Lateral crus of superficial inguinal ring

The lateral crus of superficial inguinal ring is the lateral tendinous margin of the superficial inguinal ring formed by fibres of the external oblique aponeurosis. It extends inferolaterally to attach to the pubic tubercle and forms the stronger, more welldefined lateral boundary of the superficial inguinal ring. Together with the medial crus, it encloses the triangular opening that constitutes the external opening of the inguinal canal.

Anatomically, the lateral crus lies lateral to the spermatic cord in males or the round ligament of the uterus in females as these structures emerge from the superficial inguinal ring. The crura are connected superiorly by intercrural fibres, which reinforce the margins of the ring and help prevent excessive separation during increases in intraabdominal pressure.

Clinical correlate

Clinically, the lateral crus is an important anatomical landmark in groin examination and hernia surgery. Indirect inguinal hernias emerge through the superficial inguinal ring after traversing the inguinal canal, passing between the medial and lateral crura. Weakness or widening of the ring may predispose to herniation.