Fig. 4.

Topography of the rectus-origin-sparing approach (red line) between the iliopsoas (IP) and rectus femoris (R). The first branch of the femoral nerve (yellow arrow) reaches the undersurface of the rectus muscle at the level of the lesser trochanter (Less troch). S = sartorius muscle, ASIS (yellow pin) = anterior superior iliac spine, and AIIS (blue dot) = origin of the direct rectus tendon on the anterior inferior iliac spine. The white circle indicates the position of the joint. (Courtesy of Karl Grob, MD, HCARE KSSG St. Gallen, Switzerland.)