The Pelvis

Abstract

The pelvis is divided into the greater (false) and the lesser (true) pelvis by an approximately circular opening described variously as the superior aperture, brim, or inlet which is outlined by the pro- montary of the sacrum (upper anterior border of the body of the first sacral vertebra), the ala of the sacrum, the terminal (arcuate) line of the ilium, the iliopubic eminence, the pectineal line, the pubic crest and the upper border of the symphysis pubis (figure 101). The greater pelvis consists largely of the ala of the ilium on each side where it extends upwards and laterally above the superior aperture. Actually the greater pelvis forms the lower lateral walls of the abdominal cavity. It is proposed therefore to use the word pelvis to describe the lesser pelvis unless further definition is required.