Papers of the Week

We read with interest the article by Nielson et al. describing the iliopsoas plane block (IPB), targeting the sensory hip articular branches of the femoral nerve without causing motor blockade. We applaud this group on the development of this clinically relevant technique. The authors also discuss the pericapsular nerve group (PENG) block as a reasonable alternative. In our clinical practice we have utilized PENG blocks extensively and have observed excellent analgesia for various hip surgeries. We have previously reported several cases of inadvertent motor blockade using the PENG block in patients undergoing total hip arthroplasty. Possible explanations of inadvertent motor blockade include technical issues, specifically injecting local anesthetic superficial to the iliopsoas plane or medial to the psoas tendon and performing the block postoperatively within disrupted tissue planes. Subsequent to this publication we have had additional cases of quadriceps motor weakness despite the PENG block being performed by experienced staff and taking precautions outlined by Girón-Arango et al. This has led to reduced usage of the PENG block in our institution. We suggest that randomized controlled clinical trials be performed to further assess the effectiveness and adverse effects of the PENG block.