A Research into the Development of the Device for Correcting and Fixating Infantile and Juvenile Scoliosis

该研究的目的是开发一种延长棒系统纠正婴儿和青少年脊柱侧凸。这套新系统是在千叶脊柱系统（CSS）的基础上，为了满足儿童的成长需要，在仪器的中心增加了一个移动系统。根据移动系统的形状，开发了三种仪器。A型由一个直径为13毫米的外气缸组成，双结构齿轮固定在气缸中，以允许向两端延伸。B型是一个直径12毫米的移动系统类似于a型。C型由一个手动操作的移动系统测量直径10毫米，以允许伸长率。用30度和50度弯曲的Rigolac材料制作脊柱模型进行生物力学研究，其稳定性弱于CSS双棒，但与单棒相当，其中B型效果最好。用Beagle犬进行的动物实验表明，在将系统安装在犬体内3周、6周和12周后，尽管软组织的张力有所增加，但杆仍然可以被拉长。但在12周的犬中，有必要释放软组织以延长棒。结果使我们确信，即使在安装该系统12周后，也可以通过小的皮肤切口手动拉长杆。为了避免在临床使用时内固定失败，我们相信通过在弯曲的凸侧添加压缩棒可以获得更好的稳定性。我们也期待一个电机可以安装到a型和B型，允许齿轮的自动旋转和延伸，而无需进一步的手术入侵。通过这项研究，开发了一种新设计的移动系统，固定在杆的中心，允许伸长率，以纠正和固定婴儿和青少年脊柱侧凸弯曲。

The study is aimed to develop a elongating rod system for correcting infantile and juvenile scoliosis. This new system is based on the Chiba Spinal System (CSS), in order to meet the requirement of the growth of the children, a mobile system is added to the center of the instrument. According to the shape of the mobile system, three kinds of instrumentation are thus developed. Type A consists of a outer cylinder with 13 mm in diameter, and a double structural gear is fixed into the cylinder to allow the elongation toward both ends. Type B is with a 12 mm in diameter mobile system similaly to type A.Type C consists of a manually operated mobile system measured 10 mm in diameter to allow the elongation. Biomechanical study using spinal model made by Rigolac materials of 30 and 50 degree of curvature reveals that it is weaker than the stability of CSS dual rods but is equivalent to that of single rod, the type B shows the best result among all. Animal experiments using Beagle dog shows that the rod can be elongated in 3 weeks, 6 weeks, and 12 weeks after installation of the system into dogs, despite that the tension of the soft tissue is increased. But it is necessary to release soft tissue to elongate the rod in 12 weeks dogs. The result convinces us that even after 12 weeks after installation of this system, the rod can be elongated manually with a small skin incision.To avoid instrumentation failure in clinical usage, we are convinced that better stability can be achieved by adding a compression rod into the convex side of the curvature.We are also looking foward to a motor can be installed into type A and B to allow automatic rotation of the gear and elongation without further surgical invasion.Through this study, a newly designed mobile system fixed into the center of the rod to allow elongation for correcting and fixating infantile and juvenile scoliotic curvature is developed.