SchatzkerⅣ型胫骨平台双髁骨折的CT亚型分类及临床意义

Tibial plateau fractures of Schatzker type Ⅳ with lateral condyles involved： a CT sub-classification and its clinical implications

目的根据CT影像资料将累及双髁的SchatzkerⅣ型胫骨平台骨折进一步进行亚型分类，并探讨该亚型分类方法的临床意义。方法回顾性分析2009年7月至2015年12月收治的47例SchatzkerⅣ型胫骨平台双髁骨折（双髁B型）患者资料：男31例，女16例；年龄21～65岁，平均48岁；均为闭合性骨折。分析患者的X线片及CT影像资料，记录骨折块位置、骨折形态、骨折线走行起止等，根据胫骨平台双髁四象限解剖分区进一步分为4个亚型：A型为全内髁连同部分外髁的劈裂骨折；B型为双后髁骨折，累及后内及后外象限关节面；C型为全内髁伴后外侧胫骨平台关节面骨折；D型为内侧胫骨平台粉碎伴后外侧关节面骨折。临床上根据不同的亚型选择相应的手术方式，并随访治疗效果。结果44例（93．6％）患者的骨折线斜向走行，同时位于矢状面和冠状面，在外侧胫骨平台主要累及后外象限。47例患者根据骨折形态进一步分为4个亚型：A型3例（6．4％），B型20例（42．5％），C型16例（34．1％），D型8例（17．0％）。35例患者术后获12～18个月（平均14个月）随访，骨折愈合及完全负重时间为12～21周（平均15周）。术后12个月美国特种外科医院膝关节评分平均为93分（83～97分），膝关节活动度平均为125°（105°～150°）。结论SchatzkerⅣ型胫骨平台双髁骨折（双髁B型）基于CT的亚型分类，有助于深刻理解骨折形态特征，对手术体位、切口入路、内置入物及固定方式的选择有较好的临床指导意义。

Objective To propose a new sub-classification of the tibial plateau fractures of Schatzker type IV with lateral condylar involvement based on their CT morphology. Methods We collected the CT images of 47 consecutive tibial plateau fractures of Schatzker type Ⅳ with lateral condylar involvement （bicondylar type B） which had been treated at our department from July 2009 to December 2015. They were 31 males and 16 females, from 21 to 65 years of age （average, 48 years）. All the fractures were closed injury. Based on fracture location, fracture type and orientation of fracture line, we proposed 4 sub-types according to the anatomical four quadrants of bicondylar tibial plateau fractures： sub-type A were split fractures of total medial condyle and partial lateral condyle; sub-type B were fractures of bilateral posterior condyles involving articular surfaces of posteromedian and posterolateral quadrants; sub-type C were fractures of total or subtotal medial condyle and posterolateral quadrant; sub-type D were eomminuted fractures of medial condyle involving posterolateral quadrant. The surgical procedures corresponded to our subclassification system. The surgical outcomes were followed up. Results The fracture lines were mostly oblique on both coronal and sagittal planes in 44 cases （93.6%）, involving chiefly the posterolateral quadrant of the lateral tibial plateau. The sub-classification resulted in sub-type A in 3 cases （6. 4% ）, sub-type B in 20 cases （42.5%）, sub-type C in 16 cases （34.1%） and sub-type D in 8 cases （17.0%）. Only 35 patients were followed up for 12 to 18 months （average, 14 months） . Fracture union and full-weight bearing were achieved at 12 to 21weeks （average, 15 weeks） after operation. Their Hospital for Special Surgery scores averaged 93 points （from 83 to 97 points） . The average range of knee motion was 125° （from 105° to 150°） . Conclusions The tibial plateau fractures of Schatzker type IV with lateral condylar involvement （bicondylar type B） can be sub-classified into 4 sub-types. Based on the new subclassification, the complex tibial plateau fractures of Schatzker type Ⅳ can be more thoroughly understood and reasonably treated.