摘要
[目的]研究分析腰骶椎弓根螺钉固定对组配式人工半骨盆假体置换后骨盆与假体生物力学的改变。[方法]建立正常骨盆的三维有限元模型,在相同的加载条件下测量模型的应力分布及位移变化,并与文献进行对比验证。利用验证的正常骨盆有限元模型模拟左侧骨盆Ⅰ+Ⅱ+Ⅲ+Ⅳ区部分骶骨切除,构建人工半骨盆假体置换模型以及联合腰骶椎弓根螺钉固定的半骨盆假体置换模型。加载后分析重建骨盆及假体应力分布及位移特点,比较两种重建模型应力变化较大的8个相同位置的表明最大应力。[结果]建立的骨盆有限元模型外观逼真,几何相似性好,与文献报道相似。重建骨盆健侧应力分布以骶髂关节、髋臼窝及耻骨为主,置换侧以耻骨连接棒、髋臼杯及髂骨固定座为主。联合腰骶椎弓根螺钉固定后8个相同位置的最大应力值不同程度的降低,置换侧位移也相对减小。[结论]联合腰骶椎弓根螺钉固定的组配式人工半骨盆假体重建具有良好的生物力学特性,能缓解置换侧应力集中,降低术后骨盆破坏的风险。
[Objective] To analysis the biomechanical characteristics of the reconstructed pelvis with modular hemi-pelvic prosthesis combined with lumbosacral pedicle screw fixation by finite element method. [Methods] A finite element model of nor- mal pelvis was established. For validation, the model was constrained and loaded to simulate that used in previous biomechani- cal studies. Left pelvic defects in zone I ＋ II ＋llI ＋ IV with partial sacral resection, subsequently pelvic reconstruction with he- mi-pelvic prosthesis replacement, afterward combined with lumbosacral pedicle screw fixation were mimicked in these element models. The stress distribution and displacement characteristics of contralateral pelvis and prosthesis were analyzed, and the stresses of eight identical locations were compared. [Results] The model of normal pelvis was built clearly with good geometric similarity to that reported in the literature. The stress distribution on the uninvolved side of the reconstructed pelvis focused on the sacroiliac joint, acetabular fossa and pubis, whereas the stress on the replaced side concentrated on pubic link rods, acetabu- lar cup and iliac fixation part. After lumbosacral pedicle screw fixation, the stress considerably decreased at the eight identical locations, associated with reduced displacement on the replaced side. [Conclusion] Pelvic reconstruction with modular henri- pelvic prosthesis combined with lumbosacral pedicle screw fixation does improve pelvic biomechanical characteristics, such as alleviating stress concentration and reducing risk of postoperative pelvic collapse.
出处
《中国矫形外科杂志》
CAS
CSCD
北大核心
2017年第24期2269-2273,共5页
Orthopedic Journal of China
基金
上海市科委产学研医项目(编号:12DZ1940205)
上海交通大学医工交叉项目(编号:YG2013MS05)
关键词
骨盆
假体
椎弓根螺钉
有限元
生物力学
pelvis, prosthesis, pedicle screw, finite element, biomechanics
