胫骨平台后外侧骨折三种入路的解剖学研究

An anatomical study of three surgical approaches for posterolateral tibial plateau fracture

目的通过尸体标本研究分析比较胫骨平台后外侧骨折3种外侧手术入路的特点。方法取8具成人新鲜冰冻膝关节标本，每具标本分别采用腓骨头上入路（A组，n=8）、腓骨头二分截骨入路（B组，n=8）及股骨外侧髁截骨入路（C组，n=8），测量每组中腓骨头上方结构向后牵开的距离和牵开后胫骨髁增加的显露面积。制作胫骨平台后外侧劈裂骨折模型，观察复位及固定是否易于操作。结果A组、B组、C组膝关节标本腓骨头上方结构向后方牵开距离平均分别为（10．61±0．97）、（15．41±1．05）、（20．72±1．35）mm，向后牵开腓骨头上方结构后增加显露的面积平均分别为（107．55±13．89）、（155．86±10．74）、（197．46±13．52）mm^2，以上项目三组间比较差异均有统计学意义（P〈0．05）。A组不方便从胫骨平台后外侧髁的后方直视下处理后侧壁；B组、C组均可从后方直视下操作，尤以C组显露最佳，操作最为方便。结论三种入路均可用于胫骨平台后外侧骨折的复位及固定，采用腓骨头上入路显露范围最小，不便处理胫骨平台后外侧髁的后壁，但手术创伤最小。与腓骨头上入路比较，腓骨头二分截骨入路及股骨外侧髁截骨入路显露更充分，复位固定更方便，但手术创伤稍大。

Objective To compare 3 lateral surgical approaches （supra fibular head approach, digastric fibular head osteotomy approach, and combined lateral femoral epieondylar osteotomy and submeniscal approach） in exposing the posterolateral tibia plateau in cadaveric specimens. Methods The above 3 published surgical approaches - supra-fibular-head approach （group A, n = 8）, digastric fibular head osteotomy approach （group B, n = 8）, and lateral femoral epicondylar osteotomy approach （group C, n = 8） - were performed in 8 fresh-frozen cadavers. Once exposure of the posterolateral tibia plateau was achieved in each specimen, the backward pull distance of the structures above the fibular head and the exposure area of tibial condyle after retraction were measured. The model of posterolateral splitting fracture of the tibial plateau was established to observe the manipulative difficulties in reduction and fixation of the posterolateral tibial plateau fracture. Results The backward pull distance of the structures above the fibular head was 10. 61 ±0. 97 mm, 15.41± 1.05 ram, and 20. 72 ± 1.35 mm in groups A, B and C respectively while the exposure area after retraction was 107.55 ± 13.89 mm2, 155.86±10.74 mm^2, and 197.46 ± 13.52 mm^2 in the 3 groups respectively, showing statistically significant differences between groups （ P 〈 0. 05）. It was not convenient for the surgical approach in group A to process the posterior wall of posterolateral tibial plateau under direct vision while operation under direct posterior vision could be done in groups B and C, especially in group C where the operation was the most convenient. Conclusions All the 3 approaches can be used for reduction and fixation of the posterolateral tibial plateau fracture. The supra-fibular-head approach gives the smallest exposure range which is inconvenient for treatment of the posterior wall of the posterolateral condyle of the tibial plateau. The digastric fibular head osteotomy approach and lateral femoral epicondylar osteotomy approach provide larger exposure ranges which facilitate convenient reduction and fixation but lead to slightly larger operative trauma.