Corpus: Obturator foramen

The foramen obturatum is a large opening in the pelvis between the pubic bone (os pubis) and the ischium (os ischii).

The foramen obturatum is formed by the two branches of the pubic bone and ischium. In men it is large and oval in shape, in women it is smaller and more triangular. The foramen is bordered by a thin, uneven bone edge, to which a thick fibrous membrane, the obturator membrane, is attached. It closes the obturate foramen, which gives the structure its name.

Above the obturate foramen, a bony groove, the obturator sulcus, can be seen on the inside of the pelvis, which runs obliquely medially and caudally. Together with parts of the obturator membrane, it forms the obturator canal. The following structures run through this canal from the pelvis to the leg:

• obturator artery
• Vena obturatoria
• obturator nerve