Ischial spine
Spina ischiadica
Definition
The ischial spine refers to the sharp bony prominence which protrudes from the posterior margin of the ischium. It separates the greater sciatic notch above from the lesser sciatic notch below.
The ischial spine provides attachment to the sacrospinous ligament and some fibers of the superior gemellus muscle as they originate from the upper margin of the lesser sciatic notch. Additionally, posterior fibers of levator ani arise from the pelvic surface of the ischial spine. Furthermore, the internal pudendal vessels and nerve cross over the dorsal aspect of the ischial spine as they pass through the gluteal region to enter the perineum.
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Text written by Muhammad A. Javaid, MD, PhD © 2023 IMAIOS.
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. 1341-1345.
