中文摘要：

目的比较经皮骨盆后方张力带钢板和经皮骶髂螺钉固定Denis3类骶骨纵行骨折的术后稳定性和力学相容性，为不同类型骨折的内固定术式选择提供依据。方法采用第2代中国数字化人体“男性第23号”CT和MRI，构建完整骨盆有限元模型，骶骨I、Ⅱ、Ⅲ区纵形骨折伴同侧耻骨上下支骨折的经皮后方张力带钢板内固定有限元模型，以及这3类骨折的经皮骶髂螺钉内固定有限元模型。根据腰骶脊柱三柱加载模式和骶髂关节生理运动模式采用多方案有限元分析及实验验证。结果骶骨I区骨折时，张力带钢板组（P组）的后环与前环器械应力均比骶髂螺钉组（S组）明显增加，骶骨位移也增加。骶骨Ⅱ区骨折时，P组后环与前环器械应力均比s组减小，骶骨位移明显减小。骶骨Ⅲ区骨折时，P组后环与前环器械应力以及骶骨位移均比S组明显减小。结论从内固定术后稳定性、骨折愈合的力学相容性及手术操作的安全性等方面考虑，经皮骶髂螺钉比较适合治疗骶骨I区纵形骨折的垂直不稳定型骨盆，而经皮后方张力带钢板比较适合治疗骶骨Ⅱ区和Ⅲ区纵形骨折的垂直不稳定型骨盆。

英文摘要：

Objective This study aims at comparing and optimizing postoperative stability and biomechanical com- patibility in treating different types of vertically unstable sacrum fractures by using percutaneous posterior-ring tension-band steel plate and percutaneous iliosacral screw. Method Using CT and MR images of the second generation of Chinese digitized human “male No. 23”, the finite element models were developed respectively for two groups of vertical sacrum fractures of Denis I , ]], 11I zone with ipsilateral superior and inferior pubis ramus frac- tures treated with percutaneous posterior-ring tension-band steel plate （P-group） vs percutaneous iliosacral screw （S-group）. The multi-solution finite element analysis and experiment validations were adopted on the basis of lumbosacral spinal three-column loading modes and sacroiliac joint physiologic behaviour. Results When simulating vertical sacrum fractures of Denis 1 zone, von Mises stresses of internal fixation device of posteriorand anterior rings of P-group were significantly increased, while the sacrum displacements were also increased compared to those in S-group. Whereas as simulating vertical sacrum fractures in Denis 11 and IH zones, von Mises stresses of fixator of both rings in P-group were lower than those of S-group, and the sacrum displacements were also remarkably decreased. Conclusions Considering internal fixation stability, mechanical compatibility for fracture healing and surgical procedure security, percutaneous iliosacral screw is more appropriate for the treatment of vertically unstable pelvis fractures with sacrum ｜ zone injury, whereas percutaneous posterior ten- sion-band steel plate is in favor of the treatment of vertically unstable pelvis fractures with sacrum 11 and I11 zone njunes