Ishii Takahiro, Mukai Yoshihiro, Hosono Noboru, Sakaura Hironobu, Fujii Ryutaro, Nakajima Yoshikazu, Tamura Shinichi, Sugamoto Kazuomi, Yoshikawa Hideki
Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Suita, Osaka, Japan.
Spine (Phila Pa 1976). 2004 Dec 15;29(24):2826-31. doi: 10.1097/01.brs.0000147806.31675.6b.
Three-dimensional intervertebral motions of the subaxial cervical spine during head rotation were investigated in healthy volunteers using three-dimensional magnetic resonance imaging (MRI).
To document intervertebral coupled motions of the subaxial cervical spine during rotation.
In vivo three-dimensional kinematics of the subaxial cervical spine in rotation have not previously been well described, since they are too complicated to follow using conventional radiography or computed tomography techniques.
Ten healthy volunteers underwent three-dimensional MRI of the cervical spine in 11 positions with 15 degrees increments during head rotation using a 1.0-T imager. Relative motions of the subaxial cervical spine were calculated by automatically superimposing a segmented three-dimensional MRI of the vertebra in the neutral position over images of each position using volume registration. Three-dimensional motions of adjacent vertebrae were represented with 6 df (6 degrees of freedoms) by Euler angles and translations on the coordinate system defined by Panjabi, then visualized in animations using surface bone models.
Mean axial rotation of the subaxial cervical spine in maximum head rotation (69.5 degrees ) was 2.2 degrees at C2-C3, 4.5 degrees at C3-C4, 4.6 degrees at C4-C5, 4.0 degrees at C5-C6, 1.6 degrees at C6-C7, and 1.5 degrees at C7-T1. Coupled lateral bending with axial rotation was observed in the same direction as axial rotation at all levels (C2-C3, 3.6 degrees ; C3-C4, 5.4 degrees; C4-C5, 5.0 degrees ; C5-C6, 5.3 degrees ; C6-C7, 4.9 degrees ; C7-T1, 1.2 degrees ). Coupled extension with axial rotation occurred in the middle cervical region (C2-C3, 1.4 degrees ; C3-C4, 2.3 degrees ; C4-C5, 1.5 degrees ), while in the lower cervical region, flexion was coupled with axial rotation (C5-C6, 0.9 degrees ; C6-C7, 2.4 degrees ; C7-T1, 3.0 degrees ).
We investigated intervertebral motions of the subaxial cervical spine during head rotation using a three-dimensional imaging system, and obtained the first accurate depictions of in vivo coupled motion. These findings will be helpful as the basis for understanding abnormal conditions.
利用三维磁共振成像（MRI）对健康志愿者在头部旋转过程中颈椎下颈椎节段的三维椎间运动进行了研究。
记录颈椎下颈椎节段在旋转过程中的椎间耦合运动。
此前，颈椎下颈椎节段在旋转时的体内三维运动学尚未得到很好的描述，因为使用传统的X线摄影或计算机断层扫描技术很难追踪这些运动。
10名健康志愿者使用1.0-T成像仪，在头部旋转过程中，以15度的增量在11个位置接受颈椎的三维MRI检查。通过使用体积配准，将中立位椎体的分割三维MRI自动叠加到每个位置的图像上，计算颈椎下颈椎节段的相对运动。相邻椎体的三维运动通过欧拉角和在Panjabi定义的坐标系上的平移，用6个自由度（6 df）表示，然后使用表面骨模型在动画中可视化。
在最大头部旋转（69.5度）时，颈椎下颈椎节段的平均轴向旋转在C2-C3为2.2度，C3-C4为4.5度，C4-C5为4.6度，C5-C6为4.0度，C6-C7为1.6度，C7-T1为1.5度。在所有节段（C2-C3为3.6度；C3-C4为5.4度；C4-C5为5.0度；C5-C6为5.3度；C6-C7为4.9度；C7-T1为1.2度）均观察到与轴向旋转方向相同的轴向旋转耦合侧屈。轴向旋转耦合伸展发生在颈椎中部区域（C2-C3为1.4度；C3-C4为2.3度；C4-C5为1.5度），而在颈椎下部区域，屈曲与轴向旋转耦合（C5-C6为0.9度；C6-C7为2.4度；C7-T1为3.0度）。
我们使用三维成像系统研究了头部旋转过程中颈椎下颈椎节段的椎间运动，并首次获得了体内耦合运动的准确描述。这些发现将有助于作为理解异常情况的基础。
