Canal geometry changes associated with axial compressive cervical spine fracture
Canal geometry changes associated with axial compressive cervical spine fracture
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DOI：
10.1097/00007632-200001010-00010
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发表时间：
2000-01-01
期刊：
影响因子：
3
通讯作者：
Ching, RP
中科院分区：
文献类型：
--
作者：
Carter, JW;Mirza, SK;Ching, RP
研究设计.一项实验室研究，使用离体的人类尸体颈椎韧带，研究轴向压缩性脊柱内固定期间（瞬时）和之后（稳态）椎管闭塞情况。确定在轴向压缩负荷下暂时性和损伤后椎管闭塞之间是否存在差异，并检查负荷率对椎管闭塞的影响。先前的研究表明，神经功能缺损与X线片和计算机断层扫描测量的椎管闭塞之间没有相关性。作者假设，创伤后影像学评估不能评估创伤性骨折事件期间发生的短暂闭塞，这可能会显著影响神经功能结局。十二人颈椎与一个专门设计的椎管闭塞传感器，动态监测椎管闭塞在轴向压缩冲击。6个样本接受快速加载速率（达到峰值载荷的时间，类似于20 msec），其他6个样本接受慢速加载速率（达到峰值载荷的时间，类似于250 msec）。撞击后，进行两种不同的损伤后椎管闭塞测量。每六个样本进行快速加载速率发生爆裂骨折，而缓慢加载速率产生六个楔形压缩骨折。对于快速组，伤后闭塞测量值明显小于短暂闭塞。相反，在慢速组中，暂时性闭塞与损伤后闭塞没有显著差异。加载速率组之间的所有比较均显示出显著差异，在每个类别中，快速骨折均产生更大量的髓腔闭塞。研究结果表明，即使在轴向压缩性创伤后可以立即测量椎管闭塞，该测量也会低估暂时性椎管闭塞的最大量。因此，损伤后测量椎管闭塞可能表明神经功能缺损的程度比可以测量暂时闭塞时预期的程度要小。
Study Design. A laboratory study using isolated ligamentous human cadaveric cervical spines to investigate canal occlusion during (transient) and after (steady-state) axial compressive fracture.Objectives. To determine whether differences exist between transient and postinjury canal occlusion under axial compressive loading, and to examine the effect of loading rate on canal occlusion.Summary of Background Data. Prior studies have shown no correlation between neurologic deficit and canal occlusion measurements made on radiographs and computed tomography scans. The authors hypothesized that postinjury radiographic assessment does not provide an appreciation for the transient occlusion that occurs during the traumatic fracture event, which may significantly affect the neurologic outcome.Methods. Twelve human cervical spines were instrumented with a specially designed canal occlusion transducer, which dynamically monitored canal occlusion during axial compressive impact. Six specimens were Subjected to a fast-loading rate (time to peak load, similar to 20 msec) and the other six were subjected to a slow-loading rate (time to peak load, similar to 250 msec). After impact, two different postinjury canal occlusion measurements were performed.Results. Each of the six specimens subjected to the fast-loading rate incurred burst fractures, whereas the Slow-loading rate produced six wedge-compression fractures. For the fast-rate group, the postinjury occlusion-measurements were significantly smaller than the transient occlusion. In contrast, transient occlusion was not found to be significantly different from postinjury occlusion in the slow-rate group. All of the comparisons between loading rate groups showed significant differences, with the fast-rate fractures producing larger amounts of canal occlusion in every category.Conclusions. The findings indicate that even if canal occlusion could be measured immediately after axial compressive trauma; the measurement would underestimate the maximal amount of transient canal occlusion. Therefore, postinjury measurement of canal occlusion may indicate a smaller degree of neurologic deficit than what might be expected if the transient occlusion could be measured.