Lim Joon-Ryul, Yoon Tae-Hwan, Choi Yun-Rak, Lee Hwan-Mo, Chun Yong-Min
Department of Orthopaedic Surgery, Arthroscopy and Joint Research Institute, Yonsei University College of Medicine, Severance Hospital, Seoul, Korea.
Department of Orthopaedic Surgery, Yonsei University College of Medicine, Severance Hospital, Seoul, Korea.
J Orthop Res. 2021 Sep;39(9):1877-1883. doi: 10.1002/jor.24925. Epub 2020 Dec 1.
The extra-articular distal humerus locking plate (EADHP) is widely used for distal extra-articular diaphyseal humeral fracture fixation. However, it occasionally causes skin prominence and discomfort. The upside-down use of a proximal humerus internal locking system (PHILOS) plate is suggested as an alternative option, but it lacks biomechanical evidence. The purpose of this study was to compare the biomechanical performance between two different fixation methods: the modified use of the PHILOS plate on the anterior cortex versus conventional use of an EADHP on the posterior cortex. Twelve pairs of fresh-frozen cadaveric humeri were used and 7 mm gap osteotomy was performed at 50 mm proximal to the lateral epicondyle to simulate an AO/OTA 12-C1.3 fracture type. Single load to failure was measured after five stiffness tests of the plate-bone constructs in anterior/posterior bending, internal/external torsion, and axial compression. There were no significant differences in metrics between the two groups, except for the load to failure in posterior bending, which was significantly higher for PHILOS (1589.3 ± 234.5) compared to EADHP (1430.1 ± 188.6), p < .023. In conclusion, the modified use of the PHILOS plate showed comparable biomechanical performance compared to the conventional EADHP. The new fixation method offers potential clinical advantages, considering the patient's position and surgical approach at the time of surgery as well as postoperative soft tissue irritation. Therefore, this could be an option for distal humeral extra-articular diaphyseal fracture fixation when the use of EADHP is not suitable or preferred.
肱骨远端关节外锁定钢板（EADHP）广泛用于肱骨远端关节外骨干骨折的固定。然而，它偶尔会导致皮肤隆起和不适。有人建议将肱骨近端内锁定系统（PHILOS）钢板倒置使用作为一种替代选择，但缺乏生物力学证据。本研究的目的是比较两种不同固定方法的生物力学性能：PHILOS钢板在前侧皮质的改良使用与EADHP在后侧皮质的传统使用。使用了12对新鲜冷冻的尸体肱骨，并在外侧髁近端50mm处进行7mm间隙截骨，以模拟AO/OTA 12-C1.3骨折类型。在对钢板-骨结构进行前/后弯曲、内/外扭转和轴向压缩的五次刚度测试后，测量单次破坏载荷。两组之间的指标没有显著差异，除了后弯的破坏载荷，PHILOS组（1589.3±234.5）明显高于EADHP组（1430.1±188.6），p<0.023。总之，PHILOS钢板的改良使用与传统的EADHP相比，显示出相当的生物力学性能。考虑到手术时患者的体位和手术入路以及术后软组织刺激，这种新的固定方法具有潜在的临床优势。因此，当不适合或不首选使用EADHP时，这可能是肱骨远端关节外骨干骨折固定的一种选择。
