Most bone fractures heal following implant fixation. However, healing complications may still occur in approximately 10% of the cases, whereof a significant portion can be attributed to unfavorable mechanical conditions at the fracture site. Moreover, state-of-the-art plates are prone to catastrophic failure from either excessive loading in the early post-operative phase or due to fatigue in combination with inadequate healing and load sharing in the late phase. A new plating concept, called biphasic plating, was proposed by ARI in collaboration with QUT (Brisbane, Australia) to enhance the existing treatment modalities of locked plating by redesigning the current bone plate. The biphasic plating concept was proven by mechanical testing and animal experiments. Robust callus formation was demonstrated in a sheep tibia defect model under varying fracture conditions and changing functional loading using a specially designed biphasic plate for sheep (Project 2Pinvivo).
To develop and obtain CE Mark of a biphasic anatomical plate for distal femur fractures as a pilot implant and to collect clinical evidence demonstrating the concept feasibility.
Several activities regarding usability, performance and biocompatibility of the biphasic plate have taken place. The dynamic feature of the plate was redesigned for improved manufacturability. Mechanical testing of prototype plates demonstrated their more than double ultimate strength and more than 4 times longer fatigue life compared to a conventional LCP for the distal femur. Key opinion leaders have tested and approved the implant design in a wet lab. Design freeze was given by end of 2019, leading into verification and validation activities in the coming year and, hence, towards first applications in clinics.
Gurung R, Windolf M, Schwyn R, Zeiter S, Epari D, Hofmann-Fliri L. Novel dynamic plating concept to improve the biomechanics of internal fixation. 2019. AO TAP Scientific Congress, Taipei, Taiwan (oral, best paper award).
Hofmann-Fliri L, Epari D, Schwyn R, Zeiter S, Windolf M. Biphasic Plating – In vivo study on a novel fixation concept to enhance mechanobiological fracture healing. 2019. EORS, Maastricht, Netherlands (oral).
Windolf M, Epari D. Biphasic bone plate. CH01515/19 (Patent)
Epari DR, Gurung R, Hofmann-Fliri L, Schwyn R, Schuetz M, Windolf M. Biphasic plating improves the mechanical performance of locked plating for distal femur fractures. J Biomech. 2021;115:110192. https://doi.org/10.1016/j.jbiomech.2020.110192
Epari D (Prof), Queensland University of Technology, Brisbane, Australia
Schütz M (Prof), Jamieson Trauma Institute, Brisbane, Australia