An Atraumatic Sacral Fracture with Lumbosacral Radiculopathy Complicating the Early Postpartum Period: A Case Report.

BACKGROUND Sacral stress fractures are rare complications of pregnancy and the early postpartum. Of these, few present with lumbosacral radiculopathy. We report the first Australian case of a young multiparous woman who sustained an atraumatic, fatigue sacral fracture with associated radiculopathy. We highlight the diagnostic process and chronic management of this case, particularly in relation to a future pregnancy. CASE REPORT A 26-year-old multiparous Caucasian female presented with worsening lumbosacral back pain and radicular symptoms following the rapid and spontaneous vaginal delivery of her second infant. Her pregnancy was unremarkable and she had no personal risk factors for osteoporosis. A magnetic resonance imaging (MRI) scan confirmed the diagnosis of a right S1 vertebral fracture. Bone densitometry and fasting bone metabolic testing excluded pregnancy-associated osteoporosis. She was managed conservatively with intermittent bed rest, regular physiotherapy and multimodal analgesia. During a future pregnancy, she experienced a severe exacerbation of her lumbosacral radiculopathy requiring hospital admission, up-titration of her analgesia and a right S1 epidural injection. She subsequently underwent an elective caesarean section and has since benefitted from regular hydrotherapy. CONCLUSIONS Lumbosacral radiculopathy in the absence of trauma during pregnancy or the early postpartum should prompt consideration of an underlying atraumatic, fatigue sacral fracture. Such fractures may result from the abnormal biomechanical loading of the sacrum during rapid vaginal deliveries and are most effectively diagnosed by MRI. Conservative management strategies involving physiotherapy and multimodal analgesia are recommended. Future pregnancies may exacerbate radicular symptoms. Such patients may subsequently benefit from elective caesarean section deliveries and hydrotherapy.