The round ligament of the uterus: Questioning its distal insertion.

PURPOSE: Classically, the round ligament of the uterus (RLU) attaches distally in the ipsilateral labia majora. This attachment has rarely been described in adults. That is why we have performed an anatomical study focused on this distal ending.

PATIENTS: We performed in 2015 the cadaveric dissection of 19 RLU.

METHODS: In all cases, the RLU was individualized on its entire length from its uterine origin to the inguinal canal. Then this canal was open from its internal orifice to its external orifice. We described the distal attachment of the RLU according four areas: before the internal inguinal ring, after the external inguinal ring, under the pubic bone and in labia majora.

RESULTS: We found 3 types of distal attachments with first an attachment after the external inguinal ring in more than half of cases (52.6%). Then, before the internal inguinal ring (26.3%) and under the pubic bone (22.1%). No RLU was found inlabia majora. However, the proximal attachment seems constant at the antero-superior face of uterus, near the tubo-uterine junction like its pelvic path under the broad ligament.

CONCLUSION: In adult, the RLU is a structure, which begins at the cranio-ventral part of the uterine bottom near the tubo-uterine junction. Then it passes under the broad ligament and reaches the inguinal canal, that it crosses in more half of cases. However, 3 distal attachment areas have been identified but never in the labia majora. Indeed, some anatomical information available in anatomical treaties seems not correct and should be amended.