RESUMO
This study aims to compare the mechanical strength of three different posterior-based internal fixation methods for posteromedial tibial plateau fractures. The study utilized 12 tibial plateaus harvested from fresh-frozen cadavers, and the posteromedial fracture fragments were created. The bones were then randomly assigned to one of three fixation methods: two posteroanterior lag screws (LS) size 4.0 mm, posterior buttress plate using a 3.5 mm small dynamic compression plate (DCP), or posterior buttress plate using a 3.5 mm T-shaped plate (TP). Biomechanical testing was performed by applying vertical compression force to the center of the posteromedial fracture fragment until the load to failure (displacement ≥ 3 mm) was reached, and displacement of the fragment was measured using a motion sensor. The data exhibited normal distribution, and one-way analysis of variance (ANOVA) was used to determine the load to failure, followed by Fisher post hoc Least-Significant Difference (LSD) to correct for multiple comparisons. The statistical analysis demonstrated significantly higher mean load to failure values in the T-shaped plate group compared to both the small dynamic compression plate group and the lag screw group (p < 0.05). However, after conducting further post hoc analysis, the observed significant differences were solely between the LS and TP groups (p = 0.021). These findings suggest that the T-shaped plate represents the most effective method for internally fixing posteromedial tibial plateau fractures.