Chittiboina Prashant, Wylen Esther, Ogden Alan, Mukherjee Debi P, Vannemreddy Prasad, Nanda Anil
Department of Neurosurgery, Louisiana State University Health Sciences Center-Shreveport, Shreveport, LA, USA.
J Neurosurg Spine. 2009 Oct;11(4):379-87. doi: 10.3171/2009.4.SPINE08516.
Surgical management of unstable traumatic spondylolisthesis of the axis includes both posterior and anterior fusion methods. The authors performed a biomechanical study to evaluate the relative stability of anterior fixation at C2-3 and posterior fixation of C-1 through C-3 in hangman's fractures.
Fresh-frozen cadaveric spine specimens (occipital level to T-2) were subjected to stepwise destabilization of the C1-2 complex, replicating a Type II hangman's fracture. Intact specimens, fractured specimens, and fractured specimens with either anterior screw and plate or posterior screw and rod fixation were each tested for stability. Each spine was subjected to separate right and left rotation, bending, flexion, and extension testing.
Anterior fixation restored stiffness in flexion and extension movements to values greater than those for intact specimens. For other movement parameters, the values approximated those for intact specimens. Posterior fixation increased the stiffness to above those values seen for anterior fixation specimens.
In cadaveric spine specimens subjected to a Type II hangman's fracture, both anterior fixation at C2-3 and posterior fixation with C-1 lateral mass screws and C-2 and C-3 pedicle screws resulted in a consistent increase in stiffness, and hence in stability, over intact specimens.
枢椎不稳定创伤性椎体滑脱的手术治疗包括后路和前路融合方法。作者进行了一项生物力学研究，以评估枢椎椎弓根骨折中C2-3前路固定和C1至C3后路固定的相对稳定性。
将新鲜冷冻的尸体脊柱标本（枕骨水平至T-2）进行C1-2复合体的逐步失稳处理，模拟II型枢椎椎弓根骨折。分别对完整标本、骨折标本以及采用前路螺钉钢板或后路螺钉棒固定的骨折标本进行稳定性测试。对每个脊柱进行单独的左右旋转、侧弯、前屈和后伸测试。
前路固定使前屈和后伸运动的刚度恢复到大于完整标本的值。对于其他运动参数，其值接近完整标本。后路固定使刚度增加到高于前路固定标本的值。
在遭受II型枢椎椎弓根骨折的尸体脊柱标本中，C2-3前路固定以及采用C1侧块螺钉和C2、C3椎弓根螺钉的后路固定均导致刚度持续增加，从而相对于完整标本提高了稳定性。
