GNB
PD
PERIOSTEUM
Participants were asked to sit supine with a pillow supporting the popliteal fossa. The examined part was sterilized, and a 12 MHz linear probe (Toshiba Aplio 400 US system) was arranged. The transducer was turned sagittal at the front of the distal end of the femur. The probe was moved from medial or lateral to detect the femoral epicondyle. The genicular artery was identified near the periosteum and confirmed by PD. The genicular nerve is next to the artery. We targeted 3 genicular nerves: the superior medial, lateral, and inferior medial genicular nerves. The in-plane technique was considered and aspiration was done first to avoid intra-vascular injections [