Cusick Joseph F, Pintar Frank A, Cheng Joseph S, Lifshutz Jason I, Yoganandan Narayan
Department of Neurosurgery, Medical College of Wisconsin and Veterans Affairs Medical Center, Milwaukee, WI, United States.
Department of Neurosurgery, Medical College of Wisconsin and Veterans Affairs Medical Center, Milwaukee, WI, United States; Joint Department of Biomedical Engineering, Medical College of Wisconsin and Marquette University, Milwaukee, WI, United States.
Clin Biomech (Bristol). 2018 Jun;55:18-22. doi: 10.1016/j.clinbiomech.2018.04.001. Epub 2018 Apr 4.
Biomechanical/anatomic limitations may limit the successful implantation, maintenance, and risk acceptance of posterior cervical plate/rod fixation for one stage decompression-fusion. A method of posterior fixation (crisscross) that resolves biomechanical deficiencies of previous facet wiring techniques and not reliant upon screw implantation has been devised. The biomechanical performance of the new method of facet fixation was compared to the traditional lateral mass plate/screw fixation method.
Thirteen human cadaver spine segments (C2-T1) were tested under flexion-compression loading and four were evaluated additionally under pure-moment load. Preparations were evaluated in a sequence of surgical alterations with intact, laminectomy, lateral mass plate/screw fixation, and crisscross facet fixation using forces, displacements and kinematics.
Combined loading demonstrated significantly lower bending stiffness (p < 0.05) between laminectomy compared to crisscross and lateral mass plate/screw preparations. Crisscross fixation showed a comparative tendency for increased stiffness. The increased overall motion induced by laminectomy was resolved by both fixation techniques, with crisscross fixation demonstrating a comparatively more uniform change in segmental motions.
The crisscross technique of facet fixation offers immediate mechanical stability with resolution of increased flexural rotations induced by multi-level laminectomy. Many of the anatomic limitations and potentially deleterious variables that may be associated with multi-level screw fixation are not associated with facet wire passage, and the subsequent fixation using a pattern of wire connection crossing each facet joint exhibits a comparatively more uniform load distribution. Crisscross wire fixation is a valuable addition to the surgical armamentarium for extensive posterior cervical single-stage decompression-fixation.
生物力学/解剖学限制可能会限制一期减压融合术后颈椎后路钢板/棒固定的成功植入、维持及风险接受度。已设计出一种后路固定方法（交叉法），该方法可解决以往小关节钢丝技术的生物力学缺陷，且不依赖螺钉植入。将这种新的小关节固定方法的生物力学性能与传统的侧块钢板/螺钉固定方法进行了比较。
对13个尸体颈椎节段（C2-T1）进行屈伸加载测试，另外4个节段在纯弯矩载荷下进行评估。通过完整、椎板切除、侧块钢板/螺钉固定和交叉小关节固定等一系列手术改变，利用力、位移和运动学对标本进行评估。
联合加载显示，与交叉法和侧块钢板/螺钉固定的标本相比，椎板切除后的弯曲刚度显著降低（p<0.05）。交叉固定显示出刚度增加的比较趋势。两种固定技术均解决了椎板切除引起的整体运动增加问题，交叉固定在节段运动变化上相对更均匀。
小关节固定的交叉技术提供了即时的机械稳定性，解决了多节段椎板切除引起的弯曲旋转增加问题。许多可能与多节段螺钉固定相关的解剖学限制和潜在有害变量与小关节钢丝穿过无关，随后使用穿过每个小关节的钢丝连接模式进行固定，其载荷分布相对更均匀。交叉钢丝固定是广泛的颈椎后路单阶段减压固定手术器械库中的一项有价值的补充。
