Prior to performing a lumbar puncture (LP) at the bedside, the intercristal line, formed posteriorly between the superior aspect of the iliac crests, commonly serves as a landmark to identify the L4 spinous process or L4–L5 intervertebral disc. However, the vertebral level actually identified by this line may be highly variable, ranging from L1–L2 to L5–S1 [1, 2]. Given that the conus medullaris may terminate as low as the superior third of the L3 vertebral body in some patients [3–5], using the intercristal line alone prior to neuraxial procedures may place some patients at risk of cord injury.