Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Faculty of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran.
Proc Inst Mech Eng H. 2020 Oct;234(10):1129-1138. doi: 10.1177/0954411920941664. Epub 2020 Jul 10.
The goal of this study was to investigate two commonly used methods of fixation of distal metaphyseal tibia fractures, plating and nailing as well as the less frequently employed nailing with Poller screws, from a biomechanical perspective. Despite numerous studies, the best method to repair fractures of tibia the remains up for of debate. This study includes an in vitro experimental phase on human cadaveric tibias followed by a finite element analysis. In the experimental phase, under partial weight-bearing axial loading, the axial stiffness of the bone-implant construct and interfragmentary movements for each of the fixation methods, bone-plate, bone-nail, and bone-nail-Poller screw, were measured and compared with each other. Shear interfragmentary movement and stress distribution in the bone-implant construct for the three mentioned fixation methods were also determined from FE models and compared with each other. Results of in vitro experiments, i.e., the exertion of axial loading on the tibia-plate, tibia-nail, and tibia-nail-Poller screw, showed that utilization of tibia-nail and tibia-nail-Poller screw led to a stiffer bone-implant construct, and consequently, lower interfragmentary movement, compared to the tibia-plate construct ( values for tibia-nail and tibia-nail-Poller screw, and for both axial stiffness and interfragmentary movement, compared to those of tibia-plate construct, were less than 0.05). Numerical analyses showed that nailing produced less undesirable shear interfragmentary movement, compared to the plating, and application of a Poller screw decreased the shear movements, compared to tibia-nail. Furthermore, using the finite element analysis, maximum von Mises stress of adding a screw in tibia-nail, tibia-plate, and tibia-nail-Poller screw, was found to be: 51.5, 78.6, and 60.5 MPa, respectively. The results of this study suggested that from a biomechanical standpoint, nailing both with and without a Poller screw is superior to plating for the treatment of distal tibia fractures.
本研究旨在从生物力学角度探讨治疗胫骨远端干骺端骨折的两种常用方法，即钢板固定和髓内钉固定，以及较少使用的 Poller 螺钉髓内钉固定。尽管已有大量研究，但胫骨骨折的最佳治疗方法仍存在争议。本研究包括对人体尸体胫骨进行体外实验阶段，随后进行有限元分析。在实验阶段，在部分负重轴向加载下，测量并比较了每种固定方法（钢板、髓内钉和髓内钉-Poller 螺钉）的骨-植入物结构的轴向刚度和骨折块间的运动，并与彼此进行比较。还从 FE 模型中确定了三种固定方法的剪切骨折块间运动和骨-植入物结构中的应力分布，并相互比较。体外实验结果，即胫骨-钢板、胫骨-髓内钉和胫骨-髓内钉-Poller 螺钉所承受的轴向载荷表明，与胫骨-钢板结构相比，胫骨-髓内钉和胫骨-髓内钉-Poller 螺钉的使用导致骨-植入物结构更刚硬，从而导致骨折块间的运动更小（胫骨-髓内钉和胫骨-髓内钉-Poller 螺钉与胫骨-钢板结构相比，轴向刚度和骨折块间运动的 值均小于 0.05）。数值分析表明，与钢板固定相比，髓内钉固定产生的剪切骨折块间运动更小，而应用 Poller 螺钉则比胫骨-髓内钉固定产生的剪切运动更小。此外，通过有限元分析，发现胫骨-髓内钉、胫骨-钢板和胫骨-髓内钉-Poller 螺钉中添加螺钉后最大 von Mises 应力分别为：51.5、78.6 和 60.5 MPa。本研究结果表明，从生物力学角度来看，髓内钉固定无论是单独使用还是与 Poller 螺钉联合使用，治疗胫骨远端骨折均优于钢板固定。
