Segmentation failure of the spine: clinical, surgical and genetic aspects, review of 10 cases

ABSTRACT

In this study we report 10 cases of vertebral segmentation failure with the [bone within bone] appearance with almost complete fusion of the spine suggested ossification of the notochord and perinotochord sheath. Their age ranged from 6-51 year [the mean age was 29 years], there were 5 males and 5 females. Four of our cases were fused in the cervical region, while six were in the thoracolumbar and lumbar regions. The clinical presentation of each case, as well as the radiological findings and the surgical management are discussed in detail. The possible role of the Pax-1 gene and the signalling between the notochord and sclerotome are discussed, concluding that an early defect of the notochord may be responsible for this type of failure of segmentation. A critical review of clinical lessons learned in the operative treatment is also presented