obturator foramen obturator foramen the obturator foramen (latin foramen obturatum) is the large opening created by the ischium and pubis bones of the pelvis through which nerves and blood vessels pass. obturator foramenpelvis. obturator foramen is 7.symphysis pubis exposed by a coronal section. obturator canal labelled at center.detailsidentifierslatinforamen obturatumta98a02.5.01.008ta21314fma16999anatomical terms of bone structure it is bounded by a thin, uneven margin, to which a strong membrane is attached, and presents, superiorly, a deep groove, the obturator groove, which runs from the pelvis obliquely medialward and downward. this groove is converted into the obturator canal by a ligamentous band, a specialized part of the obturator membrane, attached to two tubercles: one, the posterior obturator tubercle, on the medial border of the ischium, just in front of the acetabular notch the other, the anterior obturator tubercle, on the obturator crest of the superior ramus of the pubis variation reflecting the overall sex differences between male and female pelvises, the obturator foramina are oval in the male and wider and more triangular in the female. additionally, unilateral pelvis hypoplasia can cause differences in size between the obturator foramina, and there are even rare reports of individual pelvises featuring a double obturator foramen in one of the hip bones. function through the canal the obturator artery, obturator vein and obturator nerve pass out of the pelvis.