Sacral stress fracture in an amateur rugby player: a case report.

BACKGROUND: Sacral stress fracture is an uncommon cause of back pain. The majority of previously reported cases have been in runners. The purpose of this case report was to describe a case of sacral stress fracture in an amateur rugby player.

CASE PRESENTATION: A healthy 18-year-old Japanese boy who was a rugby player presented with a 3-week history of lumbago. Sagittal and axial magnetic resonance imaging failed to reveal any reason for lumbago in his lumbar region. On his second presentation, 4 weeks later, his lumbago was so severe that he could not walk without a cane. A second magnetic resonance imaging revealed bone marrow edema with T1-weighted hypointensity and short inversion time inversion recovery hyperintensity at his left sacrum in coronal sections, consistent with stress fracture. Pain was relieved with rest and 1 year later he was able to return to rugby without lumbago or left buttock pain.

CONCLUSIONS: Sacral stress fracture can cause low back pain in athletes. Coronal magnetic resonance imaging appears to be an effective option for diagnosis.