Department of Trauma Surgery, Orthopaedics and Sports Traumatology, BG Trauma Hospital Hamburg, Bergedorfer Strasse 10, 21033 Hamburg, Germany.
Laboratory for Biomechanics, Department of Orthopedics and Trauma Surgery, University Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
Clin Biomech (Bristol). 2022 May;95:105652. doi: 10.1016/j.clinbiomech.2022.105652. Epub 2022 Apr 22.
Plate osteosynthesis depicts the gold standard to surgically treat pubic symphysis disruptions. However, high rates of implant failure after plate osteosynthesis are reported, probably because of the iatrogenic arthrodesis of this fibrocartilaginous joint. Therefore, flexible implants for treatment of pubic symphysis disruptions appear to be a sensible solution.
In this biomechanical screening study, we designed and investigated a flexible implant, which consists of two plates connected with an ultra-high molecular weight polyethylene fiber cord. We mechanically tested eye splices as a possible fixation method of the cords by performing tensile load to failure tests. Afterwards, we developed a biomechanically appropriate plate design and cord routing between the plates. Finally, we biomechanically tested the flexible implant under tensile and shear loading until failure.
When fixing a 1 mm ultra-high molecular weight polyethylene fiber cord with eye splices, a load at failure of 1570.74 N was detected under tensile loading. None of the eye splices failed but the cords itself ruptured. The load at failure of the designed cord routing in criss-cross technique and fixation within the plates amounts 4742.09 N under tensile and 2699.77 N under shear load.
We developed a novel flexible implant for repair of pubic symphysis disruptions using ultra-high molecular weight polyethylene fiber cords connected to osteosynthesis plates. We identified eye splices as a mechanically optimal fixation method and proved that the ultra-high molecular weight polyethylene fiber cord routing and fixation of the flexible implant clearly withstands physiological forces acting on the pubic symphysis.
钢板内固定被认为是治疗耻骨联合分离的金标准。然而，钢板内固定后植入物失败的发生率很高，这可能是由于这种纤维软骨关节的医源性融合。因此，用于治疗耻骨联合分离的柔性植入物似乎是一种合理的解决方案。
在这项生物力学筛选研究中，我们设计并研究了一种由两块板通过超高分子量聚乙烯纤维绳连接而成的柔性植入物。我们通过进行拉伸破坏试验，对作为绳索固定方法的眼环进行了力学测试。之后，我们开发了一种合适的生物力学板设计和板间绳索布线。最后，我们对柔性植入物进行了拉伸和剪切加载直至破坏的生物力学测试。
用眼环固定 1mm 超高分子量聚乙烯纤维绳时，在拉伸载荷下的破坏载荷为 1570.74N。眼环没有失效，但绳索本身断裂了。采用十字交叉技术布线和在板内固定的设计绳索的破坏载荷在拉伸时为 4742.09N，在剪切时为 2699.77N。
我们使用连接到接骨板的超高分子量聚乙烯纤维绳开发了一种治疗耻骨联合分离的新型柔性植入物。我们确定眼环是一种机械上最优的固定方法，并证明了超高分子量聚乙烯纤维绳布线和柔性植入物的固定能够明显承受耻骨联合上的生理力。
