Biomechanical superiority of locking plate designed with cluster of head screws compared to conventional buttress plate for fixation of posteromedial tibial plateau fractures: A computational assessment

Purpose Dealing with high-energy fractures of the tibial plateau remains a challenge despite advances in implants, surgical approaches, and imaging methods. It is difficult to achieve sufficient fixation stability of a posterior T-shaped buttress (PTB) plate, the most commonly used implant. A tibial locking plate, called the proximal posterior medial tibial (PPMT) plate, that aims to improve fixation strength for tibial plateau split fractures was recently introduced. This study evaluates the biomechanical strength of this plate and compares it to that of a proximal medial tibial (PMT) plate and a PTB plate. Methods Tibial plateau fractures were simulated using a human tibia model. Either a PMT, PPMT, or PTB plate was virtually implanted into each fracture model. The posteromedial fragment vertical subsidence was measured under a 2000-N joint contact force. The maximum equivalent stress on the bone plate and bone screw and the construct stiffness were determined. Results The PMT plate allowed the least posteromedial fragment subsidence and produced the highest construct stiffness. The PPMT plate showed higher stiffness than that of the PTB plate. The maximum equivalent stress was the smallest for the PMT plate. Conclusion This study showed that PMT and PPMT plates are the most biomechanically stable fixation constructs for posteromedial split tibial plateau fractures.