Early diagnosis of atlanto-axial rotatory fixation.

Atlanto-axial rotatory fixation is one of a spectrum of rotatory abnormalities of the atlanto-axial joint. Rotatory fixation without anterior displacement of the atlas (Type I) has been reported in only a few cases in which there has been a prolonged interval between injury and diagnosis. The majority of these cases eventually required cervical fusion for persistent deformity or instability. Two cases are presented in which this diagnosis was made early with the aid of rotated odontoid radiographs, tomography and computerised axial tomography. Treatment by a short period of halter traction achieved reduction and early return of function. The authors conclude that early recognition and treatment of this rare condition may prevent the subsequent deformity and instability for which cervical fusion has been required.