Structure
The lateral meniscus of the knee joint is a flat, intra-articular, crescentic fibrocartilaginous band that attaches to the intercondylar eminence of the tibia via its anterior and posterior horns. The lateral meniscus forms four fifths of a circle and covers a larger area over the articular surface of the tibia than that of the medial meniscus.
The outer, attached borders of the menisci are thick and convex, while their free inner borders are thin and concave. The outer margins are vascularized, while the inner free margins are avascular. Thus, peripheral tears are more likely to heal compared to tears on the inner margins. The horns of the menisci are richly innervated, while the central parts are devoid of innervation.
Related parts of the anatomy
Anatomical Relations
The anterior horn of the lateral meniscus lies between the intercondylar eminence (posteriorly) and the anterior cruciate ligament (anteriorly). The posterior horn lies between the intercondylar eminence (anteriorly) and the posterior horn of the medial meniscus (posteriorly). The lateral meniscus is grooved and attached posterolaterally to the popliteal tendon.
The posterior horn of the lateral meniscus is attached to the medial condyle of the femur via anterior and posterior meniscofemoral ligaments. These pass in front and behind the posterior cruciate ligament, respectively.
Function
The menisci of the knee joint function to widen and deepen the tibial articular surfaces that receive the femoral condyles, providing stability to the knee joint.
Both the lateral and medial menisci slide backwards with flexion and forwards in extension at the knee joint and act as shock absorbers in the knee joint. The menisci can be injured or torn by twisting the knee or applying direct force to them, as seen in contact sports. The lateral meniscus moves more compared to the medial meniscus, and hence is less prone to injury compared to the medial meniscus. The latter is denied free mobilization because of its additional attachments to the fibrous capsule and the medial collateral ligament.
List of Clinical Correlates
—Meniscal tears
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Lateral Meniscus
2 It results when the lateral meniscus does not differentiate into a semilunar shape and instead forms a thick wafer of fibrocartilaginous tissue.
