The lateral meniscus, also called the external semilunar fibrocartilage, is a fibrocartilaginous band that spans the lateral side of the interior of the knee

Knee

The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...

 joint. It is one of two menisci

Meniscus (anatomy)

In anatomy, a meniscus is a crescent-shaped fibrocartilaginous structure that, in contrast to articular disks, only partly divides a joint cavity. In humans it is present in the knee, acromioclavicular, sternoclavicular, and temporomandibular joints; in other organisms they may be present in other...

 of the knee, the other being the medial meniscus

Medial meniscus

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. It is nearly circular and covers a larger portion of the articular surface than the medial. It can occasionally be injured or torn by twisting the knee or applying direct force, as seen in contact sports.

Anatomy

The lateral meniscus is grooved laterally for the tendon of the popliteus, which separates it from the fibular collateral ligament

Fibular collateral ligament

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Its anterior end is attached in front of the intercondyloid eminence of the tibia

Tibia

The tibia , shinbone, or shankbone is the larger and stronger of the two bones in the leg below the knee in vertebrates , and connects the knee with the ankle bones....

, lateral to, and behind, the anterior cruciate ligament

Anterior cruciate ligament

The anterior cruciate ligament is a cruciate ligament which is one of the four major ligaments of the human knee. In the quadruped stifle , based on its anatomical position, it is referred to as the cranial cruciate ligament.The ACL originates from deep within the notch of the distal femur...

, 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

Intercondyloid eminence

-Anatomy:Between the articular facets of the proximal tibia, but nearer the posterior than the anterior aspect of the bone, is the intercondyloid eminence , surmounted on either side by a prominent tubercle, on to the sides of which the articular facets are prolonged; in front of and behind the...

.

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

Medial condyle of femur

The medial condyle is one of the two projections on the lower extremity of femur.The medial condyle is larger than the lateral condyle due to more weight bearing caused by the center of gravity being medial to the knee. On the posterior surface of the condyle the linea aspera turns into the...

 of the femur

Femur

The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...

, immediately behind the attachment of the posterior cruciate ligament

Posterior cruciate ligament

The posterior cruciate ligament is one of the four major ligaments of the knee. It connects the posterior intercondylar area of the tibia to the medial condyle of the femur...

.

Occasionally a small fasciculus passes forward to be inserted into the lateral part of the anterior cruciate ligament

Anterior cruciate ligament

The anterior cruciate ligament is a cruciate ligament which is one of the four major ligaments of the human knee. In the quadruped stifle , based on its anatomical position, it is referred to as the cranial cruciate ligament.The ACL originates from deep within the notch of the distal femur...

.

The lateral meniscus gives off from its anterior convex margin a fasciculus which forms the transverse ligament.

Injury and Treatment

The lateral meniscus is less likely to be injured or torn than the medial meniscus. Diagnosis of lateral meniscus tear is done with McMurray's test. If a tear is detected, treatment depends on the type and size of the tear. Small tears can be treated conservatively, with rest, ice, and pain medications until the pain is under control, then exercise may be started with gradually increasing intensity, to improve range of motion and decrease swelling. More severe tears of the lateral meniscus require surgical repair or removal, which can often be done arthroscopically. Swelling and stiffness of the knee can occur when you have a torn lateral meniscus.

External links

• The KNEEguru - educational site packed with knee content with sections on meniscal injuries