Different patterns of tibial plateau fractures associated with hyperextension injuries of the knee with or without varus/valgus component

This study aims to introduce a morphological classification of hyperextension tibial plateau fractures based on CT scans and to reveal the correlation between the anterior compression and posterior tension fractures. From January 2015 to January 2019, 37 patients with hyperextension tibial plateau fractures were studied retrospectively. Based on this classification, the fractures were divided into 2 groups: group A had anterolateral or anteromedial compression fractures while group B had both. Three observers classified the fractures and recorded the morphology and incidences of posterior plateau fractures and proximal fibular fractures. All 37 fractures were allocated to group A (n = 15; 40%) and B (n = 22; 60%). Of the posterior tibial plateau fractures, 10 (27%) fractures were defined as partial and 27 (73%) as total. Of the 37 fractures, 18 (49%) proximal fibular avulsion fractures were observed. There was a significant difference between groups A and B regarding the incidence of total posterior tibial plateau fractures (P < .05). However, there was no significant difference between the incidence of proximal fibular avulsion fractures in the 2 groups or the combined and non-combined type fractures in group B (P > .05). Hyperextension tibial plateau fractures with a decreased posterior slope angle always involve both the anteromedial and anterolateral plateaus. This CT-based classification may improve the understanding of fracture features and is helpful for planning treatment.