Spinal retroflexion in craniorhachischisis: its classification and limitations.

Spinal retroflexion has been studied in five stillborn human fetuses having craniorhachischisis. The findings show that retroflexion in this variant of anencephaly can be classified into severe, moderate and mild forms. The three grades can be differentiated from one another by the direction of the face, shape of the mentothoracic junction, extension of hairline on back, radiographic abnormalities of the spine, and the diaphragmatic defects. It is discussed that, though the anencephalies with severe or moderate degree of cervical retroflexion resemble iniencephaly in their features of spinal retroflexion, those having mild retroflexion are contrasted and should not be categorised with iniencephaly. It is suggested that for precision the term "spinal retroflexion" should be used after duly prefixing it by an appropriate word (severe, moderate or mild) indicating the degree of retroflexion observed.