Congenital vertebral anomalies and the possible aetiological relationship with spina bifida.

The frequency and distribution of hemivertebrae, fused vertebral bodies, fused vertebral arches and fused ribs were recorded in 376 children and young adults with either spina bifida cystica or occulta, or solitary vertebral body anomalies, or multiple vertebral body anomalies. An attempt was made to find evidence to support the hypotheses that multiple vertebral anomalies and anencephaly-spina bifida are aetiologically related, and that solitary vertebral body anomalies are sporadic and developmentally distinct. Statistical analysis of the distribution of the vertebral and rib defects partly supported these hypotheses.