Which portion of the femur should be visible in an anteroposterior (AP) proximal femur radiograph?

The correct answer is the proximal portion of the femur because an anteroposterior (AP) proximal femur radiograph specifically focuses on visualizing the area around the hip joint, which includes the neck, head, and greater and lesser trochanters of the femur. This region is crucial for assessing injuries, fractures, and diseases that may affect the upper part of the femur, where it articulates with the acetabulum of the pelvis.

In this type of radiograph, the goal is to provide a clear image of the proximal femur for accurate diagnosis and treatment planning. The rest of the femur, such as the distal portion and mid-shaft, is outside the primary focus of this specific imaging view, making them less relevant in interpreting issues concerning the proximal femur itself. The medial epicondyle is also not visible in an AP proximal femur view, as it relates to the femoral condyles at the knee, which are not the focus of this particular radiographic assessment. Thus, visibility of the proximal portion ensures that clinicians can effectively evaluate the relevant anatomical structures critical for diagnosis.