Conjoint tendon

The conjoint tendon is a structure formed from the conjoin tendons of the internal oblique and transversus abdominis muscles. It was formerly known as the inguinal aponeurotic falx.

It is mainly formed by the lower part of the tendon of the transversus, and is inserted into the crest of the pubis and pectineal line immediately behind the subcutaneous inguinal ring, serving to protect what would otherwise be a weak point in the abdominal wall.

It forms the roof of the inguinal canal.

Clinical significance
A direct inguinal hernia will protrude through Hesselbach's triangle, whose borders are the linea semilunaris (medially), inferior epigastric artery & vein (superolaterally), and the inguinal ligament (inferiorly). The hernia will lie medial to the spermatic cord.