Occipital condyles

Occipital condyles are two rounded knobs on the occipital bone in the skull that form a joint with the first cervical vertebra, allowing the head to move relative to the neck. They are located on the underside of the skull, next to the foramen magnum.

Etymology

The term "occipital" comes from the Latin "occiput" which means "back of the skull". "Condyle" is derived from the Greek "kondylos", meaning "knuckle".

Structure

The occipital condyles are convex, oval-shaped protrusions on either side of the foramen magnum. They are composed of compact bone and are covered by a thin layer of hyaline cartilage to facilitate smooth movement. Each condyle has an anterior and a posterior part. The anterior part is larger and presents a concave surface which articulates with the superior facet of the atlas. The posterior part is convex and connects with the anterior atlanto-occipital membrane.

Function

The occipital condyles, together with the atlas, form the atlanto-occipital joint, which allows nodding movement of the head (flexion and extension). This joint also permits some lateral movement and a small degree of rotation.

Clinical significance

Damage to the occipital condyles can result in occipital condyle syndrome, a rare condition characterized by severe, unilateral, occipital headache and ipsilateral hypoglossal nerve palsy. This condition is usually caused by trauma, infection, or malignancy.

Related terms

• Occipital bone
• Atlas
• Atlanto-occipital joint
• Foramen magnum
• Occipital condyle syndrome

See also

• List of bones of the human skeleton

• 
  Animation of occipital condyle
• 
  Diagram of occipital condyle