone in the hip socket and allow it to remold itself into a round shape
• Physical therapy to keep the hip muscles strong and improve range of motion

Surgical treatments

Your child may need a surgery called an osteotomy to hold the femoral head in the hip socket. To do this, a pediatric orthopedic surgeon changes the angle of the hip bones and inserts screws, plates and/or pins to keep it in place. 

Osteotomies are usually not recommended for younger children. They may be considered in older children or those with severe cases.

Following surgery, your child will need physical therapy to restore muscle strength and range of motion. They may also need crutches or a walker to reduce the weight on their hip as they heal.

What is the long-term outlook for children with Perthes disease?

According to the American Academy of Orthopaedic Surgeons, most children with Perthes disease who are treated grow up to live active lives. Each child's experience is unique, but early diagnosis and treatment can improve their long-term quality of life.

Some children with Perthes disease may develop hip-related issues in adulthood including stiffness, joint alignment problems, a difference in leg length and/or hip arthritis at an earlier age than most adults. In addition, those who had Perthes disease as a child may need hip replacement surgery sooner than most adults.

Emotional support and regular check-ups are important for managing the condition throughout the child's growth and development.

Emotional impact of Perthes disease

Children with Perthes disease may feel frustrated, sad or self-consciousness because of their physical limitations. Families may also feel stressed from worrying about their child's well-being.

Support groups and counselors can provide information and offer emotional help for kids and their families as they navigate this condition.

How we care for Perthes disease at Banner Children’s

If you have concerns that your child has Perthes disease, contact Banner Children’s. Our orthopedic hip specialists offer your child complete care to cover all of their needs. We will also explain all treatment options and offer support to help you get the best care for your child.