A CT study on the morphology characteristics of posterolateral tibial plateau fractures / 中华骨科杂志

ABSTRACT

Objective To evaluate the frequency and morphological characteristics of the posterolateral articular fracture in tibial plateau fractures.Methods A retrospective analysis of CT images and clinical data was taken among 309 cases of tibial plateau fractures from 2008 May to 2013 January.There are total 264 patients were recorded excluding 45 cases with which the CT image is missing or not compatible with the medical Picture Archiving and Communication Systems (PACS).To determine the occurrence rate of the posterolateral articular fracture in tibial plateau fractures and measure morphological parameters such as the axial angle of fracture line,articular surface area,sagittal fracture angle,fracture height,and amount of displacement.Results 39 cases of posterolateral articular fragments were found in 264 cases of tibial plateau fractures with the 14.8％ incidence (39/264).There were 18 males and 21 females,aged from 31-70 years (mean,52 years).17 left cases and 22 right cases.The mechanism of injury were traffic accident in 22 patients,blow by a heavy object in 2 patients,a fall in 11 patients,and other causes (unknown) in 4 patients.The posterolateral plateau articular fracture fragment has morphological characteristics of a conical shape fragment and the major articular fragment angle was 22° (range,-43°-62°),and an average accounted for 14.1％ of the articular surface of the total tibial plateau (range,8％-32％).The posterolateral fragment exhibits a vertical fracture pattern and an average sagittal fracture angle was 76° (range,58°-97°),suggestive of shear instability and vertical displacement.Maximum posterior cortical height was 28 mm (range,18-42 mm),and average size of the displacement was 10.48 mm (range,2-19 mm).Conclusion The posterolateral plateau articular fracture fragment has morphological characteristics of a conical shape fragment,relative small articular surface area and sagittal fracture angle.