[Congenital absence of a cervical spine pedicle: misdiagnosis in a context of trauma].

Absence of a cervical spine pedicle is an exceptional congenital anomaly with a characteristic radiographic triad: i) absence of pedicle producing a pseudo-enlargement of the homolateral foramen, ii) dysplastic aspect with posterior displacement of the homolateral facets and lamina, and iii) defect or absence of the homolateral transverse process. It is particularly important to recognize this radiographic picture in order to avoid misdiagnosis, e.g. unilateral fracture-displacement of the facet joints in a context of acute trauma, as occurred in our case, or pathological enlargement of the foramen (neurofibroma) without trauma. We describe the radiographic presentation of this congenital anomaly, stressing the importance of a homolateral oblique view and the usefulness of computed tomography for correct diagnosis.