external inguinal ring
Last reviewed 08/2021
The superficial or external inguinal ring is the distal extremity of the inguinal canal. It is V-shaped with the apex of the V pointing superolaterally. It is formed by the divergence of the external oblique aponeurosis.
The aponeurosis has two crura:
- medial: attached to the pubic crest near the symphysis
- lateral: attached to the pubic tubercle
Between these two crura at the apex of the ring, intercrural fibres run perpendicularly to provide reinforcement.
In addition to the two main crura, there is a posterior crus. This is a lesser continuation of the inguinal ligament posterior to the cord from the pubic tubercle. This extends posterior to the medial crus into the rectus sheath. Within the rectus sheath, these fibres merge with those originating from the contralateral side.