butterfly vertebra


but·ter·fly ver·te·bra

a hemivertebra or sagittally cleft vertebra that has a butterfly configuration on frontal radiographs; congenital in origin.
A term for a congenitally anomalous vertebrum accompanied by persistence of the fetal notochord remnant due to incomplete embryologic notochord regression, or chorda dorsalis; sagittal clefts appear, causing a characteristic ‘pinching’ of the superior and inferior aspects of the body and compensatory overgrowth of the vertebral bodies above and below the affected bone