Legg-Calve-Perthes disease affects the growing end of the femur bone that fits into your child’s hip socket. It causes the end of the bone to break down and then regenerate over several years. This process can alter the shape of the bone and how it fits in the socket. Your healthcare provider will work to prevent or correct this deformity.
Legg-Calve-Perthes disease is a rare condition that affects the hips of children aged 2 to 12. It starts when the head of the femur bone (the “ball” in the “socket” of the hip joint) temporarily loses its blood supply. When blood stops flowing to the bone, the tissue starts to die. After a while, the blood flow returns, and the bone slowly repairs itself. But it may not have its original shape and size.
Legg-Calve-Perthes disease belongs to a group of disorders called osteochondroses, which involve the degeneration and regeneration of the growing end of a bone. It occurs unexpectedly and for unknown reasons. It progresses in stages, and the whole process can take several years. How much it affects your child depends on how much their bone changes. With treatment, the long-term prognosis (outlook) is good.
Legg-Calve-Perthes disease (LCPD) goes by various other names, including:
Estimates suggest Legg-Calve-Perthes disease affects around 1 in 12,000 children worldwide. It’s five times more common in kids assigned male at birth (AMAB) than kids assigned female at birth (AFAB).
Perthes disease is most common in kids ages 5-7. But it can affect kids as young as 2 or as old as 12.
Perthes syndrome triggers a process of degeneration and regeneration in your child’s femur bone, which can last several years. The condition is temporary, but it can cause permanent changes.
If the shape of your child’s femur head changes a lot, it might not fit properly in their hip socket anymore. Treatment can help, but if it continues not to fit, they can develop hip problems later in life.
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Signs and symptoms of Perthes develop over time and often with no clear beginning. You or your child might start to wonder what’s up when symptoms appear and don’t seem to ever get better.
Early symptoms might include:
Later signs and symptoms of LCPD may include:
Perthes disease develops when blood supply to the head of the femur bone temporarily slows or stops. This is called ischemia. Since the bone depends on blood supply for oxygen and nutrients, it starts to die and break down without them. This process is called avascular necrosis (osteonecrosis).
Normally, ischemia might happen if a blood vessel gets blocked or compressed. Artery disease or a blood clot might block it from the inside, or swelling might compress it from the outside. But researchers don’t know what causes ischemia in LCPD. It’s possible that different things cause it in different kids.
Research suggests that about half of kids who develop LCPD have some type of blood clotting disorder. Another suggested cause is a traumatic injury or repetitive strain injury that caused enough swelling to cut off blood flow to the bone. Around 10% of cases seem to relate to an inherited gene mutation.
Factors that may increase your child’s risk of developing Legg-Calve-Perthes include:
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While Legg-Calve-Perthes is active, the head of your child’s femur bone in their hip socket will go through a process of degeneration (breakdown) and then regeneration (rebuilding). The breakdown phase may take up to a year, and the rebuilding and remodeling phase may last two to five years.
Some kids have more tissue loss than others. This might be because they have more severe ischemia, or it lasts longer, or they use their bone too much while it’s weakened, causing additional damage. In some kids, the rounded heads of their femurs collapse and flatten. This makes them fit poorly in their hip sockets.
When the bone begins to rebuild, it has another chance to restore its proper shape and fit. But different kids have different amounts of regrowth. Some femurs never recover their former size and shape. Others may overgrow the hip socket. Your healthcare provider will try to influence these outcomes.
Some kids might need to immobilize their hips in a cast for some time. Others might need surgery. These treatments can help the bone regrow correctly. Kids who continue to have poorly fitted hip joints will have ongoing symptoms. Hip dysplasia (a poor fit) can lead to complications like arthritis later in life.
A healthcare provider will begin with a thorough physical examination, then follow up with X-rays to look at your child’s bones. X-rays can show evidence of Perthes syndrome, as well as the stage and severity of the disease. In some cases, they might order an MRI (magnetic resonance imaging) to see certain features in more detail.
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Treatment for Legg-Calve-Perthes depends on how severe the disease is, what stage it’s in and how old your child is. In general, younger kids, whose bones grow faster, tend to do better with less intervention, while older ones might need more. A healthcare team will develop a personalized treatment plan.
This plan may include:
Unfortunately, no. There are no known ways to prevent Perthes disease.
If your child has developed Legg-Calve Perthes, you can expect a healthcare journey of several years, with different phases in it. This will intrude on their childhood, to some extent — less for some than others. But when it’s over, most can return to their activities without limitations or ongoing symptoms.
If your child is younger than 7, they’re more likely to recover fully with conservative treatments. If they’re older than 7, they’re more likely to need surgery. Kids who don’t get the right treatment at the right time, and whose femur bones remain deformed, can develop hip osteoarthritis later in life.
If your child has Legg-Calve-Perthes, you’ll probably have many questions about their treatment and expected prognosis. Your provider will do their best to forecast what to expect for your child.
You might want to ask:
Legg-Calve-Perthes is an unexpected diagnosis that’ll bring a lot of questions. Once your healthcare provider has explained your child’s individual condition, you can begin to settle into a rough idea of what to expect. The next step will be to explain it to your child in a way they can understand.
There’s a lot of reasons for optimism. Most kids don’t have too much discomfort once they’re in treatment. They might have some limitations, but they’re usually temporary. They’ll need to have some type of orthopedic therapy before they’re through. But in the end, they’re likely to fully recover.
Last reviewed on 08/27/2024.
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Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy