Wallis棘突间固定对腰椎活动度和关节突关节内压的影响

目的：通过生物力学测试Wallis棘突间固定对腰椎活动度和关节突关节内压的影响，为Wallis棘突间固定后关节突关节融合提供理论依据。方法：取3具新鲜小牛的腰椎脊柱标本，肉眼和x线排除畸形和结构性破坏，剔除椎旁肌肉及其筋膜组织，保留所有的韧带、椎间盘及关节囊并维持其完整性，共取（3×L1／L2，3×L3／L4，3×L5／L6）9个节段。采用自身前后对照，标本完整为对照组，Wallis棘突间固定后为实验组，分别测试前屈、后伸、左右侧屈、左右旋转6种运动加载下节段腰椎的活动度和关节突关节内压力，并进行统计学分析。结果：相同载荷后伸下，Wallis棘突间固定后节段腰椎的前屈和后伸活动度明显减少（P〈0．01），左右侧屈和旋转活动时节段腰椎的活动度无统计学意义（P〉0．05）。前屈和后伸活动时关节突关节内平均压力明显降低（P〈0．01），左右侧弯和旋转活动时关节突关节平均压力无统计学意义（P〉0．05）。结论：Wallis棘突间固定能减少腰椎前屈和后伸的活动度，加强脊柱的稳定性，降低腰椎前屈后伸活动时的关节突关节内压力。

Effects of Wallis Posterior Dynamic Stabilization System on the Range of Motion of Lumbar Spine and the Stress of Zygapophysial Joints

Objective To investigate the biomechanical effects on the range ot motion ot lumbar spine and me stress of zygapophysial joints after the implantation of Wallis posterior dynamic stabilization system （the Wallis system） so as to provide a theoretical basis for facet joint fusion after the instrumentation with Wallis system. Methods 3 fresh calf lumbar spine specimens were used. Deformity and structural damage was excluded through visual observation and X-ray detection. Paravertebral muscles and fascia were removed. All the ligaments, discs and joint capsule were retained and maintained their integrity. Take a total of （3 x L1/L2, 3 ~ L3/L4, 3 x L5/L6） 9 segments. Before-after controlled study was used.The control group was complete specimens, while the experimental group was implanted with Wallis system. In two groups, investigated the range of motion of lumbar spine and the stress changes in zygapophysial joints under flexion, extension, left and right flexion, left and right rotation,respectivily. Statistical analysis of the data were done. Results Under the same load, flexion and extension range of lumbar segments decreased significantly after implanted with Wallis system （P 〈 0.01）. There were no significant differences between the two groups on left and right flexion and rotation （P 〉 0.05）. The pressure in the zygapophysial joints was significantly reduced when flexion and extension （P 〈 0.01）. There were no significant changes when side bending and rotation （P 〉 0.05）. Conolusion Wallis system can reduce the lumbar flexion and extension,strengthen the stability of the lumbar spine and reduce the stress of zygapophysial joints when flexion and extension.