A Locking Plate Designed With Cluster of Head Screws Would Be Biomechanically Superior Than Conventional Buttress Plate For The Fixation of Posteromedial Tibial Plateau Fractures: A Computational Assessment

Abstract Background: Dealing with high-energy fractures of the tibial plateau remains a challenge despite advances in implants, surgical approaches, and imaging methods. Posterior buttress plate is most commonly used implant but the fixation stability is still a challenge. Recently, a newly designed tibial locking plate was introduced that aims to provide better fixation strength for tibial plateau split fracture. This study compared the biomechanical strength of three different posteromedial tibial plateau split fracture fixation methods. Methods: The tibial plateau fractures were simulated using a human tibiae model. Each fracture model was virtually implanted with one of the three following constructs, proximal medial tibial plate (PMT), proximal posterior medial tibial plate (PPMT), and posterior T-shaped buttress plate (TBP). Posteromedial fragment vertical subsidence was measured under 2000 N joint contact force. The maximum Equivalent stress on the bone plate and bone screw and the construct stiffness were determined.Results: The proximal medial tibial plate (PMT) allowed the least posteromedial fragment subsidence and produced higher construct stiffness than each of the other two constructs. However, the proximal posterior medial tibial plate (PPMT) showed higher stiffness than the T-shaped buttress plate (TBP). The maximum Equivalent stress was the smallest for the proximal medial tibial plate (PMT).Conclusion: This study showed that the proximal medial tibial locking plate or proximal posterior medial tibial locking plate were biomechanically more stable fixation methods for posteromedial split tibial plateau fractures.