Negative magnetic resonance imaging in three cases of anterior tibial cortex stress fractures.

Anterior mid-tibial cortex stress fractures (ATCSF) are uncommon and notoriously challenging to treat. They are termed high risk due to their predilection to prolonged recovery, nonunion and complete fracture. Early diagnosis is essential to avoid progression and reduce fracture complications. Imaging plays a key role in confirming the diagnosis. Magnetic resonance imaging (MRI) is accepted as the gold standard modality due to its high accuracy and nonionizing properties. This report describes three cases of ATCSFs in recreational athletes who had positive radiographic findings with no significant MRI changes. Two athletes had multiple striations within their tibias. Despite the radiographic findings, their severity of symptoms were low with mild or no tenderness on examination. Clinicians should be mindful that the ATCSFs may not present with typical acute stress fracture symptoms. We recommend that plain radiographs should be used as the first line investigation when suspecting ATCSFs. Clinicians should be aware that despite MRI being considered the gold standard imaging modality, we report three cases where the MRI was unremarkable, whilst radiographs and computed tomography confirmed the diagnosis. We urge clinicians to continue to use radiographs as the first line imaging modality for ATCSFs and not to directly rely on MRI. Those who opt directly for MRI may be falsely reassured causing a delay in diagnosis.