The obturator foramen is a large opening found on which bone region?

• A. The pelvis
• B. The skull
• C. The hip bones
• D. The radius

Answer: (C)

The obturator foramen is a feature of the hip bone (os coxae), which forms part of the pelvis. It’s the large opening on the anterior aspect of each hip bone, created by the pubis and ischium, and it’s mostly closed by a fibrous membrane with the obturator canal allowing the obturator nerve and vessels to pass into the thigh. This places it squarely in the hip bones, not in the skull or radius, and situates it within the pelvic region.