半脊椎所致先天性脊柱侧凸三维矫形有限元模拟分析*☆

背景：对于半脊椎切除后长、短节段和前、后路固定矫形的选择，主要根据医生的临床经验。国内外对于半脊椎所致先天性脊柱侧凸的建模和研究尚未见报道。 目的：运用有限元法模拟半脊椎所致先天性脊柱侧凸三维矫形，分析半脊椎切除后不同固定方式的矫形效果和生物力学特点。 方法：通过有限元软件，利用基于CT图像建立的个体化半脊椎所致先天性脊柱侧凸三维有限元模型，仿真模拟半脊椎切除、前路或后路螺钉固定三维矫形技术，输出选择前路或后路固定矫形，以及不同节段固定的矫形结果。 结果与结论：顺利完成了模拟操作，半脊椎切除后，后路固定矫形效果好于前路固定矫形，特别是对后凸角的矫正，矫正率均大于50%；后路短节段固定矫形与长节段固定矫形在对脊柱侧后凸矫形效果上相差不大，差异值小于5°。针对该患者的个体化有限元模拟试验表明，在半脊椎切除后，后路短节段固定矫形为较好的治疗方案，能减少固定节段，并可获得满意的矫正率。

Finite element simulation of three-dimensional correction in the treatment of congenital scoliosis caused by hemivertebrae

BACKGROUND: For the surgical treatment of congenital scoliosis caused by hemivertebrae, the choice of anterior, posterior approach and long, short segment fixation, is mainly based on clinical experience of doctors. The biomechanical studies are insufficient. There are no reports about finite element modeling and simulating on congenital scoliosis caused by hemivertebrae. OBJECTIVE: To establish an individual three-dimensional finite element model to simulate three-dimensional correction surgery, and to investigate correction effectiveness and biological characteristics with different surgical methods. METHODS: A finite element model of a congenital scoliosis caused by hemivertebrae was constructed using finite element software, and then the individual finite element model was applied to simulate hemivertebra resection with different instrumentation strategies, and pull out the correction effects. RESULTS AND CONCLUSION: Posterior instrumented fusion was better than anterior instrumented fusion after hemivertebrae resection, especially for the kyphosis angle correction, and the ratio was all above 50%; and the differences between posterior short-segment fixation and long-segment after hemivertebrae resection were not obvious within 5°. The surgical simulations showed that posterior short-segment fixation with hemivertebrae resection is the better treatment strategy, which can obtain satisfactory corrective rate with fewer fixed segments for the congenital scoliosis patient caused by hemivertebrae.