Saleh H A M, El-fark M M O, Abdel-Hamid G A
Department of Anatomy, Faculty of Medicine, King Abdulaziz University, P.O. Box 80316, Jeddah 21589, Saudi Arabia.
Folia Morphol (Warsz). 2009 Nov;68(4):256-9.
The sciatic nerve (SN) originates from the L4-S3 roots in the form of two nerve trunks: the tibial nerve (TN) and the common peroneal nerve (CPN). The TN and CPN are encompassed by a single epineural sheath and eventually separate (divide) in the popliteal fossa. This division of the SN occurs at a variable level above the knee and may account for frequent failures reported with the popliteal block. We studied the level of division of the SN in the popliteal fossa and its relationship to the common epineural sheath of the SN. The level of division of the SN sheath into TN and CPN above the knee was measured in 30 cadaver specimens. The SN was invariably formed of independent trunks (TN and CPN) encompassed in one common epineural sheath. The SN divided at a distance range of 50 to 180 mm above the popliteal fossa crease. The present findings suggest that the TN and CPN leave the common SN sheath at variable distances from the popliteal crease. This finding and the relationship of the TN and CPN sheaths may have significant implications for popliteal nerve block.
坐骨神经（SN）以两条神经干的形式起源于L4 - S3神经根：胫神经（TN）和腓总神经（CPN）。TN和CPN被包裹在一个单一的神经外膜鞘内，最终在腘窝处分开。SN的这种分开发生在膝关节上方的不同水平，这可能是腘窝阻滞报道中频繁失败的原因。我们研究了SN在腘窝处的分开水平及其与SN共同神经外膜鞘的关系。在30个尸体标本中测量了SN鞘在膝关节上方分为TN和CPN的水平。SN总是由包裹在一个共同神经外膜鞘内的独立神经干（TN和CPN）组成。SN在腘窝皱襞上方50至180毫米的距离范围内分开。目前的研究结果表明，TN和CPN在距腘窝皱襞不同距离处离开共同的SN鞘。这一发现以及TN和CPN鞘的关系可能对腘窝神经阻滞有重要意义。
