An inguinal hernia is the protrusion of part of the contents of the abdomen through the inguinal region
of the abdominal wall. To understand inguinal herniae it is necessary to understand the anatomy of the inguinal canal


Surface anatomy
The inguinal ligament stretches between the anterior superior iliac spine, which is easy to see and feel, and the pubic tubercle, which is not. A skin crease runs across the lower abdomen, convex downwards, separating the abdomen from the triangle known as the mons veneris. The centre of this crease lies over the upper edge of the pubic bones. The pubic tubercles lie beneath this crease, approximately 2–3 cm either side of the mid-line. To find a pubic tubercle, put your finger on the centre of this skin crease, push
gently inwards until you feel the crest of the pubis, and then slide your finger sideways until you reach
the tubercle. You can practise this on yourself.
Muscles
Beneath the skin and subcutaneous tissue lies the aponeurosis (a word meaning a flat tendon) of the
external oblique muscle. The lower inwardly folded edge of this aponeurosis, which runs between the
anterior superior iliac spine and pubic tubercle, forms the inguinal ligament. The fibres of the aponeurosis
run parallel to the inguinal ligament in the direction taken by a hand when placed in a trouser pocket,