可调式椎体后凸成形装置的研制及其在胸腰椎骨折中应用的可行性

Application of self-designed adjustable kyphoplasty device in thoracolumbar fractures

中文关键词:  椎体后凸成形装置  胸腰椎骨折  后凸成形术  生物力学

英文关键词:Kyphoplasty device  Thoracolumbar fractures  Kyphoplasty  Biomechanics

中文摘要:

  【摘要】 目的：自行研制一种新型可调式椎体后凸成形装置，探讨其在胸腰椎椎体骨折中应用的可行性。方法：采用钛合金材料制成具有超弹性特性的灯笼状弹性金属球，通过旋进器与套筒使金属球撑开及回收，采用自行设计的测试装置于INSTRON 5544生物力学测试机上测试单片金属片的最大应力载荷和应力变化。取正常成年新鲜尸体胸腰椎脊柱（T12～L2）标本5具，用自凝牙托粉包埋标本的上下两端并暴露L1椎体及上下椎间盘，包埋时使标本前屈10°，将试件置于INSTRON 8874生物力学试验机底座上，采用滚珠液压加载，准静态加载方式，将标本制作成L1椎体创伤性骨折模型，然后经两侧椎弓根扩孔，透视下达椎体内骨折终板下，将可调式后凸成形装置置入，旋转尾端可调式装置撑开灯笼状金属球至最大直径，X线正侧位片观察金属球位置、撑开状态及椎体复位状态，反复操作直到撑开和复位状态达正常L1椎体高度后回旋，推进外套筒拔出后凸成形装置。采用自制的材料推注器将丙烯酸树脂骨水泥Ⅲ经扩大的双侧椎弓根通道填充行椎体重建术。结果：（1）由钛合金钢片组成的灯笼球状金属球初始直径为6.0mm，通过尾端可调式旋进装置调节可使金属球膨胀，最大直径可达12mm；其单片金属片最大应力载荷为56.96±3.21N，应力为9.48±0.53MPa。（2）经直径6.5mm扩孔椎扩孔后，直径为6mm的后凸成形装置可以通过椎弓根至椎体内部，经尾端可调式旋进器调节可使灯笼状球形结构膨胀，撑开复位后回旋能使金属球复位，推进外套筒可拔出装置，完成后凸成形术。5具标本实验操作均成功，椎体高度恢复平均达98.95%。结论：可调式后凸成形装置利用钛合金的弹性及柔韧性，可完成撑开和回收，在治疗胸腰椎椎体骨折中安全可行。

英文摘要:

  【Abstract】 Objectives: To develop a new type of titanium alloy adjustable kyphoplasty device, and to explore its use in the treatment of thoracolumbar vertebral compression fractures. Methods: The lantern-shaped elastic metal ball was made by using the super elastic titanium. After some procedures, the metal ball could endure some distraction and retraction. Applications INSTRON 5544 were used to test the maximum load and stress change by self-designed equipment. 5 normal fresh adult thoracolumbar spine specimens(T12-L2) were used, a self-curing denture powder was embedded in the specimens, and L1 vertebral body and its upper and lower discs were exposed. The specimens were placed in biomechanical testing machine INSTRON 8874 base at flexion 10°, a ball hydraulic loading in quasi-static loading was performed. Then the specimens were transferred into L1 vertebral traumatic fracture models. The adjustable kyphoplasty device was placed in the vertebral bodys, the terminal adjustable device was rotated for distraction and achieve reduction. After that, type Ⅲ acrylic bone cement was infilled in the defect from bilateral pedicle. Results: (1)The initial diameter of lantern-shaped metal ball was 6.0mm, and after rotating the adjustable device, the maximum diameter reached 12mm, the maximum stress load of a single piece was 56.96±3.21N, the stress was 9.48±0.53MPa. (2)After reaming with a diameter of 6.5mm reamer, the kyphoplasty with 6mm diameter could be placed in vertebral body through the pedicle and finish expansion with average height restoration of 98.95%. Conclusions: Adjustable kyphoplasty device is of elasticity and flexibility, which can be used for the treatment of thoracolumbar vertebral fractures.