Atlanto-axial joint

Looks like

Three joints between the atlas (C1) and the axis (C2): the ring of the atlas turning around the upright peg (dens) of the axis, held by the transverse ligament, plus two flat side joints.

What it does

Gives about half of all the head's turning side to side.

Keeping it well

A torn transverse ligament or a broken dens can let the peg press on the cord; rheumatoid arthritis loosens it too. Neck pain after a fall in an older person needs imaging.

Related conditions

• Gout
• Haemophilia & bleeding disorders
• Lyme disease
• Marfan syndrome & connective tissue disorders
• Neck pain and cervical spondylosis
• Osteoarthritis
• Psoriatic arthritis
• Rheumatic fever & rheumatic heart disease
• Rheumatoid arthritis
• Systemic lupus erythematosus
• Temporomandibular joint disorder
• Whiplash
• Wry neck (torticollis)