Arcuate popliteal ligament

Looks like

A Y-shaped band on the back and outer side of the knee capsule, from the fibular head arching over the popliteus tendon.

What it does

Reinforces the back-outer corner of the knee.

Keeping it well

Injured in outer-corner knee injuries; missed injuries leave the knee unstable after ACL repair.

Related conditions

• ACL & meniscus injury
• Baker's (popliteal) cyst
• Chronic venous insufficiency
• Gout
• Growing pains
• Haemophilia & bleeding disorders
• Juvenile idiopathic arthritis
• Lyme disease
• Lymphatic filariasis (elephantiasis)
• Lymphoedema
• Marfan syndrome & connective tissue disorders
• Osteoarthritis
• Pseudogout (calcium pyrophosphate disease)
• Psoriatic arthritis
• Reactive arthritis
• Restless legs syndrome
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Septic arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder
• Varicose veins