The malleoli are used as landmarks in radiographic positioning of the _____.

The malleoli, which are the bony prominences on either side of the ankle, serve as critical landmarks in radiographic positioning of the ankle. When performing radiographs of the ankle, accurate positioning is essential for obtaining clear and diagnostic images. The medial malleolus (the bony knob on the inner side of the ankle) and the lateral malleolus (on the outer side) provide reliable references for aligning the patient's foot and leg in relation to the X-ray beam.

Proper alignment utilizing these landmarks helps in depicting the anatomy of the ankle clearly, allowing for effective assessment of any underlying conditions, fractures, or abnormalities. Utilizing the malleoli ensures that the subtalar joint and the tibiotalar joint are appropriately visualized in the imaging process.

In the context of the other options: the knee, elbow, and wrist have their own respective anatomical landmarks that are more relevant for positioning in their imaging techniques, but none of those structures rely on the malleoli as critical markers for accurate radiographic presentation. Therefore, the focus on the malleoli makes the ankle the correct choice regarding the use of these anatomical landmarks in radiographic positioning.