Tucker S K, Taylor B A
Department of Spinal Deformities, The Royal National Orthopaedic Hospital Trust, Stanmore, Middlesex, UK.
J Bone Joint Surg Br. 1998 Nov;80(6):1073-8. doi: 10.1302/0301-620x.80b6.8911.
In normal, physiological circumstances there is ample room in the spinal canal to accommodate the spinal cord. Our study aimed to identify the degree of compromise of the spinal canal which could be anticipated in various atlantoaxial pathological states. We examined paired atlas and axis vertebrae using high-definition radiography and simultaneous photography in both normal and simulated pathological orientations in order to measure the resultant dimension of the spinal canal and its percentage occlusion. At the extreme of physiological axial rotation (47 degrees) the spinal canal is reduced to 61% of its cross-sectional area in neutral rotation. The spinal cord is thus safe from compromise. Atlantoaxial subluxation of up to 9 mm reduces the area of the spinal canal, in neutral rotation, to 60% with no cord compromise. Any rotation is, however, likely to cause cord compression. The mechanism of fixation in atlantoaxial rotatory subluxation could be explained by bony interlocking of the facet joint, reproducible in dry bones.
在正常生理情况下，椎管有足够的空间容纳脊髓。我们的研究旨在确定在各种寰枢椎病理状态下可预期的椎管狭窄程度。我们使用高清射线照相术和同步摄影对正常和模拟病理方向的成对寰椎和枢椎进行检查，以测量椎管的最终尺寸及其阻塞百分比。在生理轴向旋转极限（47度）时，椎管在中立旋转时的横截面积减小到61%。因此脊髓不会受到压迫。高达9毫米的寰枢椎半脱位会使中立旋转时的椎管面积减小到60%，而脊髓不受压迫。然而，任何旋转都可能导致脊髓受压。寰枢椎旋转性半脱位的固定机制可以通过小关节的骨联锁来解释，这在干燥骨骼中可以重现。
