An experimental study on the development of congenital spinal deformity--with special reference to the occurrence and significance of disc anomaly]

This is a histopathological study in mice, using the tail segment of the vertebral column, to investigate the role of intervertebral disc anomalies in the development of congenital spinal deformities. The study was conducted on 222 embryos and 169 postnatal CTT (Crooked-Tailed Toden) mice, a ddY strain with hereditary crooked tails. The earliest detectable anomaly was a serpiginous deformation of the notochord during the notochord stage. Irregular lamination of dense and sparse cell layers of the sclerotome during the membrane stage followed. Then vertebral body and intervertebral disc anomalies clustered around the abnormal notochord, failing to appear separately during the cartilage stage. It was concluded that anomalies of the vertebral body do not appear independently but occur simultaneously with those of the intervertebral disc in the development of congenital spinal deformities. Disc and vertebral body anomalies appear to have equal significance in the pathogenesis of congenital spinal deformities.