不同生长棒内固定方式治疗早发性脊柱侧凸的有限元分析  

A finite element analysis on different constructs of growing rods for severe early onset scoliosis

作　　者：藏磊[1] 李永刚[2] 海涌[3] 范宁 杜鹏[5] 袁硕[1] ZANG Lei;LIYong-gang;HAIYong;FAN Ning;DU Peng;YUAN Shuo(Orthopedic Department,Jingxi Part,Chaoyang Hospital,Capital Medical University,Beijing 100043,China;Department of Orthopaedic,Capital Medical University,Beijing 100043,China;Department of Emergency,Chaoyang Hospital,Capital Medical University,Beijing 100020,China;Orthopedic Department,Fuxing Hospital,Capital Medical Universi- ty,Beijing 100043,China;The Second Department of Orthopaedic,Shunyi District Hospital,Beijing 101300,China)

机构地区：[1]首都医科大学附属北京朝阳医院京西院区骨科,北京100043 [2]首都医科大学附属复兴医院骨科,北京100045 [3]首都医科大学附属北京朝阳医院骨科,北京100020 [4]北京市顺义区医院骨二科,北京101300 [5]首都医科大学附属北京朝阳医院急诊科,北京100020

出　　处：《中国矫形外科杂志》2019年第1期79-85,共7页Orthopedic Journal of China

基　　金：国家自然科学基金项目(编号:81372008);首都医科大学附属北京朝阳医院京西培育课题(编号:JXPY201607)

摘　　要：[目的]探讨不同生长棒内固定方式治疗重度早发性脊柱侧凸的有限元生物力学差异及最佳内固定方式。[方法]选取1例接受单侧生长棒矫形手术的7岁男性EOS患者,并进行层厚为0.625mm的超薄螺旋CT扫描。通过有限元建模方法分别建立该患儿术前(M1)及术后(M2,单侧生长棒和4枚螺钉)的有限元模型,并模拟建立其他4种生长棒内固定方式的有限元模型(M3,单侧生长棒和8枚螺钉;M4,单侧生长棒、3枚螺钉和1枚椎板钩;M5,双侧生长棒和8枚螺钉;M6,双侧生长棒、6枚螺钉和2枚椎板钩)。收集各有限元模型的椎体、椎弓根螺钉、椎板钩及生长棒的生物力学数值并进行对比分析。[结果] M5、M6、M3模型依次具有最佳的生物力学性能。同M2、M3、M4模型相比,M5和M6模型具有更小的椎体位移及应力和更大的生长棒应力。当椎弓根螺钉更换为椎板钩时,椎体位移及应力、其他螺钉及生长棒的应力均会增加。[结论]螺钉固定的双侧生长棒系统最为坚固;螺钉-椎板钩固定系统可以降低内置物的僵硬度;单侧生长棒系统通过增加螺钉数量可以改善其生物力学性能。[Objective] To explore the best growing rod approach for severe early onset scoliosis(EOS) by comparison of biomechanical characteristics of different growing rods. [Methods] A seven-year-old male child who accepted surgical correction with 4 pedicle screws and a single rod for severe EOS was selected as the subject of this study. Based on spiral computed tomography(CT) scanning performed in 0.625 mm thick slices, finite element models of the preoperative state(M1, the original spine state) and postoperative state(M2, spine corrected with 4 pedicle screws and an unilateral rod) of the child were created,subsequently, 4 models of different corrections were simulated by finite element modeling, including M3 with a single rod and 8 screws, M4 with a single rod, 3 screws and 1 hook, M5 with two rods and 8 screws, as well as M6 with 2 rods, 6 screws and 2 hooks. Biomechanical characteristics of the pedicle screw, lamina hook, and growing rod were measured and compared among the 6 models. [Results] In term of biomechanical properties, the best biomechanical efficiency was proved in sequence of the M5>M6>M3. The M5 and M6 had smaller vertebral displacement and stress, while larger rod.s stress than those of the M2, M3 and M4. The vertebral displacement and stress, as well as screw and rod.s stress increased as screw change to hook. [Conclusion] Dual rods combined with pedicle screws are the best construct for correction of EOS. The screw-hook combination reduces the rigidity of the internal fixation, whereas the biomechanical efficiency can be improved by increase of screw fixation in the single rod system.

关 键 词：早发性脊柱侧凸 治疗 有限元 生物力学 

分 类 号：R682.3[医药卫生—骨科学]