Perthes' disease is a degenerative condition affecting the hip joints of children, typically between the ages of 4-8 years. It is due to avascular necrosis of the femoral head, specifically the femoral epiphysis. Impaired blood supply to the femoral head causes bone infarction.

Perthes' disease is 5 times more common in boys. Around 10% of cases are bilateral

Features

• hip pain: develops progressively over a few weeks
• limp
• stiffness and reduced range of hip movement
• x-ray: early changes include widening of joint space, later changes include decreased femoral head size/flattening

Investigations

• plain x-ray
• technetium bone scan or magnetic resonance imaging if normal x-ray and symptoms persist

Management

• To keep the femoral head within the acetabulum: cast, braces
• If less than 6 years: observation
• Older: surgical management with moderate results
• Operate on severe deformities

Prognosis