Medial meniscus
4134469
209053811
2008-04-29T18:42:47Z
Arcadian
104523
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{{Infobox Anatomy |
Name = Medial meniscus |
Latin = meniscus medialis |
GraySubject = 93 |
GrayPage = 343 |
Image = Gray349.png |
Caption = Head of right [[tibia]] seen from above, showing [[menisci]] and attachments of ligaments. (Medial meniscus visible at left.) |
Image2 = Gray348.png |
Caption2 = Left [[knee-joint]] from behind, showing interior ligaments. |
System = |
MeshName = |
MeshNumber = |
}}
The '''medial meniscus''' is a [[fibrocartilage]] band that spans the medial [[knee]], and lies on the head of the [[tibia]]. It is also referred to as the '''internal semilunar fibrocartilage''', as it is nearly semicircular in form. It is a common site of injury, especially if the knee is twisted, as commonly occurs in [[contact sports]].
==Attachments==
Its ''anterior end'', thin and pointed, is attached to the [[anterior intercondyloid fossa]] of the [[tibia]], in front of the [[anterior cruciate ligament]];
Its ''posterior end'' is fixed to the [[posterior intercondyloid fossa]] of the tibia, between the attachments of the [[lateral meniscus]] and the [[posterior cruciate ligament]].
==Function==
The medial meniscus separates the [[tibia]] and [[femur]] and serves as a [[shock absorber]], to increase the contact area between the bones, reducing the peak contact force experienced. It also reduces friction between the two bones to allow smooth movement in the knee.
==Injury==
Acute injury to the medial meniscus fairly often accompanies an injury to the ACL ([[anterior cruciate ligament]]) or MCL ([[medial collateral ligament]]). Healing of the medial meniscus is generally slow. Damage to the outer 1/3 of the meniscus will often fully heal, but the inner 2/3 of the medial meniscus has a limited blood supply and thus limited healing ability. Large tears to the meniscus may require surgical repair or removal. If the meniscus has to be removed (menisectomy) because of injury (either because it cannot heal or because the damage is too severe), the patient has an increased risk of developing [[osteoarthritis]] in the knee later in life.<ref>[http://www.arthroscopy.com/sp05005.htm Torn Cartilage (Meniscus)<!-- Bot generated title -->]</ref><ref>[http://www.orthoassociates.com/meniscus.htm The Meniscus<!-- Bot generated title -->]</ref><ref>[http://orthopedics.about.com/cs/meniscusinjuries1/a/meniscus.htm Meniscus Tear - Torn Cartilage<!-- Bot generated title -->]</ref>
More chronic injury occurs with [[osteoarthritis]], made worse by [[obesity]] and high-impact activity. The medial meniscus and the medial compartment are more commonly affected than the lateral compartment.
==See also==
* [[meniscus (anatomy)|meniscus]]
* [[Tear of meniscus]]
* [[cartilage]]
* [[unhappy triad]]
* [[meniscal cartilage replacement therapy]]
==Additional images==
<gallery>
Image:Gray347.png|Right knee-joint, from the front, showing interior ligaments.
Image:Gray350.png|Sagittal section of right knee-joint.
Image:Gray352.png|Capsule of right knee-joint (distended). Posterior aspect.
Image:Normal medial meniscus.jpg|Normal medial meniscus
</gallery>
==External links==
* [http://www.kneeguru.co.uk/KNEEnotes/node/848 The KNEEguru - educational site packed with knee content with sections on meniscal injuries]
* {{SUNYAnatomyFigs|17|07|06}}
* {{eMedicineDictionary|Medial+meniscus}}
* {{NormanAnatomy|lljoints}} ({{NormanAnatomyFig|antkneejointopenflexed}})
==References==
<references/>
{{Gray's}}
{{Joints of lower limbs}}
{{musculoskeletal-stub}}
[[pt:Menisco medial]]