Roche Clare J, King Susan J, Dangerfield Peter H, Carty Helen M
Department of Medical Imaging, University of Liverpool, Liverpool, UK.
Clin Radiol. 2002 Feb;57(2):103-8. doi: 10.1053/crad.2001.0703.
To measure the range of rotation and determine the instantaneous axis of rotation of the atlanto-axial joint in healthy volunteers using magnetic resonance imaging (MRI) and to highlight the appearances of the rotated atlanto-axial joint on computed tomography (CT) and MRI.
Twenty-eight healthy volunteers were examined using MRI during maximal head rotation. In addition, an anatomical specimen of the atlanto-axial joint, fixed in varying degrees of rotation, was imaged using CT.
At the extremes of physiological rotation in healthy subjects there is striking but incomplete loss of contact between the articular surfaces of the atlas (C1) and the axis (C2). The range of rotation to the right was 20-48.5 degrees (mean 32.4 degrees ) and to the left was 13-52.75 degrees (mean 34.2 degrees ). There was no significant difference between rotation to the right and left (P = 0.455). Total rotation was 45-88.5 degrees (mean 69.25 degrees ). The instantaneous axis of rotation was located within the odontoid peg.
There is a wide range of atlanto-axial rotation in normal subjects. The instantaneous axis of rotation lies within the odontoid peg. The appearances of the rotated atlanto-axial joint are striking and may be misinterpreted as subluxation.
使用磁共振成像（MRI）测量健康志愿者寰枢关节的旋转范围并确定其瞬时旋转轴，同时突出旋转的寰枢关节在计算机断层扫描（CT）和MRI上的表现。
28名健康志愿者在头部最大旋转时接受MRI检查。此外，对处于不同旋转程度固定状态的寰枢关节解剖标本进行CT成像。
在健康受试者生理旋转极限时，寰椎（C1）和枢椎（C2）关节面之间存在明显但不完全的接触丧失。向右旋转范围为20 - 48.5度（平均32.4度），向左旋转范围为13 - 52.75度（平均34.2度）。左右旋转之间无显著差异（P = 0.455）。总旋转范围为45 - 88.5度（平均69.25度）。瞬时旋转轴位于齿突内。
正常受试者寰枢关节有广泛的旋转范围。瞬时旋转轴位于齿突内。旋转的寰枢关节表现明显，可能被误诊为半脱位。
