Arcuate Ligament

Description

Illustration of the posterior knee including the arcuate ligament

Name

• Arcuate Popliteal Ligament
• Ligamentum Popliteum Arcuatum
• Arcuate Ligament

General

• Part of the posterolateral ligamentous complex of the knee
• Broad band that arises from the posterior aspect of the head of the fibula
• Fibers pass superomedial to the tendon of the popliteus muscle
• Blend with the posterior fibers of the joint capsule of the knee
• Variably present, found in ~65% of knees (need citation)

Anatomic Description

• Y shaped thickening of the posterolateral capsule
• Arises from the fibular styloid
• Two limbs
  • Medial: curves over the popliteus muscle to join with the oblique popliteal ligament
  • Lateral: ascends to blend with the capsule near the lateral gastrocnemius muscle

Variant Anatomy

• In patients with a large fabella
• May be absent, replaced by a thick thick fabellofibular ligament

Function

• Resists excessive external tibial rotation
• Reinforces the knee capsule inferolaterally

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Clinical Significance

• Posterolateral Corner Injury
• Arcuate Ligament Sign

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See Also

• Knee Anatomy Main
• Physical Exam Knee
• Knee Pain Main

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