Atlantoaxial mobility after screw fixation of the odontoid: a computed tomographic study.

Summary Between 1979 and 1989, anterior screw fixation of the odontoid process was performed in 16 patients with fractures of the odontoid. One patient died suddenly 2 days after the operation. Postmortem examination could not disclose the cause of death. No other complication was noted. We followed 13 patients. At examinations 7 to 82 months after injury, all fractures were consolidated in reduced position. In all patients, a functional computed tomographic (CT) examination of the atlantoaxial rotation was performed. Atlantoaxial rotation measurement ranged from 7 to 38° to the right (average: 25.2°) and 7 to 41° (average: 24.1°) to the left side. Five patients presented a normal range of atlantoaxial rotation, 29 to 41 °; 3 had a rotation of 20 to 28°; 3 a rotation of 10 to 20°; and in 2, rotation was