About one in ten Australians who have lumbar X-rays has a lumbosacral transitional vertebra, and the reporting radiologist names it in fewer than a third of cases. In a minority of those people the transitional articulation is a pain generator, and in some of those surgery directed at it is the treatment. The literature on that surgery is small: retrospective series from a handful of centres, case reports and reviews, with no randomised trial.

This guide sets out, for neurosurgeons and orthopaedic spine surgeons, what that literature supports and how it applies in Australian practice: the Castellvi and Jenkins classifications and the difference between them at the low end; vertebral enumeration and wrong-level surgery; clinical assessment and imaging; diagnostic blocks; patient selection and the factors associated with failure; the choice between resection and fusion by anatomical type; the published operative techniques for each; complications; postoperative care and follow-up; the Medicare items and the funding pathway; and the state of the evidence. Appendices give illustrative cases, points for the consent discussion and a glossary. Two further chapters set out what patients report and what a referral from a clinician who has followed the companion guides will contain.

Every clinical statement is referenced to the published evidence, and the notes at the end say what could and could not be verified.