sacrotuberous ligament

The sacrotuberous ligament (STL) is a stabilizer of the sacroiliac joint and connects the bony pelvis to the vertebral column.

Gross anatomy

The STL has a broad fan-like origin from the sacrum, coccyx, ilium and sacroiliac joint capsule. Its fibers converge to course caudally to insert into the medial ischial tuberosity and additional fibers (known as the falciform ligament) extend to the ischial ramus .

It forms a boundary of the greater and lesser sciatic foramen. Many of its fibers blend with other musculotendinous structures :

The sacrotuberous ligament is pierced by coccygeal branches of the inferior gluteal artery, the perforating cutaneous nerve, and branches of the coccygeal plexus .

Related pathology

  • pudendal nerve entrapment syndrome
    • may be secondary to sacrotuberous ligament calcification (see Case 1)