Anterior Cruciate Ligament (ACL): Difference between revisions
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The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. | The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads. | ||
== Attachments == | == Attachments == | ||
=== Origin === | === Origin === | ||
Arises from the posteromedial corner of medial aspect of lateral femoral condyle in the intercondylar notch. This femoral attachment of ACL is on posterior part of medial surface of lateral condyle well posterior to longitudinal axis of the <br> femoral shaft. The attachment is actually an interdigitation of collagen fibers & rigid bone thru transitional zone of <br> fibrocartilage and mineralized fibrocartilage<ref>Wheeless, C,R. Wheeless' Textbook of Orthopaedics. [http://www.wheelessonline.com/ortho/anatomy_of_acl http://www.wheelessonline.com/ortho/anatomy_of_acl] Accessed 8/1/12.</ref>.<br> | Arises from the posteromedial corner of medial aspect of lateral femoral condyle in the intercondylar notch. This femoral attachment of ACL is on posterior part of medial surface of lateral condyle well posterior to longitudinal axis of the <br> femoral shaft. The attachment is actually an interdigitation of collagen fibers & rigid bone thru transitional zone of <br> fibrocartilage and mineralized fibrocartilage<ref>Wheeless, C,R. Wheeless' Textbook of Orthopaedics. [http://www.wheelessonline.com/ortho/anatomy_of_acl http://www.wheelessonline.com/ortho/anatomy_of_acl] Accessed 8/1/12.</ref>.<br> | ||
=== Insertion === | === Insertion === | ||
Anterior to the intercondyloid eminence of the tibia, being blended with the anterior horn of the medial meniscus. The tibial attachment is in a fossa in front of & lateral to anterior spine, a rather wide area from 11 mm in width to 17 mm in AP direction | Anterior to the intercondyloid eminence of the tibia, being blended with the anterior horn of the medial meniscus. The tibial attachment is in a fossa in front of & lateral to anterior spine, a rather wide area from 11 mm in width to 17 mm in AP direction | ||
== Nerve Supply == | == Nerve Supply == | ||
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The ACL is vascularized by branches of the middle genicular artery. | The ACL is vascularized by branches of the middle genicular artery. | ||
== | == Composition == | ||
The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions<ref>Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. [http://www.ncbi.nlm.nih.gov/pubmed/16235056 Anatomy of the anterior cruciate ligament]. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19.</ref>. There are two components of the ACL, the anteromedial bundle (AMB) and the posterolateral bundle (PLB), named according to where the bundles insert into the tibial plateau. | The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions<ref>Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. [http://www.ncbi.nlm.nih.gov/pubmed/16235056 Anatomy of the anterior cruciate ligament]. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19.</ref>. | ||
== Bundles == | |||
There are two components of the ACL, the smaller anteromedial bundle (AMB) and the larger posterolateral bundle (PLB), named according to where the bundles insert into the tibial plateau. The anteromedial bundle is tight in flexion and the posterolateral bundle is tight in extension. In extensio both bundles are parallel; in flexion the femoral insertion site of the posterolateral bundle moves anteriorly, both bundles are crossed, the anteromedial bundle tightens and the posterolateral bundle loosens. | |||
== Function == | == Function == | ||
Revision as of 13:44, 8 January 2012
Introduction[edit | edit source]
The anterior cruciate ligament (ACL) is a band of dense connective tissue which courses from the femur to the tibia. The ACL is a key structure in the knee joint, as it resists anterior tibial translation and rotational loads.
Attachments[edit | edit source]
Origin[edit | edit source]
Arises from the posteromedial corner of medial aspect of lateral femoral condyle in the intercondylar notch. This femoral attachment of ACL is on posterior part of medial surface of lateral condyle well posterior to longitudinal axis of the
femoral shaft. The attachment is actually an interdigitation of collagen fibers & rigid bone thru transitional zone of
fibrocartilage and mineralized fibrocartilage[1].
Insertion[edit | edit source]
Anterior to the intercondyloid eminence of the tibia, being blended with the anterior horn of the medial meniscus. The tibial attachment is in a fossa in front of & lateral to anterior spine, a rather wide area from 11 mm in width to 17 mm in AP direction
Nerve Supply[edit | edit source]
The ACL is innervated by posterior articular branches of the tibial nerve.
Vascular Supply[edit | edit source]
The ACL is vascularized by branches of the middle genicular artery.
Composition[edit | edit source]
The ACL has a microstructure of collagen bundles of multiple types (mostly type I) and a matrix made of a network of proteins, glycoproteins, elastic systems, and glycosaminoglycans with multiple functional interactions[2].
Bundles[edit | edit source]
There are two components of the ACL, the smaller anteromedial bundle (AMB) and the larger posterolateral bundle (PLB), named according to where the bundles insert into the tibial plateau. The anteromedial bundle is tight in flexion and the posterolateral bundle is tight in extension. In extensio both bundles are parallel; in flexion the femoral insertion site of the posterolateral bundle moves anteriorly, both bundles are crossed, the anteromedial bundle tightens and the posterolateral bundle loosens.
Function[edit | edit source]
Resists anterior translation and medial rotation of the tibia, in relation to the femur.
References[edit | edit source]
- ↑ Wheeless, C,R. Wheeless' Textbook of Orthopaedics. http://www.wheelessonline.com/ortho/anatomy_of_acl Accessed 8/1/12.
- ↑ Duthon VB, Barea C, Abrassart S, Fasel JH, Fritschy D, Ménétrey J. Anatomy of the anterior cruciate ligament. Knee Surg Sports Traumatol Arthrosc. 2006 Mar;14(3):204-13. Epub 2005 Oct 19.
