Epidural anatomy

Iliac crest is at L3-4, inferior scapula at T7. Structures superficial to deep: skin, fat, supraspinous ligament, interspinous ligament, ligamentum flavum, epidural space, dura mater. Spinal cord ends at L1-2. Dural sac ends at S2. Epidural space contains fat, nerve roots, arteries, and veins. Width is about 5 mm.