The arcuate ligament is part of the posterolateral ligamentous complex of the knee. It is a Y-shaped thickening of the posterolateral capsule, which arises from the fibular styloid and divides into two limbs:

  • Medial limb : curves over the popliteus muscle to join with the oblique popliteal ligament
  • Lateral limb : ascends to blend with the capsule near the lateral gastrocnemius muscle

In individuals with a large fabella, the arcuate ligmanet may be absent replaced by a thick fabellofibular ligament.

Source: Arcuate ligament,