ANOMALIES OF THE VERTEBRAL BODIES

1. Failure of formation of part of the vertebrae.
• Hemivertebrae.
• Butterfly vertebrae – this results when the notocord persists and is not obliterated. A sagittal cleft may result giving the appearance of a butterfly vertebra.
2. Failure of segmentation of the vertebrae.
• Block vertebrae – occurs due to a disturbance in segmentation of the somites into primordial vertebrae. The vertebral body, vertebral arches and spinous processes may be involved.
• Klippel - Feil anomaly.
3. Diastematomyelia.