Explanation:
Legg-Calvé-Perthes disease is a pediatric condition involving idiopathic avascular necrosis of the femoral head. The disease progresses through stages including fragmentation, collapse, and eventual reossification. It typically affects children between 4 and 10 years of age. Radiographs demonstrate fragmentation and flattening of the femoral head. Treatment focuses on maintaining femoral head containment within the acetabulum. Early intervention improves long-term hip morphology and function. Reference: Perthes G. "On Juvenile Deforming Arthritis of the Hip." Journal of Bone and Joint Surgery, 1910.