Legg-Calve-Perthes (LEG-kahl-VAY-PER-tuz) disease is a childhood condition that affects the hip. The thighbone and pelvis meet in a ball-and-socket joint. Legg-Calve-Perthes occurs when blood supply is temporarily interrupted to the ball part of the joint. That part of the bone then breaks more easily and heals poorly. The cause of the condition is not known despite considerable research.
Although Legg-Calve-Perthes disease can affect children of nearly any age, it's most common among boys ages 4 to 8.
Treatment focuses on keeping the ball part of the joint as round as possible while it heals, which can take two years or more. In some cases, physical therapy, exercises or casts are used to hold the ball firmly within its socket. Surgery is also an option, but most children with Legg-Calve-Perthes disease recover well without surgery.
Signs and symptoms of Legg-Calve-Perthes disease include:
- 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, but both hips are affected in some children.
When to see a doctor
Make an appointment with your doctor if your child begins limping or complains of hip, groin or knee pain.
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 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.
Children who have had Legg-Calve-Perthes disease are more likely to develop early osteoarthritis in the affected hip.
Preparing for your appointment
You'll probably first bring your concerns to the attention of your child's doctor. After an initial evaluation, your child may be referred to a doctor who specializes in bone problems in children (pediatric orthopedist).
What you can do
Before your appointment, you may want to write a list of answers to the following questions:
- When did these symptoms begin?
- Does any particular leg position or activity make the pain worse?
- Have any of your relatives had similar symptoms when they were children?
- Does your child have any other medical problems?
- What medications or supplements does your child take regularly?
What to expect from your doctor
Your doctor may ask some of the following questions:
- What are your child's symptoms?
- Have they gotten worse over time?
- Do the symptoms seem to come and go?
- Is your child active?
- Has your child experienced an accident or injury that might have caused hip damage?
- If your child's symptoms include pain, where is the pain located?
- Does activity make your child's symptoms worse?
- Does resting ease your child's discomfort?
Tests and diagnosis
During the physical exam, your doctor may move your child's legs into various positions to check range of motion and to see if any of the positions cause pain.
These types of tests are vital to the diagnosis of Legg-Calve-Perthes disease and may include:
- X-rays. Initial X-rays may look normal, because it can take several weeks after symptoms begin for the damage associated with Legg-Calve-Perthes disease to become evident on X-rays. Your doctor may recommend several X-rays over time, to track the progression of the bone damage.
- Bone scan. In this test, a small amount of radioactive material is injected into a vein. The material is attracted to areas where bone is rapidly breaking down and rebuilding itself, so these areas show up on the resulting scan images.
- Magnetic resonance imaging. This technology uses radio waves and a strong magnetic field to produce very detailed images of bone and soft tissue inside the body. MRIs often can visualize bone damage caused by Legg-Calve-Perthes disease before X-rays can.
Treatments and drugs
As Legg-Calve-Perthes disease progresses, the ball part of the joint (femoral head) weakens and fractures — losing its nice round shape. The goal of treatment is to keep the femoral head as round as possible, so the hip will work properly in the future. Doctors use a variety of treatments to keep the femoral head snug in the socket portion of the joint. The socket acts as a mold for the fractured femoral head as it heals.
The length of time required for healing will vary, depending on the severity of the bone's damage. In most cases, treatment will last for two years or longer.
If your child is 7 or younger and the femoral head is still fairly round, your doctor may suggest nonsurgical treatments such as:
- Exercises. As the hip stiffens, the muscles and ligaments around it may shorten. Stretching and strengthening exercises can help keep the hip more flexible.
- Crutches. In some cases, your child may need to avoid bearing weight on the affected hip. Using crutches can help protect the joint.
- Traction. If your child is in severe pain, a period of bed rest and traction may help. Traction involves a steady and gentle pulling force on your child's leg.
- Casts. To keep the femoral head deep within its socket, your doctor may recommend a special type of leg cast that keeps both legs spread widely apart for four to six weeks.
Nonsurgical treatments don't work as well in children older than 7, perhaps because their bones aren't as moldable as those of younger children. Surgery may also be a better option for children with more-severe bone deformities. Surgeries used to treat Legg-Calve-Perthes disease include:
- Contracture release. Legg-Calve-Perthes and the immobility imposed by some of its treatments can shorten nearby muscles and tendons, which may cause the hip to pull inward (contracture). Surgery to lengthen these tissues may help restore the hip's flexibility.
- Loose body removal. In some children, the damage to the femoral head can result in loose bits of bone or torn flaps of cartilage. Surgically removing this misplaced tissue can help the hip joint move more smoothly.
- Hardware implants. If leg casts can't place the ball and socket in a healthy position, your doctor might suggest changing the position of the ball and socket. This may involve the use of metal hardware such as screws, wires or plates.
- Joint realignment. If the femoral head doesn't match up well with its socket, surgeons can alter the angle of the thighbone or the pelvis to bring the two bones into better alignment.
Lifestyle and home remedies
Home care measures to reduce pain and prevent damage include:
- Activity modification. Your child should avoid high-impact activities, such as running or jumping, because they can increase the amount of damage to the weakened bone.
- Pain medication. Over-the-counter medicines such as ibuprofen (Advil, Motrin, others) can help relieve pain and reduce joint inflammation. Don't give your child aspirin as it's been linked to a rare, but serious, condition called Reye's syndrome.
- Heat or cold. Hot packs or ice may help relieve hip pain associated with Legg-Calve-Perthes disease. Using heat before stretching exercises can help loosen tight muscles.