Differences in the Structure of the Lumbosacral Plexus

The lumbosacral plexus (analogue of the brachial plexus) can also show the differences in its formation, which manifest in different segmental participation of certain nerves. We have observed lumbosacral plexus variations in 50 human cadavers bilaterally, and the found variations are presented in the table. The lumbar plexus was visualized after the dissection of the psoas major muscle, whereas participation of T12 and L4 was observed. The presence of accessory ilioinguinal, accessory femoral, accessory obturator nerves, and various nerve interconnections are documented in the table and on the images and schemes. The formation of the visualized sacral plexus also showed multiple variations, among which multiple nerve interconnections were found (especially in its proximal section), and doubled posterior cutaneous femoral nerve, obturator nerve formation, and division variations were observed and documented. The sciatic nerve formation and its division were a good source of observed variability. The pudendal nerve was formed (depending on the type of plexus) from the S2 and S3 roots. Ignoring the importance of this anatomical variability can be the cause of surgical treatment failure.