齿轮撑开式脊柱复位固定板装置的研制

背景: 目前临床应用的脊柱后路复位固定的钉棒系统存在一定程度的生物力学的缺陷，钉板系统更适合在患者中广泛使用。目的：依据中国人脊柱的椎弓根间距、弧度、椎体及椎间隙高度的影像学测量结果，研制一种新型的脊柱后路复位内固定板装置。方法：测量129例门诊查体的正常者的胸腰椎数据。依据影像学测量的结果，并在复习文献的基础上，对新型脊柱复位内固定器进行图纸设计及形状设计。取18具新鲜小牛腰椎标本随机分为实验组给予行齿轮撑开式脊柱复位内固定板装置固定，CD及Steffee组分别用CD及Steffee钢板固定，测量标本在受到轴向压缩、前屈、后伸及侧屈载荷状态下的位移、应变、刚度和破坏性能等测试，结果进行统计学处理。结果与结论：齿轮撑开式脊柱复位内固定装置(GDP)能较好地满足人体强、刚度的要求。GDP组测得椎体固定的强度和刚度均比对照组CD和Steffee钢板系统优越(P < 0.05)，腰椎的扭转力学性能比CD，Steffee钢板内固定分别高出13%和14%，腰椎的极限力学性能测试结果显示GDP能承载载荷，比CD,Steffee钢板更大(P < 0.05)。说明齿轮撑开式脊柱复位固定板装置的设计符合中国人脊柱的解剖规格，生物力学稳定性良好，可以显著促进椎骨骨折的愈合，防止脊椎后凸的复发和高度的丧失。

Preparation of a gear distraction plate device for spinal reduction and fixation

BACKGROUND: The most commonly used rod-screw posterior spinal fixation system has some biomechanical drawbacks. The screw-plate system is more preferred for patients. OBJECTIVE: To prepare a new posterior spinal fixation system based on imaging results of distance between two pedicles, radian of spine flexion, extension and the height of intervertebral space of Chinese population. METHODS: The thoracolumbar data of 129 normal people were measured. According to the imaging measurements and relative documents, a device of gear-distraction plate (GDP) for spine reduction and fixation was designed. Eighteen fresh calf lumbar specimens were randomly divided into 3 groups, the test group was fixed by GDP and the other groups were fixed by CD and Steffee plate, respectively. The results of the displacement, strain, strength, stiffness and ultimate strength were measured under the states of vertical compression, flexion, extension and lateral bending respectively, and the results were statistically analyzed. RESULTS AND CONCLUSION: GDP could meet the need of strength and stiffness of human bodies. It showed superior to the CD and Steffee plate groups in strength and stiffness (P < 0.05), with 13% or 14% torsion intensity greater than that of the CD or Steffee plate groups. The ultimate mechanical performance test showed that, the load bearing of the GDP group was greater than that of the CD and Steffee plate groups (P < 0.05). The findings demonstrated that GDP for Chinese human presented with good biomechanical stability, which can promote vertebrae fracture union and prevent kyphosis relapses or vertebral height loses.