中文摘要：

目的观察椎管内腰骶神经前后根的解剖结构,为临床应用健侧腰骶神经根移位重建脑卒中偏瘫下肢运动功能提供解剖学基础。方法新鲜成人尸体标本6具,腰骶部后正中切口,显露脊髓圆锥及马尾。解剖测量L2-S1脊神经根长度、前根直径,在高倍显微镜下计数有髓神经纤维数目,并模拟神经根前根移位吻合。结果 L2-S1神经根在椎管内的长度自上而下逐渐变长,其长度分别为（7.57±0.82）、（9.12±1.04）、（11.56±1.27）、（12.75±1.33）和（13.87±1.56）cm。L2-S1神经根前根直径分别为（1.10±0.10）、（1.32±0.16）、（1.24±0.12）、（1.42±0.14）和（1.52±0.21）mm。L2-S1神经根前根有髓神经纤维数目分别为（8051±898）、（10253±1035）、（8684±1168）、（9638±1446）和（9347±1322）根。标本中模拟神经根移位,L2-S1双侧相同或相邻神经根前根均能达到无张力直接吻合。结论健侧L2-S1神经根前根有望成为新的动力源神经移位修复脑卒中后偏瘫下肢运动功能。

英文摘要：

Objective Observe the anatomic structure of intraspinal anterior and posterior lumbosacral roots to provide anatomic basis for clinical application of normal lumbosacral nerve roots transferring in lower extremity motor functionrestoration in hemiplegic stoke. Methods Posterior lumbosacral midline incisions were made on both sides of 6 adult cadaveric specimens; conus medullaris and cauda equine were exposed; the length of L2-S1 spinal nerve roots and diameter of anterior roots were measured; the amount of myelinated nerve fibers was counted under a high-powered microscope, and anterior nerve roots transferring was simulated. Results The length of L2-S1 spinal nerve anterior roots gradually increased from top- down in spinal canal, being （7.57±0.82）, （9.12±1.04）, （11.56± 1.27）, （12.75±1.33） and （13.87± 1.56） cm, respectively. The diameter was （1.10±0.10）, （1.32±0.16）, （1.24±0.12）, （1.42±0.14） and （1.52±0.21） mm. The amount of myelinated nerve fibers was （8051±898）, （10253±1035）, （8684±1168）, （9638± 1446） and （9347± 1322）. The same or adjacent segments of bilateral anterior nerve roots could be directly anastomosed without tension in the simulated transferring on the cadaveric specimens. Conclusion Contralateral L2-S1 spinal nerve anterior roots can be used as new donor nerves to repair lower extremity motor function in hemiplegic stoke.