胫骨后外侧平台骨折的CT形态学研究

摘要

目的 探讨胫骨后外侧平台关节面骨折在胫骨平台骨折中的发生率及其形态学特点.方法 回顾性分析2008年5月至2013年1月309例胫骨平台骨折患者的CT图像及临床资料,其中45例CT图像缺失或不兼容医学影像存储和传输(PACS)系统予排除,共纳入264例患者资料.确定胫骨平台后外侧象限关节面骨折块在胫骨平台骨折中的发生率并测量其骨折线的轴向角度、受累面积、矢状位角度、骨折块高度及移位程度等形态学参数.结果 在264例胫骨平台骨折中,共检测到39例胫骨平台骨折存在后外侧象限关节面骨折块,在胫骨平台骨折中的发生率为14.8％(39/264).其中男18例,女21例;年龄31～70岁,平均52岁;左侧17例,右侧22例.致伤原因:交通伤22例,重物砸伤2例,摔伤11例,受伤原因不明4例.后外侧象限关节面骨折块的骨折线偏于冠状位,骨折线轴向角度为-43°～62°,平均22°;受累的后外侧骨折块面积占整个胫骨平台面积的8％～32％,平均14.1％;后外侧平台骨折块的矢状位角度为58°～97°,平均76°,提示该骨折块在垂直剪切应力下易发生移位;后外侧骨折块的高度为18～42 mm,平均28 mm;后外侧髁骨折块平均移位2～19 mm,平均10.48 mm.结论 胫骨平台骨折累及后外侧平台关节面的发生率为14.8％;胫骨后外侧平台关节面的骨折线偏于冠状位且矢状位角度较大,骨折块所累及的关节面面积较小.%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.