What is Legg-Calvé-Perthes disease

Legg-Calvé-Perthes disease is a childhood hip disorder characterized by the temporary loss of blood supply to the ball of the hip joint (the femoral head), leading to bone tissue death and subsequent structural changes. Currently, 227 people with Legg-Calvé-Perthes disease have joined the DiseaseMaps community to share their experiences and navigate this complex diagnosis together.

What exactly happens in Legg-Calvé-Perthes disease?

In Legg-Calvé-Perthes disease, the blood supply to the femoral head is interrupted, a process known as avascular necrosis. Without adequate blood flow, the bone cells die, causing the femoral head to weaken and potentially collapse or lose its spherical shape. Over time, the body attempts to repair the bone through a process of revascularization and remodeling. How well the hip joint heals depends largely on the age of the child at onset and the extent of the bone damage, as the goal of treatment is to keep the femoral head contained within the hip socket while it rebuilds.

Who is typically affected by Legg-Calvé-Perthes disease?

This condition primarily affects children, with the most common age of onset occurring between 4 and 10 years old. It is estimated that Legg-Calvé-Perthes disease occurs in approximately 1 in 1,200 children. Interestingly, boys are affected four to five times more frequently than girls. While the exact cause remains idiopathic (unknown), researchers believe that a combination of genetic predispositions, clotting disorders, and environmental factors may contribute to the disruption of blood flow.

How is Legg-Calvé-Perthes disease classified?

Medical professionals use several classification systems to determine the severity of Legg-Calvé-Perthes disease based on how much of the femoral head is affected and how far the healing process has progressed. The most common systems include:

• Waldenström’s Classification: Tracks the four stages of the disease: initial (necrosis), fragmentation, reossification, and healed.


• Herring Lateral Pillar Classification: Used during the fragmentation stage to predict the long-term outcome by assessing the height of the lateral portion of the femoral head.


• Catterall Classification: An older system that evaluates the degree of femoral head involvement based on X-ray findings.

How does this differ from other hip conditions?

Unlike transient synovitis, which is a short-term, self-limiting inflammation of the hip, Legg-Calvé-Perthes disease involves permanent bone tissue death and a lengthy recovery process often spanning 18 to 24 months. It is also distinct from Slipped Capital Femoral Epiphysis (SCFE), which involves the physical displacement of the femoral head growth plate, whereas Legg-Calvé-Perthes disease is fundamentally a vascular issue affecting the blood supply to the bone itself.

Next steps

• Consult a pediatric orthopedic specialist immediately if your child experiences a persistent limp or hip, groin, or knee pain.


• Request an MRI or X-ray imaging to confirm the diagnosis and determine the current stage of the condition.


• Join the DiseaseMaps community to connect with other families who have navigated the challenges of Legg-Calvé-Perthes disease.


• Discuss physical therapy and activity modification with your clinical team to preserve hip joint range of motion.

Medical disclaimer: This content is for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment; always seek the advice of your physician with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Legg-Calvé-Perthes disease


• Orphanet: Legg-Calvé-Perthes disease (ORPHA:2910)


• OMIM (Online Mendelian Inheritance in Man): Legg-Calvé-Perthes disease


• International Perthes Study Group (IPSG) clinical resources