De Lorenzo R A, Olson J E, Boska M, Johnston R, Hamilton G C, Augustine J, Barton R
Department of Emergency Medicine, Wright State University School of Medicine, Dayton, Ohio, USA.
Ann Emerg Med. 1996 Sep;28(3):301-8. doi: 10.1016/s0196-0644(96)70029-x.
We hypothesized that optimal positioning of the head and neck to protect the spinal cord during cervical spine immobilization can be determined with reference to external landmarks. In this study we sought to determine the optimal position for cervical spine immobilization using magnetic resonance imaging (MRI) and to define this optimal position in a clinically reproducible fashion.
Our subjects were 19 healthy adult volunteers (11 women, 8 men). In each, we positioned the head to produce various degrees of neck flexion and extension. This positioning was followed by quantitative MRI of the cervical spine.
The mean ratio of spinal canal and spinal cord cross-sectional areas was smallest at C6 but exceeded 2.0 at all levels from C2 to T1 (P < .05). At the C5 and C6 levels, the maximal area ratio was most consistently obtained with slight flexion (cervical-thoracic angle of 14 degrees) (P < .05). For a patient lying flat on a backboard, this corresponds to raising the occiput 2 cm. More extreme flexion or extension produced variable results.
In healthy adults, a slight degree of flexion equivalent to 2 cm of occiput elevation produces a favorable increase in spinal canal/spinal cord ration at levels C5 and C6, a region of frequent unstable spine injuries.
我们假设在颈椎固定期间，可参照外部标志确定保护脊髓的头颈部最佳位置。在本研究中，我们试图利用磁共振成像（MRI）确定颈椎固定的最佳位置，并以临床可重复的方式界定该最佳位置。
我们的研究对象为19名健康成年志愿者（11名女性，8名男性）。对每名志愿者，我们将头部摆放至产生不同程度的颈部屈伸状态。之后对颈椎进行定量MRI检查。
椎管与脊髓横截面积的平均比值在C6处最小，但在C2至T1的所有节段均超过2.0（P < 0.05）。在C5和C6节段，轻微屈曲（颈胸角为14度）时最一致地获得最大面积比值（P < 0.05）。对于平躺在背板上的患者，这相当于将枕骨抬高2厘米。更极端的屈曲或伸展产生的结果各异。
在健康成年人中，相当于枕骨抬高2厘米的轻微屈曲会使C5和C6节段（脊柱损伤常发的不稳定区域）的椎管/脊髓比值产生有利增加。
