The Psoas Compartment Block for Hip Surgery: The Past, Present, and Future

Figure 1

Longitudinal sonogram of the lumbar paravertebral region showing an optimal scan for lumbar plexus block. Picture in the inset shows the orientation of the ultrasound transducer and the direction in which the needle is introduced (long axis) during an ultrasound-guided lumbar plexus block. TP: transverse process. (picture used with permission from [20].