Find the fracture in this patient with blunt knee trauma.
As a general rule, plain films are insensitive in ruling out orthopedic injuries. One particularly tricky area is the knee. This 2-view knee series above is normal.
Did you know that the sensitivity of picking up knee fractures is as low as 79% with a 2-view series and 85% with a 4-view series? With the advent of CT imaging, more and more subtle fractures are being found.
Here is the same patient with 2 oblique views:
Although oblique views add more sensitivity in detecting fractures, these are also normal. However in the CT reformats of this patient's knee, the fracture becomes obvious - a depressed lateral tibial plateau fracture.
Beware the "invisible" tibial plateau fracture on plain films!
CT image the patient's knee especially if unable to bear weight after significant blunt trauma, despite plain films.