Malunion of a femoral fracture mimicking osteomyelitis in three phase bone imaging.

A case of greatly increased blood flow in the region of a fracture with malunion of the left femur, both in the flow and immediate blood pool studies during three phase bone imaging, is presented. The sluggish left femoral artery flow resulted from the greatly increased regional perfusion and is similar to the findings in acute osteomyelitis. The sluggish left femoral artery flow and greatly increased regional perfusion of the site is probably best explained as a regional "neurovascular flush" resulting from the pain caused by the malunion of the fracture and/or hyperemia in the area of the malunion responding to inflammation.