Subarachnoid space into the needle site

Clinical location of ascending lumbar puncture: the puncture point of lumbar puncture is generally at the line of the two posterior upper iliac poles, and the needle is injected in the gap between L3 and L4 or L4 and L5. 2. The structure that the needle passes through in turn from shallow to deep: the puncture needle head should pass through the skin, subcutaneous tissue, supraspinous ligament, interspinous ligament between spinous processes, ligamentum flavum and epidural space in turn