A lumbosacral transitional vertebra is a congenital variant in which the lowest lumbar vertebra articulates or fuses with the sacrum. When that variant becomes painful, the condition is known as Bertolotti syndrome. Low back pain is the fifth most common reason for presentation to Australian emergency departments, and Australian emergency guidance directs clinicians away from imaging and opioids for non-specific low back pain. That pathway suits most patients, including the patient with Bertolotti syndrome in a flare. Its one defect for this condition is the label it leaves behind: non-specific low back pain, in a patient whose pain has a structural cause.

This guide is for emergency physicians, registrars, nurses and physiotherapists working in Australian emergency departments. It covers screening for serious pathology, the presentation of a flare, the four history questions that change the discharge letter, hip pain as a presenting feature, when existing imaging answers the question and when new imaging does not, analgesia, admission, and what the discharge letter should say. References are numbered in Vancouver style, with notes on verification.