Plating treatment for tibial plateau fractures:: a biomechanical comparison of buttress and tension band positions

The load tolerance of conventional plate treatment for bicondylar tibial plateau fractures with the buttress and the tension band positions was compared from biomechanical viewpoints. Fourteen left synthetic tibiae divided into two groups were tested. T-plates in the buttress group were placed on the medial tibial subcondyle and T-plates in the tension band group were placed on the lateral tibial subcondyle. All specimens were evaluated with a Material Testing System (MTS) machine. A linear variance displacement transducer gauge was placed on the medial tibial subcondyle. The anatomic axis of the synthetic femur and the tibia was maintained at 6 degrees varus in the frontal plane. The MTS actuator was set to increase displacement at 3 mm/min. All specimens were evaluated to failure. The relative motion and the ultimate failure load (UFL) between both groups were compared. The buttress group had significantly less displacement than the tension band group following the incrementally increased loading (p < 0.001). At failure, the buttress group also had a higher UFL (p < 0.001) and less displacement (p = 0.009) than the tension band group. All medial tibial condylar fragments achieved improved stabilization from the medial aspect of the proximal tibia by conventional plates. When conventional plates cannot be placed medially due to skin ailments, lateral placement of conventional plates may have the insufficient stability. Protected weight bearing should be followed strictly.