Vertebral anomalies

The vertebral column is affected by a range of anatomical variants of the body and/or neural arch as well as accessory ossicles. Knowledge of basic vertebral anatomy and ossification is essential for describing and understanding the range of anomalies.

Variant anatomy

Vertebral body

• hemivertebra
• block vertebra
• fused vertebra
• unfused vertebra
• butterfly vertebra

Neural arch

• arcuate foramen
• congenital anomalies of the posterior atlas arch
• transitional vertebrae
  • cervical rib
  • lumbar rib
  • lumbarisation of S1
  • sacralisation of L5

Spinous process

• unfused spinous process
• deviated spinous process
• bifid spinous process (atypical for the level e.g. C7)

Accessory ossicles

• accessory ossicle of the anterior arch of the atlas
• Oppenheimer ossicle
• os odontoideum
• persistent ossiculum terminale
• sesamoid ossicles of the nuchal ligament

Associations

Vertebral anomalies can occur with numerous syndromic as well as non-syndromic conditions including:

• VATER anomaly / VACTERL association
• Aicardi syndrome
• cleidocranial dysostosis
• cloacal exstrophy
• Goldenhar syndrome
• Gorlin syndrome
• Jarcho-Levin syndrome
• Juberg-Hayward syndrome
• Klippel Feil syndrome
• OEIS complex