Kritsaneephaiboon Apipop, Wanchat Sujin, Khongkanin Thammaphong, Kwanyuang Atichart, Srewaradachpisal Satta, Dissaneewate Kantapon, Orapiriyakul Wich
Department of Orthopedics, Faculty of Medicine, Prince of Songkla University, Songkhla, Thailand.
Department of Mechanical Engineering, Faculty of Engineering at Sriracha, Kasetsart University, Sriracha, Chonburi, Thailand.
Front Bioeng Biotechnol. 2025 Oct 1;13:1672989. doi: 10.3389/fbioe.2025.1672989. eCollection 2025.
The locking compression plate extra-articular distal humeral plate (EADHP) is an anatomically pre-contoured plate that is used for extra-articular distal humeral fractures. However, there is currently no standard criterion for the internal fixation of this type of fracture. Moreover, the anterior reverse proximal humeral internal locking system (PHILOS) plate (ARPP) has been clinically applied as a new internal-fixation plate without testing in biomechanical studies. We aimed to compare the biomechanical properties of ARPP and EADHP for the definitive fixation of extra-articular distal humeral fractures.
Eighteen composite humerus bones were cut at the distal humerus using an electrical saw to generate a fracture gap. Internal fixation via the ARPP or EADHP was performed following standard techniques. An Instron testing machine (Instron 8872) was used to evaluate biomechanical properties by applying bending torque, axial force, and torsional torque.
Fixations with both ARPP and EADHP could withstand forces that exceeded the physiological forces (200 N). Under axial compression, ARPP constructs demonstrated greater stiffness (668.9 ± 120.7 N/mm vs 171.2 ± 45.4 N/mm) and higher maximal load-to-failure (2,092.6 ± 305.2 N vs 907.0 ± 56.5 N) compared with EADHP, although these differences were not statistically significant. During anterior bending, ARPP provided significantly higher stiffness (17.8 ± 2.0 N/mm vs 13.9 ± 1.0 N/mm, = 0.041), whereas EADHP showed a higher but non-significant load-to-failure. Under torsional loading, ARPP tended to exhibit greater stiffness in both external and internal rotation, as well as higher load-to-failure (31.1 ± 0.8 N m vs 26.0 ± 4.4 N m), but without statistical significance.
ARPP demonstrated superior bending stiffness compared with the EADHP, while both constructs performed equivalently in axial compression and torsion. Therefore, ARPP can serve as an alternative internal-fixation method for extra-articular distal humeral fractures.
锁定加压钢板的肱骨远端关节外钢板（EADHP）是一种按解剖结构预塑形的钢板，用于肱骨远端关节外骨折。然而，目前对于此类骨折的内固定尚无标准规范。此外，肱骨近端前侧反向锁定接骨板系统（PHILOS）钢板（ARPP）已在临床上作为一种新型内固定钢板应用，但尚未进行生物力学研究测试。我们旨在比较ARPP和EADHP在肱骨远端关节外骨折确定性固定方面的生物力学性能。
使用电锯在肱骨远端将18块复合肱骨切断以形成骨折间隙。按照标准技术通过ARPP或EADHP进行内固定。使用英斯特朗测试机（Instron 8872）通过施加弯曲扭矩、轴向力和扭转扭矩来评估生物力学性能。
ARPP和EADHP固定均能承受超过生理力（200 N）的力量。在轴向压缩下，与EADHP相比，ARPP构建物表现出更大的刚度（668.9±120.7 N/mm对171.2±45.4 N/mm）和更高的最大破坏载荷（2092.6±305.2 N对907.0±56.5 N），尽管这些差异无统计学意义。在前侧弯曲过程中，ARPP提供了显著更高的刚度（17.8±2.0 N/mm对13.9±1.0 N/mm，P = 0.041），而EADHP显示出更高但无统计学意义的破坏载荷。在扭转加载下，ARPP在内外旋转时均倾向于表现出更大的刚度，以及更高的破坏载荷（31.1±0.8 N·m对26.0±4.4 N·m），但无统计学意义。
与EADHP相比，ARPP表现出更好的弯曲刚度，而两种构建物在轴向压缩和扭转方面表现相当。因此，ARPP可作为肱骨远端关节外骨折的一种替代内固定方法。
