Approximately 10% of infants are born with some abnormality of the genitourinary system, and anomalies in one system are often mirrored by anomalies in another system that provide special implications in pelvic surgery.
About 75% of all iatrogenic injuries to the ureter result from gynecologic procedures, most commonly abdominal hysterectomy; risk is increased with distortions of pelvic anatomy, including adnexal masses, endometriosis, other pelvic adhesive disease, or fibroids.
An understanding of the anatomy of the female pelvis is fundamental to the knowledge base of a practicing gynecologist. Although the basic facts of anatomy and their relevance to gynecologic practice do not change with time, our understanding of specific anatomic relationships and the development of new clinical and surgical correlations continue to evolve.
The anatomy of the fundamental supporting structures of the pelvis, including the genital, urinary, and gastrointestinal viscera, are presented in this chapter. Because significant variation has developed in the names of many common anatomic structures, the terms used here reﬂect current nomenclature according to the Nomina Anatomica; other commonly accepted terms are included in parentheses (1).
Bony Pelvis The skeleton of the pelvis is formed by the sacrum and coccyx and the paired hipbones (coxal, innominate), which fuse anteriorly to form the symphysis pubis. Figure 5.1 illustrates the bony pelvis as well as its ligaments and foramina.
Sacrum and Coccyx The sacrum and coccyx are an extension of the vertebral column resulting from the five fused sacral vertebrae and the four fused coccygeal vertebrae. They are joined by a symphyseal articulation (sacrococcygeal joint), which allows some movement.
The essential features of the sacrum and coccyx are as follows: 1.
Sacral promontory—the most prominent and anterior projection of the sacrum, this is an important landmark for insertion of a laparoscope and for sacrocolpopexy. It is located just below the level of bifurcation of the common iliac arteries.
2.
Four paired anterior and posterior sacral foramina—exit sites for the anterior and posterior rami of the corresponding sacral nerves; the lateral sacral vessels also traverse the anterior foramina.
3.
Sacral hiatus—results from incomplete fusion of the posterior lamina of the fifth sacral vertebra, offering access to the sacral canal, which is clinically important for caudal anesthesia.
Laterally, the alae (“wings”) of the sacrum offer auricular surfaces that articulate with the hipbones to form synovial sacroiliac joints.
Os Coxae The paired os coxae, or hipbones, have three components: the ilium, the ischium, and the pubis. These components meet to form the acetabulum, a cup-shaped cavity that accommodates the femoral head.
Figure 5.1 The female pelvis. The pelvic bones (the innominate bone, sacrum, and coccyx) and their joints, ligaments, and foramina.
1.
Iliac crest—provides attachments to the iliac fascia, abdominal muscles, and fascia lata.
2.
Anterior superior and inferior spine—superior spine provides the point of fixation of the inguinal ligament and is clinically important as a lateral landmark for laparoscopic entry.
3.
Posterior superior and inferior spine—superior spine is the point of attachment for the sacrotuberous ligament and the posterior sacral iliac ligament.
4.
Arcuate line—marks the pelvic brim and lies between the first two segments of the sacrum.
5.
Iliopectineal eminence (linea terminalis)—the junction line of the ilium and the pubis.
6.
Iliac fossa—the smooth anterior concavity of the ilium, covered by the iliacus muscle.
1.