Legg-Calve-Perthes Disease

Legg-Calve-Perthes disease is a childhood condition that affects the hip joint. It occurs when the blood supply to the rounded head of the thigh bone, called the femoral head, is temporarily interrupted. Without enough blood flow, the bone weakens and can break down, leading to changes in the shape of the hip joint.

The condition most often affects children between the ages of 4 and 10 and is more common in boys than in girls. Over time, blood flow usually returns and the bone heals, but the healing process can take several years. The long-term outcome depends on the child’s age and how much of the femoral head is affected.

Symptoms

Symptoms of Legg-Calve-Perthes disease often develop gradually and may include:

• Limping that becomes more noticeable over time

• Pain in the hip, groin, thigh, or knee

• Stiffness or limited range of motion in the hip

• Pain that worsens with activity and improves with rest

• Muscle weakness in the upper thigh or buttock

• Shortening of the affected leg in some cases

Some children may have mild symptoms at first, which can delay diagnosis.

Causes

The exact cause of Legg-Calve-Perthes disease is not fully understood. The condition develops when blood flow to the femoral head is reduced or temporarily stopped. This lack of blood supply causes the bone tissue to die, a process known as avascular necrosis.

Over time, the body replaces the dead bone with new bone, but during this healing phase, the femoral head is vulnerable to deformation, especially with normal weight-bearing activities.

Risk factors

Several factors are associated with an increased risk of developing Legg-Calve-Perthes disease:

• Age between 4 and 10 years

• Male sex

• Family history of the condition

• Low birth weight

• Exposure to secondhand smoke

• Certain blood-clotting disorders

Despite these associations, many children with the disease have no clear risk factors.

Complications

Complications can occur if the femoral head heals in an abnormal shape. Possible complications include:

• Permanent deformity of the hip joint

• Reduced range of motion in the hip

• Hip pain that persists into adulthood

• Early-onset osteoarthritis of the hip

• Leg length differences

The risk of long-term complications is higher in children diagnosed at an older age or with more extensive bone involvement.

Prevention

There is no known way to prevent Legg-Calve-Perthes disease because the exact cause is unclear. However, early diagnosis and appropriate management can help reduce the risk of complications.

Steps that may support better outcomes include:

• Prompt medical evaluation of persistent limping or hip pain in children

• Following treatment plans to protect the hip joint during healing

• Limiting high-impact activities when advised by a healthcare professional

• Regular follow-up visits to monitor hip development

Early and consistent care plays an important role in preserving hip function as the child grows.