Figure 2.

(a) Anatomical landmarks for the dorsal approach to the FN. (b) Cross-sectional anatomical image of the dorsal approach at the seventh lumbar vertebrae level (caudal view). The left and right femoral nerves (FN) (arrows) are visualisation embedded on the sublumbar muscles. (c) Transverse ultrasonographic image of the FN (arrowhead) at the dorsal approach. (d) Corresponding close cross-sectional anatomic image. Lat = lateral, Cr = cranial, Cd = caudal, IL = crest of ilium, GT = greater trochanter, IS = ischial tuber, IPM = iliopsoas muscle, L6 = sixth lumbar dorsal process, L7 = seventh lumbar dorsal process, 1 = quadratus lumborum muscle, 2 = psoas major muscle, 3 = iliacus muscle, 4 = seventh lumbar vertebrae transverse process, 5 = spinal cord, 6 = epaxial muscles, 7 = wing of ilium, 8 = iliac veins, 9 = external and internal iliac arteries, 10 = colon, 11 = urinary bladder, 12 = sartorius muscle, 13 = rectus abdomini