目的　为侧后路经皮L5~S1节段椎间孔入路椎间孔镜下髓核摘除术提供解剖学依据。 方法   成人脊柱标本10具，左右共20侧，观测椎间孔镜侧后方入路时穿刺针与髂嵴、S1上关节突、L5出口根、硬膜囊以及椎体动静脉等结构的毗邻关系； 并测量各型突出的穿刺角度范围。 结果   所有数据经左右配对t 检验，差异均无统计学意义（P＞0.05）。走行于S1上关节突根部的结构有L5脊神经后内侧支和L5节段动脉背侧支的降支及其伴行静脉。髂嵴最高点至脊柱中线的垂直距离为（9.25±0.47）cm，髂嵴最高点与上关节突前缘的冠状面夹角为（11.10±1.17）°，冠状面L5横突与髂嵴的距离为（10.78±0.81）mm，中央型、侧旁型和极外侧型进针角度分别为（83.00±1.92）°、（32.15±1.63）°~（62.60±1.70）°和（11.75±1.16）°，L5出口根、 硬膜囊至上关节突定位点的距离分别为（8.30±0.87）mm和（17.29±1.06）mm，L5出口根下缘至椎间孔下缘距离为（5.84±0.67）mm，上关节突的高度为（11.31±0.96）mm，S1上关节突前后缘总长为（17.41±0.98）mm。  结论    侧后路经皮L5~S1节段椎间孔入路的穿刺定位较复杂，要求术者有较强的解剖学知识和空间想象力。

Objective    Provide objective anatomical basis for postolateral percutaneous L5~S1 transforaminal endoscopic discectomy.   Method   To the adjacent relationship among the needle, the iliac crest, the superior S1  articular process, the L5 efferent roots, the dura, and the vertebral vessels were observed and measured; various types of protrusion of puncture angle range in 10 adult spinal specimens(20 sides) were also measured when TESSYS was placed into the L5~S1 foramen.   Results   All data have not shown statistical difference by paired t test (P>0.05). There were L5 posterior medial nerve branches, descending branches of dorsal branches of L5 segmental arteries and veins going around the roots of S1 superior facet. The vertical distance from highest point of iliac crests to the midline of spine was (9.25±0.47) cm, the angle between highest point of iliac crests and leading edge of superior facets on the coronal plane was (11.10±1.17) °, the distance between L5 transverse processes and iliac crests on the coronal plane was (10.78±0.81) mm, central protrusion angle of the needle was (83.00±1.92) °, lateral protrusion angle of the needle was (32.15±1.63) °~( 62.60±1.70) °, extreme lateral protrusion angle of the needle was (11.75±1.16) °, the anchor points of superior facets to L5 exiting roots and the dura was (8.30±0.87) mm and (17.29±1.06) mm, respectively, inferior margin of L5 exiting roots to lower edge of foramen was (5.84±0.67) mm, the height of superior facets was (11.31±0.96) mm, the length of S1 superior facets was ( 17.41±0.98) mm.   Conclusions   The puncture and location of postolateral percutaneous L5~S1  transforaminal approach is complex than other lumbar segments, which requires that physicians have a solid knowledge of anatomy and excellent spatial visualization.