Iliac crest - e-Anatomy - IMAIOS

Description

The iliac crest is a wide, convex ridge that forms the upper border of the iliac part of the hip bone. It demarcates the lower boundary of the flank region. Extending from the anterior superior iliac spine (ASIS) to the posterior superior iliac spine (PSIS), it holds significant anatomical attachments such as the inguinal ligament and sartorius muscle.The highest point of the iliac crest lies slightly behind its midpoint, between the third and fourth lumbar vertebral spines. It serves as a landmark for lumbar puncture procedures.Morphologically, the iliac crest can be divided into two sections: ventral (anterior 2/3rd) and dorsal (posterior 1/3rd).A.      The VENTRAL SEGMENT further consists of outer and inner lips, with an intermediate zone in between.The outer lip provides attachment to the fascia lata along its entire extent. Muscles attached to the outer lip, from anterior to posterior, include tensor fascia lata, external oblique, and latissimus dorsi. Notably, a prominent bony iliac tubercle protrudes outward from the outer lip, situated slightly behind the anterior superior iliac spine, marking the origin of the iliotibial tract.The intermediate zone is the site of attachment for the internal oblique muscleThe inner lip provides attachment for the transversus abdominus muscle, as well as the transversalis and iliacus fascia anteriorly, and the quadratus lumborum and thoracolumbar fascia posteriorly.B.      The DORSAL SEGMENT of the iliac crest exhibits lateral and medial slopes, separated by a ridge.The lateral slope gives rise to the gluteus maximus muscleThe medial slope is the origin site for the erector spinae muscle, as well as the interosseus and dorsal sacroiliac ligaments.