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CHAPTER 11
Isolated dislocations of the atlas against the axis are not very common, but gross
forward or retro-dislocation and rotation may result in immediate death. Forward
dislocation of one lateral mass may cause a marked rotatory movement of the head to the
opposite side, resulting in a torticollis and neck stiffness. Braakman & Penning (1971)
have recently given instructive examples of atlanto-axial rotation dislocation in children
resulting in torticollis, and posterior atlanto-axial dislocation without fracture of the
odontoid process has been described by Horalson & Boyd (1969), and Wadia (1967)
reported a great incidence of congenital atlanto-axial dislocation in India. Sometimes
fractures of spinous process or dislocation of the atlas against the axis not producing
any cord or root damage may be overlooked if they are associated with a fracture of
the distal parts of the vertebral column which causes the paraplegia, as shown in Fig. 43
demonstrating a fracture of the posterior arch of the atlas in such a case.
(b) FRACTURES OF THE ODONTOID
Fractures and dislocations of the odontoid are also produced by forces acting in vertical
direction or combined with retroflexion caused by a direct blow, falling on the head or
FIG. 44.
