Early scintigraphic findings of occult femoral and tibial fractures in infants.

Differentiation of occult skeletal injuries from early acute osteomyelitis in infants and young children is important clinically. The Tc-99m MDP scintigraphic findings in six patients who had occult femoral or tibial fractures were reviewed. The images obtained early (at 1-4 days from the onset of symptoms) shared the common characteristic finding of a subtle but definite, generalized increased uptake of the tracer along the entire length of the injured bone. This pattern of uptake was similar regardless of the type of fracture. These were different from the focal abnormalities that have been observed in early acute osteomyelitis. In the absence of an extensive cellulitis or a vascular occlusive disease, a bone image showing a mild diffuse uniform increased uptake along the entire length of the tibia or femur in infants and young children with lower extremity pain of less than 1 week's duration should suggest the diagnosis of occult skeletal fractures.