What is the Lacunar Ligament?

The lacunar ligament, also known as Gimbernat's ligament, is a significant anatomical structure in the groin region. It is a triangular or half-moon shaped, shelf-like ligament that plays a crucial role in the architecture of the femoral canal, particularly influencing the potential for certain types of hernias.

Anatomical Features and Formation

This robust ligament is an extension of the inguinal ligament, specifically formed by its medial fibers. It also incorporates fibers from the fascia lata of the thigh, creating a strong, unyielding band. Its dimensions are notable, measuring approximately 2 cm from its base to its apex.

Key characteristics of the lacunar ligament include:

• Shape: Distinctively triangular or half-moon shaped, presenting a shelf-like appearance.
• Origin: Derived from the most medial fibers of the inguinal ligament.
• Composition: Reinforced by fibers extending from the fascia lata, the deep fascia of the thigh.
• Dimensions: Typically measures about 2 cm from its broadest point (base) to its narrowest point (apex).
• Location: Situated at the medial end of the inguinal ligament, where it inserts into the pubic bone (specifically, the pectineal line of the pubis).

Role in Groin Anatomy

The lacunar ligament is integral to the boundaries of the femoral ring, an opening that leads into the femoral canal. It forms the medial boundary of this ring, while the inguinal ligament forms the anterior boundary, the pectineal line of the pubis forms the posterior boundary, and the femoral vein forms the lateral boundary.

This anatomical arrangement is critical due to its unyielding nature. Unlike other structures that might stretch or deform, the lacunar ligament maintains its shape and rigidity.

Clinical Significance

The primary clinical importance of the lacunar ligament lies in its association with femoral hernias.

• Hernia Constriction: When abdominal contents protrude through the femoral ring, they form a femoral hernia. The sharp, rigid edge of the lacunar ligament often forms the medial border of the hernia sac's neck. Because the ligament is unyielding, it can tightly constrict the hernia, making femoral hernias more prone to strangulation (where the blood supply to the herniated tissue is cut off) compared to other types of hernias. This risk necessitates prompt surgical intervention for femoral hernias.
• Surgical Landmark: Due to its consistent anatomical position, the lacunar ligament serves as an important landmark for surgeons performing groin hernia repairs or other procedures in the region.

In summary, the lacunar ligament is a small yet remarkably significant anatomical structure, defined by its unique shape, formation from surrounding ligaments and fascia, precise dimensions, and critical role in the integrity of the femoral region, particularly in the context of femoral hernias.