Claybrooks Roderick, Kayanja Mark, Milks Ryan, Benzel Edward
Spine Institute, The Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Spine J. 2007 Nov-Dec;7(6):682-8. doi: 10.1016/j.spinee.2006.08.010. Epub 2007 Apr 16.
Different atlantoaxial fusion techniques are used for instability. Transarticular screws are biomechanically superior to wiring techniques and equivalent to C1 lateral mass to C2 pedicle (C1LM-C2P) fixation. Recently, C1 lateral mass to C2 laminar (C1LM-C2L) fixation has been shown to have flexibility similar to C1LM-C2P fixation in flexion, extension, lateral bending, and axial rotation.
Compare the stiffness of C1LM-C2P with C1LM-C2L screw rod fixation.
In vitro biomechanical study.
Stiffness in flexion/extension, lateral bending, axial rotation, and anterior-posterior (AP) translation.
Eight fresh-frozen human cadaveric cervical spines (C1-C3) were tested intact and, after a type II odontoid fracture, were instrumented and tested with two fixation constructs: C1LM-C2P screws and C1LM-C2L screws. The testing involved flexion, extension, lateral bending, AP translation, and axial rotation. Stiffness was measured and compared with a repeated-measures analysis.
C1LM-C2P was significantly stiffer than the intact in AP translation (p<.001), lateral bending (p=.001), and axial rotation (p=.002) and equivalent in flexion/extension (p=.09). C1LM-C2L was significantly stiffer than the intact in AP translation (p<.01) and axial rotation (p<.004) and equivalent in lateral bending (p<.71) and flexion/extension (p=.22). C1LM-C2P was stiffer than C1LM-C2L in right/left lateral bending (p<.001) and axial rotation (p=.009) and equivalent in AP translation (p=.06) and flexion/extension (p=.74).
C1LM-C2P fixation is equivalent to C1LM-C2L fixation in flexion/extension and AP translation and superior in lateral bending and axial rotation.
不同的寰枢椎融合技术用于治疗不稳定。经关节螺钉在生物力学上优于钢丝技术，且与C1侧块至C2椎弓根（C1LM-C2P）固定相当。最近研究表明，C1侧块至C2椎板（C1LM-C2L）固定在屈伸、侧弯和轴向旋转方面具有与C1LM-C2P固定相似的灵活性。
比较C1LM-C2P与C1LM-C2L螺钉棒固定的刚度。
体外生物力学研究。
屈伸、侧弯、轴向旋转及前后（AP）平移的刚度。
对8具新鲜冷冻的人体颈椎（C1-C3）标本先进行完整状态下的测试，然后造成II型齿突骨折，再用两种固定结构进行器械固定并测试：C1LM-C2P螺钉和C1LM-C2L螺钉。测试包括屈伸、侧弯、AP平移和轴向旋转。测量刚度并通过重复测量分析进行比较。
C1LM-C2P在AP平移（p<0.001）、侧弯（p = 0.001）和轴向旋转（p = 0.002）方面显著比完整状态僵硬，在屈伸方面相当（p = 0.09）。C1LM-C2L在AP平移（p<0.01）和轴向旋转（p<0.004）方面显著比完整状态僵硬，在侧弯（p<0.71）和屈伸（p = 0.22）方面相当。C1LM-C2P在左右侧弯（p<0.001）和轴向旋转（p = 0.009）方面比C1LM-C2L僵硬，在AP平移（p = 0.06）和屈伸（p = 0.74）方面相当。
C1LM-C2P固定在屈伸和AP平移方面与C1LM-C2L固定相当，在侧弯和轴向旋转方面更优。
