Currier Bradford L, Papagelopoulos Panayiotis J, Neale Patricia G, Andreshak John L, Hokari Yukitaka, Berglund Lawrence J, Larson Dirk R, Fisher Dean R, An Kai-Nan
Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN 55905, USA.
Clin Orthop Relat Res. 2003 Jun(411):103-15. doi: 10.1097/01.blo.0000068760.86536.54.
Twelve fresh-frozen cadaveric occipitocervical specimens were randomized based on dual energy xray absorptiometry analysis of bone mineral density. The specimens were subjected to physiologic loads in a device that applied pure unconstrained flexion and extension, lateral bending, and axial rotational moments. The spines were tested intact and after major injury simulating transoral decompression of the dens. Biomechanical testing using pure moments with physiologic loads (< 1.5 N-m) was used to compare stability of posterior occipitocervical plates and screws, loop and cable construct, and new cervical rod and screw system. The injury created significantly less stiffness and greater range of motion and neutral zone at C1-C2 in flexion and extension and lateral bending and greater range of motion and neutral zone in axial rotation than the intact state. In lateral bending, the new rod construct had significantly lower mean values for range of motion than the loop and the plate construct. In axial rotation, the rod construct had a significantly higher mean value for stiffness than the other two devices and a significantly lower mean value for range of motion than the loop. The new rod-based instrumentation system for occipitocervical fixation is biomechanically equivalent or superior to a plate and screw construct and a rod and cable system.
根据骨密度的双能X线吸收测定分析，将12个新鲜冷冻的尸体枕颈标本进行随机分组。这些标本在一个施加单纯无约束屈伸、侧弯和轴向旋转力矩的装置中承受生理负荷。对脊柱进行完整状态下的测试以及模拟经口齿突减压的重大损伤后的测试。使用生理负荷（<1.5 N-m）下的纯力矩进行生物力学测试，以比较枕颈后路钢板和螺钉、袢与缆线结构以及新型颈椎棒和螺钉系统的稳定性。与完整状态相比，损伤在C1-C2节段的屈伸和侧弯中产生的刚度明显降低，屈伸和侧弯以及轴向旋转中的活动范围和中立区明显增大。在侧弯中，新型棒结构的活动范围平均值明显低于袢和钢板结构。在轴向旋转中，棒结构的刚度平均值明显高于其他两种装置，活动范围平均值明显低于袢。用于枕颈固定的新型基于棒的器械系统在生物力学上等同于或优于钢板和螺钉结构以及棒和缆线系统。
