The inguinal ligament, also known as Poupart ligament or the fallopian ligament, is a fibrous band extending from the anterior superior iliac spine to the pubic tubercle. It is an important anatomical landmark and denotes the transition of the pelvis to the lower limb.

Gross anatomy

The inguinal ligament is formed by the lower border of the aponeurosis of the external oblique muscle, which is thickened and folded on itself. Its lateral half runs obliquely, while the medial half is almost horizontal.

Attachments

The inguinal ligament arises from the anterior superior iliac spine and attaches to the pubic tubercle, although there are some fibres that attach elsewhere as extensions or reflections of the inguinal ligament:

• some fibres pass posteriorly to attach to the superior pubic ramus forming the lacunar ligament (of Gimbernat)

• fibres that run with the lacunar ligament continue to pass more medialward to attach to the pecten pubis, forming pectineal ligament (of Cooper)

• superior fibres run past the pubic tubercle to fuse with those of the contralateral external oblique aponeurosis, forming the reflected inguinal ligament

The upper surface of the ligament gives origin to the external spermatic fascia from its medial part, internal oblique muscle from the lateral two-thirds and transversus abdominis muscle from its lateral one-third.

The ligament is continuous with the fascia lata of the thigh and the upper grooved surface forms the floor of the inguinal canal.

Relations

The retroinguinal passage or subinguinal space is formed deep to the inguinal ligament and contains a number of structures as they pass from the pelvis to the lower limb:

• iliopsoas muscle

• common femoral artery and vein

• femoral nerve

• lymphatic channels draining inguinal lymph nodes

• deep circumflex iliac artery (laterally)

History and etymology

It is named after Francois Poupart, a French surgeon (1661-1709) who accurately described the inguinal ligament in the "Histoire de l’Académie Royale des Sciences de Paris" in 1705 ⁵.

However, like many eponyms, it was actually first described 150 years earlier by Gabriele Falloppio (also known by his Latin name Fallopius), an Italian anatomist (1523-1562), after whom the fallopian tube and fallopian (facial nerve) canal are also named ^4,5.