Anterior inferior iliac spine

Anterior inferior iliac spine
The obturator externus muscle (anterior inferior iliac spine visible in upper right)
Right hip-joint from the front (anterior inferior iliac spine visible at upper left)
Details
Identifiers
Latin	Spina iliaca anterior inferior
TA	A02.5.01.112
FMA	63614
Anatomical terms of bone []

The anterior inferior iliac spine (abbreviated: AIIS) is a bony eminence on the anterior border of the hip bone, or, more precisely, the wing of the ilium (i.e. the upper lateral parts of the pelvis).

The upper portion of the spine gives origin to the straight head of the rectus femoris muscle, while a teardrop-shaped lower portion gives origin to the iliofemoral ligament of the hip joint and borders the rim of the acetabulum.

Antero-medially and inferiorly to the AIIS is the iliopsoas groove, the passage for the iliopsoas muscle as it passes down to the lesser trochanter of the femur. A vague line, the inferior gluteal line, might run from the AIIS to the greater sciatic notch which delineates the inferior extent of the gluteus minimus origin.

The AIIS is formed from a separate apophysis.

Left hip-joint, opened by removing the floor of the acetabulum from within the pelvis.

Hip joint. Lateral view. Anterior inferior iliac spine visible to the left.