Fig. 4From: Atlantoaxial dislocation with congenital “sandwich fusion” in the craniovertebral junction: a retrospective case series of 70 patientsA 51-y/o male patient with severe myelopathy. a lateral radiograph showed sandwich AAD, and ADI = 5.5 mm; b CT indicated C1–2 facet remodeling (sloped from horizontally to vertically); c and d MRI showed Chiari deformity and syringomyelia from C2 to T2; e C2 laminar screw and pedicle screw fixation on 3-year follow-up radiograph (lateral); f 3-year follow-up CT showed the bony fusion between the occiput and the axis; g and h: 3-year follow-up MRI showed the partial relief of Chiari deformity and syringomyeliaBack to article page