目的 建立腰椎椎弓峡部裂三维有限元模型，通过与生物力学实验比较进行有效性验证。方法 利用临床1例腰椎椎弓峡部裂病例影像学资料，采用Simpleware建模软件分别模拟下腰椎骨性结构、椎间盘组织，并在Ansys软件附加腰椎相关韧带和关节囊，建立L5双侧椎弓峡部裂三维有限元模型，并通过体外力学实验结果验证模型有效性。结果 重建模型构建了椎体皮质骨、松质骨、腰椎关节突关节、椎弓根、椎板、横突、棘突等骨性结构，还构建了纤维环、髓核、上下终板组织，并成功附加了前纵、后纵韧带、黄韧带、棘上、棘间韧带以及关节突的关节囊。模型共计有 281261 个节点和 661150 个单元。腰椎椎弓峡部裂重建成功。通过与体外生物力学在不同工况下L4下关节突、L5上、下关节突、S1上关节突应力/应变趋势以及L4下关节突内外侧力学应力/应变趋势比较，验证了模型的有效性。结论 建立了下腰椎椎弓峡部裂的三维有限元模型，此模型可以用来进一步实施有关峡部裂治疗的力学研究。

Objectives To construct three-dimensional finite element model of lumbar spondylolysis, then to verify its validity by comparison of biomechanics in vitro. Methods According to the radiological data of a patient with lumbar spondylolysis, the bone and intervertebral disc of L4-S1 were reconstructed by Simpleware software. The lumbar attaching ligaments and articular capsule were added into simulating model by Ansys software. Finally, the three-dimensional finite element model of lumbar spondylolysis was simulated successfully, and validated by lumbar spondylolysis biomechanical experiment in vitro. Results The reconstruction of digital model is contained of the bones of lumbar spine which includes of vertebral cortical bone, cancellous bone, facet joint, pedicle, lamina, transverse process and spinous process,as well as annulus fibrosus, nucleus pulposus,superior and inferior end-plates. Besides, anterior and posterior longitudinal ligaments, flavum ligament, supraspinal and interspinal ligaments and articular capsule of facet joint are also attached. The model consisted of 281,261 nodes and 661,150 elements. Imitation of spondylolysis is well done in this model. The validity of the model is verify by comparison of the results of biomechanics in vitro which involved in the trends under loading of stress/strain of L4 inferior facet process, L5 superior and inferior facet process, S1 superior facet process and the trend of stress/strain of lateral and medial L4 inferior facet process. Conclusions Lumbar spondylolysis is reconstructed to three-dimensional model using finite element analysis, and can be further used in the research of biomechanics of lumbar spondylolysis.

浙江省杭州市科技发展项目(20080333B11)