中文摘要：

目的模拟临床手术，探讨Coflex动态稳定装置在下腰椎LS／S1退变性疾病中应用的可行性。方法在第2代中国数字化人体“男性23号”数据集平台上，选取下腰椎骶骨数字模型，运用CAX相关软件建立下腰椎及Coflex应用于下腰椎的3组有限元模型（健康者下腰椎模型、Coflex固定IA／5节段模型及Coflex固定LS／S1节段模型）；根据脊柱三柱加载理论和下腰椎生理运动，采用直立、前屈和后伸3种生理载荷分别进行计算、验证和对照分析。结果建立了健康者下腰椎骶骨有限元模型、Coflex固定L4／5节段有限元对照模型、以及Coflex固定L5／S1节段有限元试验模型。根据3组有限元模型对照试验的稳定性和相容性等各种生物力学指标，发现两种动态内固定方式的下腰椎具有相近的生物力学效果。结论本有限元模型对照试验的设计为研究下腰椎L5／S1节段conex动态固定手术提供了生物力学循证依据，对Coflex植入L5／S1节段这一新手术的临床应用具有指导意义。

英文摘要：

Objective To simulate clinical operation and investigate feasibility of Coflex dynamic device for fixing L5/$1 segment of lower lumbar degenerative diseases. Methods The lower lumbar-sacral digital model was ex- tracted from platform of the second generation of Chinese Digitized Human ＂Male No. 23＂ data set, and three fi- nite element （FE） models （ the model of normal lower lumbar sacrum, L4/5 and L5/SI segment fixed with Coflex） were developed respectively using a series of CAX software. According to the spinal three-column load- ing theory and the lower lumbar physiological behaviors, FE model tests were analyzed, validated and compared under the physiological load of upright standing, anteflexion and extension. Results The FE models of normal lower lumbar sacrum （ Healthy）, Coflex fixed-L4/5 segment （ L4/5）, Coflex fixed-LS/S1 segment （I5/S1） were developed, respectively. Based on biomechanical indexes （stability and compatibility） of the controlled trial for the FE model, the two Coflex-fixed FE models showed similar biomechanical effects for fixing the lower lumbar. Conclusions The controlled trials of FE models provide biomechanical evidence for the fixation of lower lumbar L5/S1 segment by Coflex dynamic device, which is of significance for application of Coflex in fixing L5/S1 seg- ment in clinic.