Lateral meniscus

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Sagittal view of the knee joint showing the patellofemoral and tibiofemoral joints.

The lateral meniscus of the knee joint is a crescent shaped, fibrocartilaginous structure which, along with the medial meniscus, serves as an intermediary component of the tibiofemoral joint of the knee. The lateral meniscus is located within the capsule of the knee joint, specifically between the lateral condyle of the femur and tibia.

The lateral meniscus has a thick, convex peripheral border and a thin concave central border, however is slightly smaller but more circular in shape than the medial meniscus (it forms about four-fifths of a circle compared to more semicircular shape of the medial meniscus).

The lateral meniscus is composed of three parts: an anterior horn/root, body and posterior horn/root.

• The anterior horn attaches to the anteromedial aspect of the lateral intercondylar eminence of the tibial plateau, as well the anterior horn of the medial meniscus via the transverse ligament of the knee.
• The inferior border of body of the lateral meniscus is attached to the tibial plateau via the lateral meniscotibial ligament (a.k.a. lateral coronary ligament of the knee joint).
• The posterior horn attaches slightly posteromedial to the lateral intercondylar eminence of the tibial plateau. 

Both menisci of the knee joint primarily serve to improve congruency between adjacent femoral and tibial articular surfaces; they achieve this by augmenting the surface area of the relatively flat proximal articular surface of tibia (tibial plateau), making it broader/deeper and better able to accommodate the rounded distal articular surfaces of the femur. This results in a better distrubition of load transmitted from the femur to the tibia and protection of the articular surfaces of the femur and tibia.