Ligament · Pelvis

Sacrospinous ligament

Ligamentum sacrospinale

A thin triangular ligament lying in front of the sacrotuberous ligament, passing from the side of the lower sacrum and coccyx to the spine of the ischium — the small pointed projection on the inner wall of the pelvis. It is the divider between the two sciatic foramina: everything leaving the pelvis above it uses the greater foramen and everything below it the lesser. On its pelvic surface it is continuous with the coccygeus muscle, to the point that the two are often described as one structure, muscular in front and ligamentous behind. The pudendal nerve hooks around the ischial spine at its outer edge.