Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON M4N 3M5, Canada; Holland Bone and Joint Research Program, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada.
Department of Surgery, Division of Orthopaedics, University of Toronto, Toronto, ON M4N 3M5, Canada; Holland Bone and Joint Research Program, Sunnybrook Research Institute, Toronto, ON M4N 3M5, Canada.
J Biomech Eng. 2021 Jul 1;143(7). doi: 10.1115/1.4050459.
The threshold for surgical stabilization for an open-book pelvic fracture is not well defined. The purpose of this research was to validate the biomechanical behavior of a specimen-specific pelvic finite element (FE) model with an open-book fracture with the biomechanical behavior of a cadaveric pelvis in double leg stance configuration under physiologic loading, and to utilize the validated model to compare open book versus intact strain patterns during gait. A cadaveric pelvis was experimentally tested under compressive loading in double leg stance, intact, and with a simulated open-book fracture. An intact FE model of this specimen was reanalyzed with an equivalent simulated open-book fracture. Comparison of the FE generated and experimentally measured strains yielded an R2 value of 0.92 for the open-book fracture configuration. Strain patterns in the intact and fractured models were compared throughout the gait cycle. In double leg stance and heel-strike/heel-off models, tensile strains decreased, especially in the pubic ramus contralateral to the injury, and compressive strains increased in the sacroiliac region of the injured side. In the midstance/midswing gait configuration, higher tensile and compressive FE strains were observed on the midstance side of the fractured versus intact model and decreased along the superior and inferior pubic rami and ischium, with midswing side strains reduced almost to zero in the fractured model. Identified in silico patterns align with clinical understanding of open-book fracture pathology suggesting future potential of FE models to quantify instability and optimize fixation strategies.
对于骨盆开放性骨折的手术稳定阈值尚未明确定义。本研究的目的是验证具有开放性骨折的特定骨盆有限元（FE）模型的生物力学行为与在生理负荷下双下肢站立配置下尸体骨盆的生物力学行为是否一致，并利用经过验证的模型比较步态过程中开放性骨折与完整骨盆的应变模式。对尸体骨盆进行了在双下肢站立、完整和模拟开放性骨折下的压缩加载实验。对该标本的完整 FE 模型进行了重新分析，具有等效模拟的开放性骨折。FE 生成和实验测量应变的比较产生了开放性骨折构型的 R2 值为 0.92。在整个步态周期中比较了完整和骨折模型的应变模式。在双下肢站立和足跟触地/离地模型中，拉伸应变减小，特别是在损伤对侧的耻骨支，而损伤侧的骶髂区域的压缩应变增加。在中足/中间摆动步态配置中，与完整模型相比，骨折模型的中足侧观察到更高的拉伸和压缩 FE 应变，并沿着耻骨上支和坐骨减小，而在骨折模型中，中足侧的应变几乎减小到零。在计算机中确定的模式与开放性骨折病理的临床理解一致，这表明 FE 模型将来有可能量化不稳定性并优化固定策略。
