Sacropelvic surface of ilium
Facies sacropelvica ossis ilium
- Related terms: Sacropelvic surface
Definition
The sacropelvic surface of ilium refers to its posteroinferior part that is situated behind and below the arcuate line. It is important to understand that the arcuate line is an oblique ridge found on the inner or medial surface of the ilium. Due to its oblique path, it divides the ilium into anterosuperior part and a posteroinferior part. The posteroinferior part is known as the sacropelvic surface.
The sacropelvic surface of ilium consists of three sub-parts: 1) an upper thickened iliac tuberosity, 2) an auricular surface located anteriorly and inferiorly to the iliac tuberosity, which articulates with the sacrum at the sacroiliac joint, and 3) a pelvic surface. It is important to note that the iliac tuberosity, auricular surface, and the antero-superior region (iliac fossa) together form the ala or wing of the ilium. On the other hand, the pelvic surface, which is part of the true pelvis, corresponds to the body of the ilium.
Several significant structures attach to the three distinct sub-parts of the sacropelvic surface of ilium:
The iliolumbar and dorsal and interosseus sacroiliac ligaments attach to the iliac tuberosity.
The ventral sacroiliac ligament attaches to the convex margin of the auricular surface.
The lower fibers of the ventral sacroiliac ligament, some fibers of the piriformis muscle, and the upper half of the obturator internus muscle attach to the pelvic surface.
References
______________________________________________________________________________
Text written by Muhammad A. Javaid, MD, PhD © 2023 IMAIOS.
Drake, R.L., Vogl, A.W. and Mitchell, A.W.M. (2009). ‘Chapter 5: Pelvis and Perineum’ in Gray’s anatomy for Students. (2nd ed.) Philadelphia PA 19103-2899: Elsevier, pp.421-424.
Standring, S. and Gray, H. (2016). ‘Chapter 80: Pelvic girdle, gluteal region and thigh’ in Gray’s anatomy The anatomical Basis of Clinical Practice. (41st ed.) New York: Elsevier, pp. 1339-1344.
