Reappraisal of the ligament of Henle (ligamentum inguinale internum mediale; Henle, 1871): a topohistological study using Korean foetuses

Ligament of Henle is one of muscle-associated connective tissues of the rectus abdominis muscle, but it has been confused with the conjoint tendon (a common aponeurosis for insertion of the inferomedial end of the obliquus internus and transversus abdominis muscles). To reconsider the inguinal connective tissue structures, we examined 20 mid-term foetuses (10 males and 10 females) at approximately 14–20 weeks of gestation (crown rump length 100–170 mm). In female horizontal sections, we consistently found the ligament of Henle as a wing-like aponeurosis extending from the lateral margin of the rectus tendon behind the superficial inguinal ring. The ligament was separated from and located behind the conjoint tendon. In all male foetuses, instead of the ligament, the conjoint tendon was evident behind the superficial ring and it winded around the posterior aspect of the spermatic cord. Therefore, although a limited number of specimens were examined, the ligament of Henle was likely to be a female-specific structure. The ligament of Henle, if developed well, may provide an arch-like structure suitable for a name “falx inguinalis” instead of the inferomedial end of the conjoint tendon. In addition, a covering fascia of the iliopsoas muscle joined the posterior wall of the inguinal canal in male, but not in female, specimens. (Folia Morphol 2013; 72; 2: 147–154)