The iliac fossa is a shallow fossa located on the inner surface of the wing of the ilium, which is the lateral wall of the greater pelvis, and is divided into the left and right iliac fossae on either side of the pelvis, between the posterior peritoneum and the iliopsoas muscle.
The ilium is divided into two parts, the body of the ilium and the wing of the ilium. The anterior part of the ilium is the iliac wing, and the posterior part of the ilium is the iliac body. Below them protrudes what are each called the anterior inferior iliac spine and the posterior inferior iliac spine. Below the posterior inferior iliac spine is the great sciatic notch. The smoother depression on the inner surface of the iliac wing is called the iliac fossa.
The lower border of the iliac fossa protrudes into the arcuate line, and above the arcuate line is the auricular surface, which forms the sacroiliac joint with the sacrum. The ilium, together with the surrounding pubic bone and sciatic bone, forms the pelvis, whose main function is to support and protect the body.
The iliac fossa is a space made up of loose connective tissue, which is rich in blood vessels and nerves, such as the external iliac artery and external iliac vein, spermatic artery and vein, iliac fossa lymph nodes, and genitofemoral nerve.