What condition is characterized by the flattening of the femoral head?

The condition characterized by the flattening of the femoral head is indeed Legg-Calvé-Perthes disease. This condition occurs primarily in children and involves a temporary loss of blood supply to the femoral head, leading to avascular necrosis. As a result, the bone becomes soft and subsequently flattens due to the weight-bearing pressures exerted on the joint.

In Legg-Calvé-Perthes disease, as the disease progresses, the femoral head can become misshapen, impacting hip joint function and mobility. The condition typically affects children aged 4 to 10 years and can lead to long-term complications if not adequately treated.

Understanding this condition is crucial, as the flattening of the femoral head distinguishes it from other injuries and diseases that affect the hip joint, such as the other options mentioned, which involve different mechanisms or anatomical changes in the hip joint.