A radiological study of vertebral and rib malformations in children with myelomeningocele.

Postmortem radiographs from 112 infants with thoracolumbosacral or lumbosacral myelomeningoceles were surveyed for associated vertebral and rib malformations. Sixty-four exhibited a variety of anomalies including hemivertebrae, fused vertebral bodies, fused vertebral arches, fused ribs, absence of ribs and absence of vertebral bodies. Anomalies were commonly associated with the cranial end of a dysraphic spina bifida region; in addition hemivertebrae and rib fusion exhibited peak incidences centred around the seventh cervical and fourth thoracic vertebra respectively. Fusion of vertebral arch elements increased in frequency throughout the thoracic region towards T10. The twelfth pair of ribs were absent in 20% of cases. Apparent absence of vertebral bodies from the caudal end of the vertebral column was seen in 24% of the radiographs.