While performing a pelvic exenteration, the surgical oncologist notices a fractured or ruptured
boundary of the pelvic inlet. Which of the following structures is most likely damaged?
(A) Promontory of the sacrum
(B) Anterior–inferior iliac spine
© Inguinal ligament
(D) Iliac crest
(E) Arcuate pubic ligament
The answer is A. The pelvic inlet (pelvic brim) is bounded by the promontory and the
anterior border of the ala of the sacrum, the arcuate line of the ilium, the pectineal line,
the pubic crest, and the superior margin of the pubic symphysis.