Final answer:
The most likely diagnosis for an African American teenager with avascular necrosis of the right femoral head is sickle cell anemia, which can block the blood supply to bones, leading to necrosis. In comparison, fractures more commonly cause avascular necrosis in the elderly.
Step-by-step explanation:
The most likely diagnosis for an African American teenager presenting with avascular necrosis of the right femoral head is sickle cell anemia. This condition occurs when sickled red blood cells obstruct small blood vessels in the bone, leading to a disruption in the blood supply to the femoral head and ultimately causing necrosis. Sickle cell anemia is more prevalent in African American populations, making it a significant consideration in the diagnosis of avascular necrosis in these patients.
As described in the provided references, a fracture of the femoral neck is a common injury in elderly individuals and can disrupt blood supply to the femoral head, leading to bone and cartilage death. However, in the case of a younger patient, particularly an African American teenager, sickle cell anemia is more likely to be responsible for avascular necrosis without the presence of a fracture. It is essential to consider age, medical history, and demographic factors when making a diagnosis.