骶骨切除术后四棒内固定方式重建腰骶部的三维有限元分析  

finite element analysis of lumbosacral reconstruction with a novel four-rod fixation system

作　　者：李全[1] 孙伟[1] 刘俊健[1] 蔡郑东[1] 

机构地区：[1]同济大学附属第十人民医院骨科,上海200072

出　　处：《中华骨科杂志》2011年第6期686-691,共6页Chinese Journal of Orthopaedics

摘　　要：目的分析骶骨切除术后四棒内固定方式重建腰骶部的生物力学特点。方法利用CT图像建立骶骨次全切除和全骶骨切除有限元模型。在次全切除模型上比较四棒内固定方式与改良Galveston技术重建时L3椎体在垂直压缩、前屈、后伸、左侧弯和右旋工况下的活动范围及内固定器械最大应力值。在全切除模型上比较两种重建方式在垂直压缩工况下L3椎体的活动范围和内固定器械最大应力值。结果（1）在次全切除模型上，四棒内固定后L3椎体在各种工况下的活动范围分别为4．2mm、0．49°、0．49°、0．24°和0．26°，改良Galveston技术重建后分别为5．5mm、0．74°、0．74°、0．27°和0．30°。四棒内固定后各种工况下器械最大应力值分别为810．7、148．0、148．0、134．6、14．4Mpa，改良Galveston技术重建后分别为655．0、109．9、109．9、119．1、11．4MPa。（2）在全切除模型上，四棒内固定后垂直压力下L3椎体位移和器械最大应力值分别为10．9mm和2172MPa，改良Galveston技术重建后分别为49．1mm和4325MPa。结论与改良Galveston技术相比，四棒内固定方式重建腰骶部具有较强的刚度。在全骶骨切除且不行腰骶部植骨时，四棒内固定方式具有较小的最大应力值，可降低内固定器械早期失败的风险。但在骶骨次全切除或行腰骶部植骨时，其应力遮挡效应明显增加。Objective To analysis the biomechanical properties of four-rod fixation system for lum- bosacral reconstruction after sacrectomy. Methods Two finite element models of lumbosacral area were established according to pelvic CT images： a subtotal sacrectomy model and a total sacrectomy model. The range of motion of L3 vertebral body and max yon Mise stress of instruments of a novel four-rod fixation system were evaluated and compared with those of modified Galveston technique （MGT） under conditions of vertical compression （925 N）, inflexion （10 N＇m）, extension （10 N ＇m）, left bending （10 N＇m）, and right rotation （10 N,m）, using subtotal sacrectomy model. And using total sacrectomy model, the range of motion of L3 vertebral body and max von Mise stress of instruments of the four-rod fixation system were evaluated and compared with those of MGT under vertical compression. Results In subtotal sacrectomy model, the range of motion of L3 vertebral body in the four-red fixation system were 4.2 mm, 0.49°, 0.49°, 0.24° and 0.26° compared to 5.5 mm, 0.74°, 0.74°, 0.27° and 0.30° in the MGT. The max von Mise stress of instruments in the four-rod fixation system were 810.7, 148.0, 148.0, 134.6 and 14.4 MPa, compared to 655.0, 109.9, 109.9, 119.1 and 11.4 MPa in the MGT. In total sacrectomy model under vertical compression, the range of motion of L3 vertebral body and max von Mise stress of instruments in the four-rod fixation system were 10.9 mm and 2172 MPa compared to 49.1 mm and 4325 MPa in the MGT. Conclusion Comparing with the MGT, the four-rod fixation system was stiffer and showed a significant increase in the stability of lumbosacral area. When total sacrectomy without bone graft were performed, the max stress of the four-rod fixation system was much lower than that of the MGT, which means smaller risk of instrument failure. When subtotal sacrectomy or bone graft were performed, despite better stability, the higher stress shielding-effect of the four-rod fixation system might be u

关 键 词：骶骨 骨肿瘤 有限元分析 内固定器 

分 类 号：R687.3[医药卫生—骨科学]