arcuate ligamentous complex of the knee

The posterolateral ligamentous complex (also known as the arcuate ligamentous complex) of the knee is an important stabilizer and consists of a number of structures. Depending on the publication/definition more or less of the following structures are included :

• lateral (fibular) collateral ligament
• arcuate ligament
• popliteofibular ligament
• posterior third of the lateral capsule
• fabellofibular ligament (when a fabella is present)
• tendoaponeurotic unit formed by the popliteus muscle (not always included)
• biceps femoris tendon (not always included)
• popliteal meniscal ligament (not always included)
• lateral gastrocnemius muscle (not always included)

Functional classification

Some authors group the structure comprising this ligamentous complex into  in the following functional groups:

• static stabilizers (i.e. posterolateral knee joint capsule)
  • arcuate ligament
  • popliteofibular ligament
  • lateral (fibular) collateral ligament
  • fabellofibular ligament (when the fabella is present)
• dynamic stabilizers
  • tendoaponeurotic unit formed by the popliteus muscle 
  • biceps femoris tendon 
  • lateral gastrocnemius muscle (not always included)
• other structures
  • popliteal meniscal ligament 
  • posterior horn lateral meniscus
  • lateral coronary ligament
  • iliotibial band

Radiographic features

MRI

Components of the posterolateral corner that with some variability can be identified on MRI are:

• biceps femoris tendon
• fibular collateral ligament
• popliteus tendon
• popliteus musculotendinous complex including: 
  • popliteofibular ligament
  • fabellofibular ligament
  • arcuate ligament

Siehe auch:

• Ligamentum popliteum arcuatum
• Ligamentum meniscotibiale
• arcuate ligament
• Außenmeniskus

und weiter:

• arcuate sign
• accessory ligaments of the knee
• Bänder des Kniegelenks