Multiple growth cartilages in the neural arch.

The origin of growth cartilages in the neural arch of human fetal vertebrae was investigated in an attempt to resolve the conflicting opinion on ossification in this region. Serial sections of developing vertebrae were examined, and three growth cartilages for each half of the neural arch were found. They have their origin from a single center of ossification. Endochondral bone formation similar to ossification in the diaphysis of a long bone occurs in the neural arch. This information may help in the understanding of how vertebral malformations such as scoliosis and spondylolysis occur during postnatal life.