青少年特发性脊柱侧凸是一种常见于10~18岁青少年的脊柱三维畸形，其发病率高，进展速度快，给患者带来了极大的身体和心理负担。目前，支具治疗是国际脊柱侧凸研究会唯一认可的保守治疗方式，能够有效缓解侧凸进展并在一定程度上矫正畸形。尽管市面上已经存在众多支具产品可供选择，但支具治疗仍存在种种问题：支具制作依赖支具师的经验和直觉，缺乏个性化设计，支具佩戴缺乏科学指导标准，矫形多针对冠状面但忽视矢状面和轴状面。归根结底是支具矫形过程中矫形力与矫形效果之间的生物力学规律不明。因此，探究矫形力的位置、大小、方向等生物力学因素对矫形效果的影响意义重大，可以为支具设计、佩戴提供理论依据，提高治疗效果。本课题采用有限元法与标本实验相结合的方法，分析了不同矫形力对脊柱变形的作用效果。首先根据患者CT数据建立脊柱三维模型，依据椎体结构对椎间盘、韧带、关节软骨等进行填充，从几何形态和分节段生物力学两方面对模型进行评估。再对模型进行调整，建立顶椎从T7到T11节段的病理模型。从冠状面、矢状面、轴状面三个维度分别选择Cobb角、旋转角、T1椎体质心位移三个指标，衡量单一横向力、纵向力、旋转力的三维矫正效果，进一步拓展二维组合力、三维组合力的矫形效果，探究顶椎位置不同的模型矫形力与矫形效果之间的关系。最后使用猪脊柱标本实验与有限元结果比较验证。研究发现，横向力对脊柱冠状面和矢状面畸形均有较好的矫正效果，但会加重脊柱旋转；纵向力对脊柱侧凸矫正效果不如横向力，但不会加重椎体旋转；旋转力能够有效矫正椎体旋转，但对侧弯无矫正。纵向力矫形效果可以被横向力和旋转力组合替代，各矫形力在矢状面矫形潜能近似，与对应指标之间近似呈线性相关，且顶椎节段变化相关系数也会产生相应的改变。在此基础上，搭建了计算平台，以初始Cobb角、目标矫正Cobb角、初始旋转角、目标矫正旋转角为输入对象，横向力和旋转力为输出对象，进一步探究了支具与躯干间接触力与最终作用到脊柱的矫形力之间的关系，实现个性化治疗。
Adolescent idiopathic scoliosis is a three-dimensional spinal deformity commonly seen in adolescents aged 10 to 18. It has a high incidence and rapid progression, which brings great physical and psychological burdens to patients. At present, brace treatment is the only conservative treatment approved by the International Scoliosis Association, which can effectively alleviate the progression of scoliosis and correct the deformity to a certain extent. Although there are already many braces on the market to choose from, there are still various problems: the production of braces depends on the experience and intuition of the bracer, lack of personalized design, lack of scientific guidance standards for brace wearing, and orthopedics mostly focus on the neglect of the coronal plane Sagittal and axial planes. In the final analysis, the biomechanical law between the orthopedic force and the orthopedic effect during the brace orthopedic process is unclear. Therefore, it is of great significance to explore the influence of biomechanical factors such as the position, magnitude, and direction of the orthopedic force on the orthopedic effect, which can provide a theoretical basis for the design and wearing of the brace and improve the therapeutic effect.In this subject, the combination of finite element method and specimen experiment is used to analyze the effects of different orthopedic forces on spinal deformation. Firstly, a three-dimensional model of the spine is established based on the patient‘s CT data, and the intervertebral disc, ligament, articular cartilage, etc. are filled according to the vertebral body structure, and the model is evaluated from two aspects of geometric shape and segmental biomechanics. Then the model was adjusted, and the pathological models of the T7-T11 segments of the apical vertebrae were established. Select three indicators of Cobb angle, rotation angle, and T1 vertebral centroid displacement from the three dimensions of coronal plane, sagittal plane, and axial plane, respectively, to measure the three-dimensional correction effect of single lateral force, longitudinal force, and rotational force, and further expand the two-dimensional The orthopedic effect of combined force and three-dimensional combined force was used to explore the relationship between the orthopedic force and the orthopedic effect of models with different apical vertebral positions. Finally, the pig spine specimen experiment was compared with the finite element results for verification.The study found that the transverse force has a good correction effect on the coronal and sagittal plane deformities of the spine, but it will aggravate the rotation of the spine; Effective correction of vertebral body rotation, but no correction of scoliosis. The orthopedic effect of longitudinal force can be replaced by the combination of lateral force and rotational force. The orthopedic potential of each orthopedic force in the sagittal plane is similar, and there is approximately a linear correlation with the corresponding index, and the correlation coefficient of the change of the apical vertebral segment will also change accordingly. On this basis, a computing platform was built, with initial Cobb angle, target corrected Cobb angle, initial rotation angle, target corrected rotation angle as input objects, lateral force and rotation force as output objects, and further explored the relationship between the brace and the trunk. The relationship between the contact force and the final orthopedic force applied to the spine enables personalized treatment.
