Department of Orthopaedic Surgery, University of Toledo Medical Center, Toledo, OH 43614, USA.
Injury. 2009 Nov;40(11):1157-60. doi: 10.1016/j.injury.2009.01.112. Epub 2009 May 31.
Many investigators have conducted studies to determine the biomechanics, causes, complications and treatment of unilateral facet joint dislocation in the cervical spine. However, there is no quantitative data available on morphological changes in the intervertebral foramen of the cervical spine following unilateral facet joint dislocation. These data are important to understand the cause of neurological compromise following unilateral facet joint dislocation.
Eight embalmed human cadaver cervical spine specimens ranging from level C1-T1 were used. The nerve roots of these specimens at C5-C6 level were marked by wrapping a 0.12mm diameter wire around them. Unilateral facet dislocation at C5-C6 level was simulated by serially sectioning the corresponding ligamentous structures. A CT scan of the specimens was obtained before and after the dislocation was simulated. A sagittal plane through the centre of the pedicle and facet joint was constructed and used for measurement. The height and area of the intervertebral foramen, the facet joint space, nerve root diameter and area, and vertebral alignment both before and after dislocation were evaluated.
The intervertebral foramen area changed from 50.72+/-0.88mm(2) to 67.82+/-4.77mm(2) on the non-dislocated side and from 41.39+/-1.11mm(2) to 113.77+/-5.65mm(2) on the dislocated side. The foraminal heights changed from 9.02+/-0.30mm to 10.52+/-0.50mm on the non-dislocated side and 10.43+/-0.50mm to 17.04+/-0.96mm on the dislocated side. The facet space area in the sagittal plane changed from 6.80+/-0.80mm(2) to 40.02+/-1.40mm(2) on the non-dislocated side. The C-5 anterior displacement showed a great change from 0mm to 5.40+/-0.24mm on the non-dislocated side and from 0mm to 3.42+/-0.20mm on the dislocated side. Neither of the nerve roots on either side showed a significant change in size.
The lack of change in nerve root area indicates that the associated nerve injury with unilateral facet joint dislocation is probably due to distraction rather than due to direct nerve root compression.
许多研究人员已经进行了研究，以确定颈椎单侧关节突关节脱位的生物力学、原因、并发症和治疗方法。然而，目前还没有关于颈椎椎间孔形态变化的定量数据。这些数据对于理解单侧关节突关节脱位后神经功能障碍的原因很重要。
使用 8 个从 C1 到 T1 的颈椎尸体标本。通过用 0.12 毫米直径的金属丝缠绕这些标本的 C5-C6 神经根来标记。通过连续切断相应的韧带结构来模拟 C5-C6 水平的单侧关节突脱位。在模拟脱位之前和之后对标本进行 CT 扫描。构建了穿过椎弓根和关节突中心的矢状面，并用于测量。评估了脱位前后椎间孔的高度和面积、关节突关节间隙、神经根直径和面积以及椎体排列。
未脱位侧椎间孔面积从 50.72+/-0.88mm（2）变为 67.82+/-4.77mm（2），脱位侧从 41.39+/-1.11mm（2）变为 113.77+/-5.65mm（2）。未脱位侧的椎间孔高度从 9.02+/-0.30mm 变为 10.52+/-0.50mm，脱位侧从 10.43+/-0.50mm 变为 17.04+/-0.96mm。矢状面上关节突间隙面积从 6.80+/-0.80mm（2）变为未脱位侧的 40.02+/-1.40mm（2）。C5 前移位从 0mm 变为未脱位侧的 5.40+/-0.24mm，从 0mm 变为脱位侧的 3.42+/-0.20mm。两侧神经根的大小均无明显变化。
神经根面积无变化表明单侧关节突关节脱位伴发的相关神经损伤可能是由于牵拉而不是直接神经根受压所致。
