The interfoveolar ligament, seen from in front. (Inguinal aponeurotic falx labeled at lower left.)
|Latin||falx inguinalis, tendo conjunctivus|
The conjoint tendon (previously known as the inguinal aponeurotic falx) is a structure formed from the lower part of the common aponeurosis of the internal oblique muscle and the transversus abdominis as it inserts into the crest of the pubis and pectineal line immediately behind the superficial inguinal ring. It is usually conjoint with the tendon of the internal oblique muscle, but they may be separate as well. It forms the medial part of the posterior wall of the inguinal canal.
A direct inguinal hernia will protrude through Hesselbach's triangle, whose borders are the rectus abdominis (medially), inferior epigastric artery and vein (superolaterally), and the inguinal ligament (inferiorly). The hernia will lie medial to the inferior epigastric artery. This is in contrast to an indirect inguinal hernia, which will protrude laterally to the inferior epigastric artery and is most commonly due to an embryological defect in the closure of the deep inguinal ring.