Variation of the obturator foramen and pubic arch of the female bony pelvis.

Abstract

The purpose of this study was to determine dimensions of the obturator foramen and pubic arch of the female pelvis and to assess for variability. Ninety-six female pelvises were selected from the Cleveland Natural History Museum. The obturator foramen area, pubic arch angle, pubic ramus, pubic symphysis, and anterior urogenital triangle area were measured. Linear regression was used to evaluate independent associations. There was considerable variability of the bony architecture. The mean obturator foramen area was 12.2 +/- 2.1 cm(2) (range, 7.38-18.22 cm(2)). After controlling for height, the pubic ramus width, pubic symphysis length, and interobturator foramina distance were significantly greater in European American women compared with African American women. Obturator foramen area increased with increasing height (P = .0008) but was not associated with race. There is considerable variability in the bony architecture of the obturator foramen and pubic arch of the female pelvis. Race and height may account for some of these variabilities.