sacrospinous

Sacrospinous refers to a structure relating to the sacrum and the ischial spine, most commonly used in reference to the sacrospinous ligament of the pelvis. The sacrospinous ligament is a strong, triangular band that originates from the lateral aspects of the sacrum and coccyx and inserts on the ischial spine. It is thinner and more membranous than the nearby sacrotuberous ligament and lies in the vicinity of several pelvic and perineal structures.

Anatomically, the sacrospinous ligament forms part of the boundaries that define the sciatic foramina. It helps separate the greater sciatic foramen from the lesser sciatic foramen, working together with the sacrotuberous ligament to create these passages. The pudendal nerve and internal pudendal vessels traverse the region near the sacrospinous ligament as they exit the pelvis through the greater sciatic foramen and re-enter the perineum via the lesser sciatic foramen, passing between the sacrospinous and sacrotuberous ligaments.

Clinically, the sacrospinous ligament is notable for its use in pelvic reconstructive surgery, particularly sacrospinous ligament fixation. This procedure attaches the vaginal apex or uterus to the sacrospinous ligament to provide support in cases of pelvic organ prolapse, especially after hysterectomy. Potential complications can include buttock or thigh pain, nerve irritation, and injury to nearby neurovascular structures. The technique has several variations, with outcomes influenced by surgical approach, graft selection, and patient anatomy.