Annular ligament of radius

Looks like

A strong ring of fibres wrapped around the head of the radius, attached at both ends to the ulna.

What it does

Holds the radial head against the ulna while letting it spin, so we can turn the palm up and down.

Keeping it well

In toddlers the radial head slips out after a pull on the arm (pulled elbow); a doctor can pop it back quickly.

Related conditions

• Cubital tunnel syndrome
• Gout
• Haemophilia & bleeding disorders
• Lyme disease
• Marfan syndrome & connective tissue disorders
• Osteoarthritis
• Psoriatic arthritis
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder