Atlas-Axis Dislocation Following Cervical Adenitis
ROTARY dislocation of the atlas on the axis in association with infections about the head and neck and without known trauma is a syndrome which is seldom described. The rarity of the lesion is more apparent than real and is related to a general lack of familiarity with this syndrome on the part of the physicians. The condition was described as early as 1908.1 The diagnosis is easily established and treatment is simple.
Anatomically, there is a forward rotary dislocation of the atlas on the axis. The articular facet on one side or the other of the atlas slips forward and downward on its opposing member on the axis and locks into position. The motion is a rotary one on the dens and requires relaxation of the various ligaments supporting the atlanto-axial articulation. There is no apparent fracture in the dens or tearing of the transverse ligament.
Clinically, this syndrome is most often found in children of either sex between the ages of 5 and 12.2 In our experience, it is most frequently seen following painful cervical adenitis. However, it has also been described following acute rheumatic fever, scarlet fever, mastoiditis, tonsillitis, tonsillectomy and nasopharyngitis.3,4,5 The child apparently holds his head to one side to relieve the pain of a cervical adenitis and, after a variable period of time, he is unable to straighten it. When the syndrome develops following such an episode, the presenting problem is one of painful torticollis. Frequently all signs of the initial adenitis have disappeared.