DEVELOPMENT OF TREATMENT WITH RESPECT TO IDIOPATHIC SCOLIOSIS

本研究的目的如下：1.证实特发性脊柱侧凸的屈曲假说，即椎体生长引起的屈曲现象2。基于屈曲假设，确定防止屈曲现象的最佳加固部位3。为使对患者个体进行病因分析并提出最佳治疗方案成为可能，结果如下.使用68，582个单元和84，603个节点构建了具有胸廓的脊柱有限元模型。通过与文献试验结果的对比，确定了盘和接头的材料性能。对49例改变生长部位的病例进行第一、第七、第八屈曲模式的研究，结果表明：第四、第六屈曲模式分别是单、双曲线临床形态的力学成因。另一方面，为了通过实验观察这些屈曲现象， ...更多信息 使用数值模型的数据构建。利用这些模型，通过实验模态分析测量了第二固有振动特征值的变化。结果表明，随着椎体的生长，第二阶固有振动特征值逐渐减小，这一结果证实了屈曲假设.用有限元法分析了椎体对第四、六屈曲模态的临界增长的形状梯度密度，即敏感性。基于数值计算结果，验证了确定最佳加固部位以防止各种模态屈曲现象的可能性.为了使脊柱有限元模型变形以适应患者个体，开发了一种数值方法，该方法使用有限元模型到从CT或MRI图像构建的三维体素模型的变形问题的公式化。将该方法应用于特发性脊柱侧凸的CT图像和站立位X线图像的二维有限元模型的拟合，证明了该方法对患者个体的适用性。但对患者个体的病因学分析有待于进一步研究。少

Objectives of the present research were as follows.1. To confirm a buckling hypothesis for idiopathic scoliosis that is buckling phenomena induced by growth of vertebral bodies2. Based on the buckling hypothesis, to identify optimum reinforcement parts to prevent the buckling phenomena3. To make it possible to analyze etiology for individuals of patients and to indicate the optimum treatments for them Results were as follows.1. A spinal finite element model with thoracic cage was constructed using 68,582 elements and 84,603 nodes. Material properties of disks and joints were identified by comparing with the experimental results by literatures. From the results of the first to the seventh or eighth buckling modes for 49 cases changing growth parts, it was shown that the fourth and the sixth buckling modes are mechanical etiology for clinical shapes of single and double curves respectively. On the other hand, to observe these buckling phenomena by experiment, mechanical spine models were … More constructed using data of the numerical model. With these models, the change in the second natural vibration eigenvalue was measured by experimental modal analysis. The obtained result showing a decrease in the second natural vibration eigenvalue with the growth of vertebral bodies is confirms of the buckling hypothesis.2. Shape gradient density, sensitivity in another word, with respect to maximization problem of the critical growth of vertebral bodies to the fourth and sixth buckling modes was analyzed by the finite element method. Based on the numerical results, possibility to identify optimum reinforcement parts to prevent the buckling phenomena of various modes was demonstrated.3. To deform the spinal finite element model to fit individuals of patients, a numerical method was developed using formulation of morphing problem of finite element models to three dimensional voxel model constructed from CT or MRI images. Applying the method to fitting two dimensional finite element models to CT images and the spinal finite element model to standing X-ray image of idiopathic scoliosis, applicability to individuals of patients was demonstrated. However, etiology analysis for individuals of patients was left in the future work. Less