Koroneos Zachary A, Wee Hwabok, Reid J Spence, Lewis Gregory S
Department of Orthopaedics and Rehabilitation, Penn State College of Medicine, Hershey, Pennsylvania, USA.
Department of Mechanical Engineering, The Pennsylvania State University, University Park, Pennsylvania, USA.
J Orthop Res. 2025 Sep;43(9):1606-1618. doi: 10.1002/jor.26114. Epub 2025 Jun 8.
Bridge plating is commonly used for internal fixation of comminuted fractures. The inner working length between screws has been established as a key parameter controlling postoperative biomechanical stability. However, plate-bone contact may affect these biomechanics in complex ways, and the offset between the plate and bone is variable across surgeries. The objective of this study was to examine the effects of construct and loading parameters on interfragmentary motion and maximum plate stress of bridge plating constructs. Finite element models were developed with variations in inner working length, plate-bone offset, fracture gap size, and loading type and magnitudes. Experiments with synthetic bones were conducted in parallel to support model credibility. Analytical models were also developed based on beam bending and torsion of the plate, assuming rigidity outside the inner working length. Finite element and experimental results of axial and torsional loading scenarios without plate-bone contact confirmed linear relationships between inner working length and interfragmentary motion. Analytical predictions of interfragmentary motion showed very good agreement with the finite element simulations in these scenarios. Conversely, in cases with plate-bone contact, a shorter effective working length was formed, and results were dependent on additional variables such as fracture gap. The study shows how the mechanics of bridge plating can be understood and predicted based on beam theory up to the point of plate-bone contact, and how interfragmentary motions and maximum plate stresses are influenced by the interaction of surgical variables in the presence of plate-bone contact.
桥接钢板常用于粉碎性骨折的内固定。螺钉之间的内部工作长度已被确定为控制术后生物力学稳定性的关键参数。然而，钢板与骨的接触可能以复杂的方式影响这些生物力学，并且钢板与骨之间的偏移在不同手术中是可变的。本研究的目的是研究结构和加载参数对桥接钢板结构的骨折块间运动和最大钢板应力的影响。建立了内部工作长度、钢板与骨的偏移、骨折间隙大小以及加载类型和大小等参数变化的有限元模型。同时进行了合成骨实验以支持模型的可信度。还基于钢板的梁弯曲和扭转建立了分析模型，假设内部工作长度以外为刚性。无钢板与骨接触的轴向和扭转加载情况下的有限元及实验结果证实了内部工作长度与骨折块间运动之间的线性关系。在这些情况下，骨折块间运动的分析预测与有限元模拟结果非常吻合。相反，在有钢板与骨接触的情况下，形成了较短的有效工作长度，结果取决于诸如骨折间隙等其他变量。该研究表明，在钢板与骨接触之前，如何基于梁理论理解和预测桥接钢板力学，以及在存在钢板与骨接触的情况下，手术变量的相互作用如何影响骨折块间运动和最大钢板应力。
