How is Legg-Calve-Perthes disease typically diagnosed?

Legg-Calve-Perthes disease is primarily diagnosed through imaging studies, with X-rays being one of the most common initial modalities used. In many cases, the first step in diagnosis involves obtaining plain X-rays to assess the hip joint and look for signs of avascular necrosis in the femoral head. As the disease progresses, X-ray findings may show specific changes, such as flattening of the femoral head, fragmentation, and joint effusion. However, MRI is often used to confirm the diagnosis, especially in early stages when X-ray findings may be inconclusive. MRI is particularly effective because it provides detailed images of bone and soft tissues, allowing for the visualization of the marrow changes associated with avascular necrosis. Thus, while MRI is crucial for definitive assessment, X-ray typically serves as the primary diagnostic tool, particularly for initial evaluation.

Blood tests are not useful for diagnosing Legg-Calve-Perthes disease, as the condition does not produce specific hematologic markers. Similarly, while ultrasound can be useful in evaluating certain pediatric hip conditions, it is not the standard approach for diagnosing this particular disease.