Double plating in Vancouver type B1 periprosthetic proximal femur fractures: A biomechanical study

Periprosthetic hip fractures are an increasing problem in modern orthopedic and trauma surgery. Many options for the operative treatment are available to the surgeon ranging from modern variable angular systems to standard plates, screws, and cerclages. However, there is no gold standard and therefore, the aim of this study, was to investigate the biomechanical characteristics of double plating versus a lateral standard plate in a Vancouver B1 fracture model. Ten 4th generation composite femora were used to implant cementless total hip prosthesis and create Vancouver B1 periprosthetic fractures. Afterwards, the osteotomies were fixed using the locking compression plate in combination with the locking attachment plate (LCP, LAP, DePuy Synthes, Solothurn, Switzerland)-group I. Group II additionally achieved a 5-hole 4.5/5.0mm LCP anteriorly. Each construct was cyclically loaded to failure in axial compression. Axial construct stiffness was 50.87N/mm (SD 1.61) for group I compared to 738.68N/mm (SD 94.8) for group II, this difference was statistically significant (p=0.016). The number of cycles to failure was also significant higher for group II (2,375 vs. 13,000 cycles; p=0.016). Double plating can significantly increase construct stiffness and stability, and thus, is an option in the treatment of complex periprosthetic fractures, in revision surgery and for patients with the inability to partial weight bear. (c) 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:234-239, 2017.