What landmarks would you use for safe insertion of the needle to perform lumbar puncture?

  • Lumbar puncture should be performed below the L2/3 interspace 1:
    • In adults, the solid spinal cord ends at L1 (ranges from T11 to upper L3)
    • At this level the conus medullaris continues distally as the cauda equina
    • Puncture above this level risks damaging the cord
  • The L4/5 or L3/4 interspace is usually used
  • The L4 spinous process can be estimated using Tuffier’s line:
    • An imaginary line drawn between the iliac crests 1
    • Significant anatomical variation exists between patients
  • Alternative anatomic landmarks include:
    • The tip of the scapula in line with T7 spinous process 1
    • The tip of the 10th rib in line with L1 spinous process 1
Surface landmarks for vertebrae