Morphological characteristics of posterolateral articular fragments in tibial plateau fractures.

Treatment of posterolateral tibial plateau fractures is controversial, and information regarding this specific fracture pattern is lacking. The purpose of this study was to elucidate the frequency and morphological features of posterolateral articular fragments in tibial plateau fractures. A retrospective radiographic and chart review was performed on a consecutive series of patients who sustained tibial plateau fractures between May 2008 and August 2012. The articular surface area, maximum posterior cortical height, sagittal fracture angle, and amount of displacement were measured on computed tomography scans using the Picture and Archiving Communication System. Thirty-six (15%) of 242 injuries demonstrated a posterolateral fracture fragment comprising a mean 14.3% of the articular surface of the total tibial plateau (range, 8% to 32%). Mean major articular fragment angle was 23° (range, 62° to -43°), mean maximum posterior cortical height was 29 mm (range, 18 to 42 mm), and mean sagittal fracture angle was 77° (range, 58° to 97°). The posterolateral plateau articular fracture fragment has morphological characteristics of a conically shaped fragment with a relatively small articular surface area and sagittal fracture angle. Recognizing these morphological features will help the clinician formulate an effective surgical plan.