两种股骨截骨角度对膝关节置换术中股骨假体冠状位对线的影响

Two different femoral resection angles for femoral component coronal alignment in total knee arthroplasty: the influence investigation

[目的]研究两种股骨远端外翻截骨角测定方法在膝关节置换术中对股骨假体对线的影响。[方法]对本院2015年3月~2015年6月由两名主刀医师完成的连续111例共137膝全膝关节置换术进行回顾性研究。两名主刀医师术前计划时在下肢全长X线片上测量股骨远端外翻截骨角度的方法不同,并以此分为两组。第一组利用股骨远端1/3解剖轴与股骨力线轴夹角(DFMA)作为股骨远端外翻截骨角,共71膝;第二组利用股骨解剖轴与股骨力线轴夹角(FMA)进行外翻截骨,共66膝。术后测量标准下肢全长X线片中股骨力线轴与股骨假体远端内外侧髁连线之夹角并比较两组结果的差异。[结果]两组患者的年龄、BMI、术前内翻角度、术前HSS评分、术后HSS评分差异均无统计学意义(P=0.149~0.985)。DFMA组术中所使用的股骨外翻截骨角度实际为6.08°±1.57°,FMA组为4.82°±0.74°,两组截骨角度差异有统计学意义(P<0.05)。DFMA组76.1%的术后股骨假体在0°±2°范围内,显著优于FMA组的51.50%,(P=0.005),并且DFMA组74.60%的术后下肢力线在0°±3°范围内,显著优于FMA组的53.00%,(P=0.008)。DFMA组术后下肢力线角度与FMA组差异无统计学意义(1.60°±2.46°vs 1.98°±3.35°,P=0.458)。[结论]内翻膝使用股骨远端1/3解剖轴与力线轴夹角作为个性化股骨外翻截骨角度,术后股骨假体冠状面位置优于使用股骨解剖轴与力线轴夹角。应用股骨解剖轴线确定股骨外翻截骨角度往往偏小,导致残留膝关节内翻畸形。

[Objective] To investigate the influence of two different femoral valgus correction angles on femoral coronal alignment during total knee arthroplasty （TKA） . [Methods] A consecutive series of 111 patients underwent 137 total knee arthroplasty performed by two surgeons from March 2015 to June 2015. One surgeon used the angle between the distal 1/3 femoral anatomic axis and the femoral mechanical axis （DFMA group, 71 TKA） as femoral valgus correction angle. The other one applied the angle between the femoral anatomic axis and the femoral mechanical axis （FMA group, 66 TKA） as femoral valgus correction angle. All patients received standing AP hip-to-knee X ray radiographs pre- and postoperatively. The angle between the femoral mechanical axis and the distal femoral condylar line was measured and compared between two groups after surgery. [Results] There was no statistical difference in age, BMI, preoperative deformity, preoperative or postoperative HSS score between two groups （P =0,149-0.985） . The mean femoral valgus correction angle was 6.08°±1,57° in DFMA group and 4.82°±0,74° in FMA group, with statistically significant difference （P〈0,05） . A total of 76.1% of femoral components in the DFMA group and 51.5% in the FMA group were within 0°±2°, showing significant difference （P = 005） . A total of 74.6% of llmb alignment in the DFMA group and 53.0% m the FMA group were within 0°±3°, also with significant difference （P = 008） , There was no statistical difference in the mean HKA alignment between two groups （ 1.60°±2.46°vs 1.98°±3.35°, P = 0,458） . [Conclusion] Use of DFMA as femoral resection angle can improve femoral component coronal component better than FMA. The femoral resection angle of FMA often lead to smaller resection angle, resulting a danger of postoperative varus.