Arcuate popliteal ligament

The arcuate popliteal ligament is an Y-shaped extracapsular ligament of the knee.   It is formed as a thickening of the posterior fibres of the joint capsule of the knee.  It reinforces the knee joint capsule inferolaterally.

Anatomy
From its fibular attachment, the ligament extends superomedially over the tendon of the popliteus muscle, spreading out superficial to the posterior aspect of the tendon.  

Attachments
Its inferior attachment is at the posterior aspect of the head of the fibula.  

It has two superior attachments:


 * The medial part of the ligament extends superficial to the tendon of popliteus muscle  to attach at the posterior part of the intercondylar area of tibia. 
 * The lateral part forms a separate band that extends to the posterior part of the lateral condyle of femur   alongside the tendon of popliteus muscle.