颈胸段脊柱全脊椎切除术后不同固定方式的有限元分析  

Finite element analysis on different spine fixation methods after total spondylectomy of cervicothoracic spine

作　　者：方新果[1] 赵改平[1] 王晨曦[1] 柏磊磊 陈二云[2] 赵庆华[3] 

机构地区：[1]上海理工大学医疗器械与食品学院,上海200080 [2]上海理工大学能源与动力工程学院,上海200093 [3]上海市第一人民医院骨科,上海200080

出　　处：《医用生物力学》2015年第3期220-225,共6页Journal of Medical Biomechanics

基　　金：国家自然科学基金项目(51106099);上海市自然科学基金项目(15ZR1429600)

摘　　要：目的基于CT图像对人体颈胸段脊柱C5-T2节段进行三维模型重建，采用有限元方法探究椎弓根螺钉、钛网和钢板等不同内固定器械组合对颈胸段脊柱全脊椎切除（total spondylectomy，TS）术后稳定性的影响及内固定器械的应力分布。方法建立颈胸段脊柱C5-T2节段健康完整模型，并通过与体外实验关节活动度（rangeofmotion，ROM）结果对比验证模型有效性。在健康完整模型基础上，建立颈椎C7节段行TS后的4种重建模型：TM＋AP＋DPS模型（钛网＋前路钢板＋后路双节段椎弓根螺钉固定），TM＋AP＋SPS模型（钛网＋前路钢板＋后路单节段椎弓根螺钉固定）；TM＋DPS模型（钛网＋后路双节段椎弓根螺钉固定）；AP＋DPS模型（前路钢板＋后路双节段椎弓根螺钉固定），并分析各重建模型在前屈、后伸、左右侧弯和左右扭转时的ROM及内固定器械的应力分布情况。结果TS术后重建会大幅度降低重建节段ROM，模型的重建节段ROM均下降超过93％，后路单节段螺钉固定时，钛网出现应力集中现象。结论4种模型重建节段固定效果相近，后路双节段螺钉固定的3种模型中内固定器械应力分布较为平均，模型整体稳定性优于后路单节段固定模型。Objective To establish 3D finite element of human cervicothoracic spine C5-T2 based on CT images, and explore effects on stability of the cervicothoracic spine after total spondylectomy （TS） by using various com- binations of internal fixation devices （pedicle screw, titanium mesh, steel plate）, including the stress distributions on these internal fixation devices. Methods The intact finite element model of cervicothoracic spine C5-T2 was established and validated by comparing the model＇ s range of motion （ROM） with that of other in vitro experi- ments. Then four reconstruction models after TS of cervical spine segment C？ were established： TM ＋ AP ＋ DPS model （titanium mesh ＋ anterior plate ＋ posterior double-segmental pedicle screw）, TM ＋ AP ＋ SPS model （titanium mesh ＋ anterior plate ＋ posterior single-segmental pedicle screw）, TM ＋ DPS model （titanium mesh ＋ posterior double-segmental pedicle screw）, AP ＋ DPS model （anterior plate ＋ posterior double-segmental pedicte screw）. ROM of each reconstruction model under flexion, extension, lateral bending and rotation andstress distributions on these internal fixation devices were then analyzed. Results ROM of the reconstruction segments was greatly reduced by over 93% as compare to that of the intact model. Stress concentration phenom- enon appeared on the titanium mesh in the TM ＋ AP ＋ SPS model. Conclusions The fixation effects of four reconstruction models are similar. Stresses on 3 DPS fixed-models are more evenly distributed, indicating that the overall stability of DPS fixed-model is superior to that of SPS fixed-model.

关 键 词：颈胸段脊柱 全脊椎切除 内固定 应力分布 有限元分析 

分 类 号：R318.01[医药卫生—生物医学工程]