Gardner-Morse M, Stokes I A
Department of Orthopaedics and Rehabilitation, University of Vermont, Burlington 05405.
J Biomech. 1994 Feb;27(2):177-81. doi: 10.1016/0021-9290(94)90206-2.
The derotation maneuver using Cotrel-Dubousset instrumentation (CDI) is intended to correct the counterdirectional transverse plane rotations of the spine and of the vertebrae in thoracic scoliosis. This was simulated in a finite element model of an idealized thoracic scoliosis with an initial 65 degrees scoliosis angle and 0 degree kyphosis angle. After 90 degrees of rod rotation the apical vertebra derotated 50 degrees towards the sagittal plane but the apical vertebra axial rotation worsened by 8 degrees. The scoliosis angle corrected to 29 degrees and a 54 degrees kyphosis was created. If the initial rod curvature was reduced by 9 degrees, the model predicted only small changes in spinal curvature resulting from the forces required to connect the vertebrae to the hooks. Decreased kyphosis and scoliosis curvatures but increased vertebra axial rotation were produced by the derotation maneuver. The increase in apical vertebra axial rotation was reversed by modifying the representation of the motion segments by repositioning their effective axes 30 mm posteriorly.
使用 Cotrel-Dubousset 器械（CDI）进行的去旋转操作旨在纠正胸椎侧弯中脊柱和椎体在横向平面的反向旋转。这在一个理想化胸椎侧弯的有限元模型中进行了模拟，该模型初始侧弯角度为65度，后凸角度为0度。在棒旋转90度后，顶椎向矢状面旋转了50度，但顶椎的轴向旋转恶化了8度。侧弯角度矫正至29度，并产生了54度的后凸。如果初始棒的曲率减小9度，该模型预测由于将椎体连接到钩所需的力导致的脊柱曲率变化很小。去旋转操作导致后凸和侧弯曲率减小，但椎体轴向旋转增加。通过将运动节段的有效轴向后重新定位30 mm来修改运动节段的表示，可逆转顶椎轴向旋转的增加。
