目的：利用有限元模型分析脊柱凸成形术（ PKP）治疗后骨折椎体及邻近椎体的应力变化，探讨PKP治疗后骨折椎体强度与邻近椎体骨折的关系。方法选择因L2椎体骨质疏松性骨折行PKP治疗、并随访1年半的患者1例，根据治疗前后患者的腰椎CT资料，构建椎体生物力学的有限元模型，对第L1～L3椎体在前后屈曲、左右侧屈及旋转状态下进行应力载荷实验，观察L2及邻近L1、L3椎体终板、椎体骨小梁、椎体骨水泥所承受的应力改变情况。结果术后L2椎体终板、椎体骨水泥在前屈、后伸、左侧屈、右侧屈状态下的应力值均高于术前（ P＜0．05）。 PKP前后椎体骨小梁各种运动状态下的应力值差异无统计学意义。 L1、L3椎体PKP前后各种模拟状态下应力变化差异无统计学意义。结论 PKP治疗可以有效增强骨折椎体的强度，提高椎体的载荷，且邻近椎体不会出现应力变化，对邻近椎体不会造成不良影响。%Objective To analyze the stress change of fractured vertebral body and its adjacent vertebral bodies after spinal projection angioplasty ( PKP) by using the finite element model , and to discuss the relationship between fractured vertebral strength and the adjacent vertebral body fractures .Methods One Patient with osteoporotic fracture of lumbar vertebral body 2 in 2013 treated with PKP and followed up for 1 year was selected .According to the patient's lumbar spine CT data before and after treatment , we established the finite element model of vertebral biomechanics , and performed the stress loading test on the lumbar vertebrae 1, 2 and 3 under before and after buckling , right and left lateral flexion and rota-tion.Then we observed the stress changes of vertebral endplate , vertebral trabecular bone and vertebral bone cement of lumbar vertebral body 2 and its adjacent vertebrae 1 and 3.Results The stress values of vertebral endplate and vertebral bone cement of lumbar vertebral body 2 under the state of anterior flexion , posterior extension , left and right flexion were higher than those before the operation (P<0.05), but there was no statistically difference in the stress change of vertebral trabecular bone before and after treatment as well as the stress change of vertebrae 1 and 3 under all those various simulated states before and after PKP .Conclusion PKP can effectively enhance the strength of fractured vertebrae and improve ver-tebral loading.Meanwhile, the stress change does not appear on the adjacent vertebrae and it causes no adverse effects .
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