Lateral meniscus

The lateral meniscus (meniscus lateralis; external semilunar fibrocartilage) is nearly circular and covers a larger portion of the articular surface than the medial one. It is grooved laterally for the tendon of the Popliteus, which separates it from the fibular collateral ligament.

Its anterior end is attached in front of the intercondyloid eminence of the tibia, lateral to, and behind, the anterior cruciate ligament, with which it blends; the posterior end is attached behind the intercondyloid eminence of the tibia and in front of the posterior end of the medial meniscus.

The anterior attachment of the lateral meniscus is twisted on itself so that its free margin looks backward and upward, its anterior end resting on a sloping shelf of bone on the front of the lateral process of the intercondyloid eminence.

Close to its posterior attachment it sends off a strong fasciculus, the ligament of Wrisberg, which passes upward and medialward, to be inserted into the medial condyle of the femur, immediately behind the attachment of the posterior cruciate ligament.

Occasionally a small fasciculus passes forward to be inserted into the lateral part of the anterior cruciate ligament. The lateral meniscus gives off from its anterior convex margin a fasciculus which forms the transverse ligament.

Radiological anatomy:

The lateral meniscus can be divided into the anterior horn, body, and posterior horn.

The posterior horn of the lateral meniscus is particularly notable for its relationship with the popliteus tendon. The popliteus tendon passes obliquely through the posterior half of the meniscus, creating a tunnel-like structure with distinct medial and lateral walls, a superior attachment (roof), and an inferior attachment (floor). These anatomical features are well-visualized on double-contrast knee arthrograms, aiding in the diagnosis of meniscal injuries.

The attachment areas of the lateral meniscus are also significant. The anterior horn fibers extend to the anterior cruciate ligament (ACL) and intermingle with its fibers, while the posterior horn fibers are divided into anterolateral and posteromedial crura, attaching to the posterior aspect of the lateral and medial intercondylar tubercles, respectively. These attachments form the posterior margin of the ACL attachment area.

Additionally, the popliteomeniscal fascicles and the lateral meniscotibial ligament are key structures associated with the lateral meniscus. The popliteomeniscal fascicles attach to the posterolateral capsule and the meniscofemoral ligaments, providing structural support and contributing to the meniscus's mobility and stability.