A biomechanical analysis of internal fixation of complex tibial plateau fractures

Objective: To compare the mechanical stability of fixation of an unstable bicondylar tibial plateau fracture with several different fixation techniques in a cadaveric model. Design: Randomized laboratory investigation using a simulated bicondylar tibial plateau fracture with metaphyseal-diaphyseal dissociation. Setting: Complex tibial plateau fractures were instrumented and tested under ramp and cyclic loading conditions on a servohydraulic materials testing machine. Intervention: Each tibia was instrumented sequentially with a lateral buttress plate, a lateral and a medial buttress plate, and a lateral buttress and an anteromedial antiglide plate for ramp load resting. For cyclic testing, one of the three constructs was used on each specimen. Main Outcome Measurements: Vertical subsidence of the medial tibial plateau was measured in both ramp and cyclic loading in order to evaluate the three internal fixation techniques. Results: No significant difference was measurable between the dual buttress construct and the lateral buttress/anteromedial antiglide construct. However, the lateral buttress plate alone provided significantly less stability. Conclusions: A lateral buttress plate with an anteromedial antiglide plate may provide equally effective fixation as compared with the dual buttress plating technique in complex tibial plateau fractures. This less invasive technique may also be associated with fewer complications due to the lack of soft tissue stripping that is required for its application.