Pelvic outlet

Boundaries

• anteriorly: the pubic arch
• laterally: the ischial tuberosities
• posterolaterally: the inferior margin of the sacrotuberous ligament
• posteriorly: the anterior border of the middle of the coccyx.

  Notches

• one in front, the pubic arch, formed by the convergence of the inferior rami of the ischium and pubis on either side.
• The other notches, one on either side, are formed by the sacrum and coccyx behind, the ischium in front, and the ilium above; they are called the sciatic notches; in the natural state they are converted into foramina by the sacrotuberous and sacrospinous ligaments.

  In situ

• in front, by the pubic arcuate ligament and the inferior rami of the pubes and ischia
• laterally, by the ischial tuberosities
• behind, by the sacrotuberous ligaments and the tip of the coccyx.

  Additional images