Longitudinal tibial fatigue fracture: an uncommon stress fracture with characteristic features.

PURPOSE

The author reports three cases of longitudinal tibial fatigue fractures, reviews the literature, and discusses characteristic features that suggest the diagnosis may be made by bone scintigraphy.

METHODS

Radiographs and two- or three-phase bone scintigraphs with Tc-99m MDP were obtained in three runners who had exercise-related leg pain and whose clinical symptoms suggested either stress fractures or shin splints. The literature was reviewed and previously reported scintigraphic findings were compared with those seen in these three cases.

RESULTS

In contrast to the focal, elliptical, cortex-based abnormal activity usually seen in the upper or middle tibia in patients with tibial stress fractures, all three patients had a long area of abnormal diffusely increased tibial activity that extended from the tibiotalar region proximally. This finding was seen on the 3-hour delayed static images of all three patients and was suggested on the blood-pool (tissue phase) images. The literature also contained reports of these same scan characteristics. Radiographs subsequently disclosed a longitudinal tibial stress fracture in one patient, computed tomography was positive in the second patient, and findings of clinical follow-up and radiographs were consistent with this diagnosis in the third patient.

CONCLUSION

In the appropriate clinical setting and with normal or nondiagnostic radiographs, the presence of a long area of diffusely increased activity in the distal tibia extending proximally from the tibiotalar junction is indicative of a longitudinal fatigue fracture.