Supramalleolar fatigue fractures of the tibia

The objective of this paper is to describe fatigue fractures in the supramalleolar area of the tibia. The spectrum of imaging findings in 14 cases is presented, with emphasis on plain film radiographic findings.

Fourteen patients with fatigue fractures in the supramalleolar area of the distal tibia were seen in a 6-year period. The 13 men and 1 woman had an age range from 14 to 64 years (mean 30 years). These patients had no underlying conditions that would predispose them to fractures. Sequential plain film radiographs and other special imaging studies (technetium-99m scans and computed tomography) were retrospectively reviewed.

Initial plain film radiographs showed a horizontal linear band of increased density in only 2 cases, a subtle cortical bulge in 5 cases, a focal "graying" of the cortex in 2 cases, a single layer periosteal reaction in 1 case, and no abnormality in the final 4 cases. Technetium-99m scans were done in 11 cases and showed focal areas of increased uptake in all 11. These areas of increased uptake were vertically orientated in 10. One patient had computed tomography showing cortical thickening around a linear lucency. The spectrum of imaging findings is similar to that seen in fatigue fractures in more common locations. Supramalleolar fatigue fractures should be suspected in patients who have pain in the distal tibia even when initial plain film radiographs are normal. When initial radiographs are normal, technetium-99m scans can confirm the diagnosis.