A possible mechanism of motor blockade of high volume pericapsular nerve group (PENG) block: A cadaveric study

Ahiskalioglu et al. performed PENG block with 30 ml LA in two patients and reported quadriceps weakness in one of them [3]. [...]the mechanism of motor weakness and spread of LA during PENG is still unclear. Lateral femoral cutaneous nerve (LFCN) (L2−L3) innervates the lateral part of the thigh, FN (L2-L4), and ON (L2-L4) innervate anteromedial-distal thigh. [...]LFCN is also essential for analgesia of the hip due to surgical incision [8]. According to Giron-Arango et al., volumes greater than 20 ml could cause undesired motor block by anesthetic spreading between the pectineus and psoas to target the FN [6].