UMEM Educational Pearls

Question

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"I was kicked in the inside of my knee while it was straight (extended). Look at the x-ray and tell me if its bad"

Answer

The arcuate sign

Avulsion fracture of the styloid of the proximal fibula. The fragment is usually small (less than 1 cm) and displaced superiorly and medially. This fracture pattern is pathognomonic for posterolateral corner (PLC) injury.

 

Treatment in ED is knee immobilization in full extension. Refer to orthopedics for PCL reconstruction.