一例Lenke1BN型青少年特发性脊柱侧凸矫形术后的有限元生物力学分析

目的 用有限元法模拟不同下融合椎（Lower Instrumented Vertebrae，LIV）选择下的青少年特发性脊柱侧凸(adolescent idiopathic scoliosis，AIS)矫形手术，分析术后远端附加现象（Adding-on phenomenon）发生的生物力学基础，为术后预防Adding-on现象提供参考依据和理论支持。 方法 选取在我科手术治疗的1例Lenke1BN型AIS患者，构建全脊柱三维仿真有限元模型，计算机模拟不同LIV选择下的矫形手术，分析不同LIV选择下术后次弯代偿表现及未融合部分各椎间盘最大应力。 结果 未融合部分椎间盘最大应力从远端到近端逐渐增大，当LIV选择在下端椎L1时，L1/2椎间盘最大应力超过L2/3椎间盘最大应力80%以上，当LIV选取在端椎以下椎体L2、L3时，未融合节段椎间盘近端与远端每节的最大应力差别在20%左右。 结论 对于Lenke1BN型AIS患者，LIV选择在端椎下方椎体可减少Adding-on现象发生的风险。

Finite element biomechanical analysis of a Lenke1BN adolescent idiopathic scoliosis case after corrective surgery

Objective Simulate the corrective surgery of adolescent idiopathic scoliosis (AIS) under different Lower Instrumented Vertebrae (LIV) selection by finite element method and analyze the biomechanical basis of Adding-on phenomenon to provide reference and theoretical support for the prevention of Adding-on phenomenon after operation. Methods A Lenke1BN AIS patient treated in our department was selected. A three-dimensional finite element model of the patients spine was constructed. Then, the AIS orthomorphia under different LIV options were simulated by computer to study the sub-curve compensation and the stress of the different unfused intervertebral discs. Results The maximum stress of the unfused intervertebral discs gradually increased from distal to proximal. When the LIV was located at L1,which is the lower end vertebra,the maximum stress of the L1/2 disc was more than 80% higher than that of the L2/3 disc. When the LIV was located at L2 and L3, the maximum stress difference between unfused intervertebral discs was about 20%. Methods For Lenke1BN AIS patients, LIV below the lower end vertebra can reduce the risk of Adding-on phenomenon.