A, Anteroposterior radiograph showing an external fixation device. The radiopaque hardware that could potentially cause streak artifacts on CT—the thick metal pin through the calcaneus (white arrows), the distal pin-bar clamps (white arrowheads), and the proximal pin-bar clamps (black arrowheads)—are below and above the pilon fracture and thus will not
be in the axial CT scanning plane through the fracture. The longitudinal carbon fiber connecting bars are barely radiopaque, and as such they are barely discernible on this
radiograph (gray arrows). These will cause no CT streak artifacts. B, Coronal plane CT scan. The carbon fiber connecting bars (gray arrows) cause no CT streak artifacts across the fractures. The CT streak artifacts from the metal percutaneous pin (white arrows) and pin-bar clamps (white arrowheads) are all distal to the pilon fracture and only minimally effect visualization of the calcaneus cortex. C, Axial plane CT scan through the level of the fractured plafond. The carbon fiber connecting bars (gray arrows) cause no CT streak artifacts across the fractures. D, Sagittal plane showing the talar dome impacted into a large cortical gap in the plafond. This is the type of visual information the surgeon needs to plan the open reduction and internal fixation. The white arrow shows the percutaneous pin passing through the calcaneus.
- CT and MRI of the Whole Body fifth edition