Sono-anatomy of the pelvic limb. The saphenous nerve (SN) can be visualized as a hyperechoic round structure, within the same fascial plane (medial femoral fascia) of other hyperechoic round structures (collapsed femoral artery and vein due to absence of blood flow). These structures were caudally to the vastus medialis muscle (VM m.), medially and caudally to the femur (F), cranially and medially to the adductor (A m.) and semimembranosus (SM m.) muscles, medially to the pectineus muscle (P m.) and immediately below the sartorius muscle (S m.). MFF: Medial Femoral Fascia; M: Medial; L: Lateral; Cr: Cranial; Cd: Caudal.