The inguinal ligament and its lateral attachments: correcting an anatomical error.

The inguinal portions of the internal oblique and transversus abdominis muscles are generally described as arising from the inguinal ligament. Previous authors have shown that this description is incorrect. A new dissection study in 15 lightly embalmed cadavers confirms that in reality the inguinal portions of these muscles arise from a thickened strip of ilipsoas fascia that forms the superolateral part of the ilio-pectineal arch. Details are given of a new dissection technique that fully exposes the deep aspect of the inguinal ligament, without disrupting its continuity. The historical background of the persistent textbook error is explored. It originated at a time when there was widespread descriptive and semantic confusion regarding the structure now known as the inguinal ligament.