人体膝关节股骨后髁角度的MRI测量

Femoral posterior condylar angle of human knee joint: magnetic resonance imaging measurement

背景:全膝关节置换过程中股骨假体旋转力线良好非常重要,研究显示后髁角度是确定力线的重要依据,后髁角度为股骨后髁轴与股骨手术髁上轴之间角度,MRI测量可清晰显示后髁软骨、外上髁突起及内上髁凹陷,从而保证测量数据的准确。目的:测量保定北部地区人群中膝关节后髁角度,为临床实施全膝关节置换过程中确定股骨假体旋转力线提供影像学依据。方法:应用核磁共振机对入选中青年人群膝关节进行扫描,取膝关节伸直中立位,扫描平面垂直于膝关节机械轴,选择T1像上最佳膝关节轴位平面,由两名观察者独自分析图像,通过Bravo viewer 6.0影像软件观察股骨内上髁存在率,画出股骨髁上轴线及后髁线并测量两条轴线之间角度,即股骨后髁角度。结果与结论:入选人群男性股骨后髁角度为(2.73±1.28)°,女性股骨后髁角度为(2.35±1.37)°,不同性别间差异无显著性意义。提示MRI测量股骨后髁角具有较大优越性,人工全膝关节置换过程中髁上轴线变异性较小,可参照后髁角度定位安装股骨假体,避免膝关节置换后并发症发生。

BACKGROUND：The good rotational alignment of femoral prosthesis was very important in total knee arthroplasty. The research has shown that the posterior condylar angle was important to determine the alignment. The posterior condylar angle is the angle between the posterior condylar axis and the femoral epicondylar axis. MRI can clearly show the condylar cartilage, the projections of lateral epicondyle and the medial epicondyle depression, thus ensuring accuracy of measurement data. OBJECTIVE：To measure the posterior condylar angle of knee joint in the northern part of Baoding City in China, and to provide image evidence for identifying the rotational alignment of femoral prosthesis during total knee arthroplasty. METHODS：The knee was extended on a neutral position when MRI machine was applied to scan knee joint. The scanning plane was perpendicular to the mechanical axis of the knee. The best T1 axial plane of the knee was chosen, and two observers analyzed images independently. Existence rate of femoral medial epicondyle was observed using Bravo viewer 6.0 imaging software. The posterior condylar angle between posterior condylar axis and the femoral condyle axis was measured. RESULTS AND CONCLUSION：The posterior condylar angle was （2.73±1.28）° in males and （2.35±1.37）° in females on average, which did not show significant difference. The results showed that the MRI had great superiority in measuring the posterior condylar angle. The variability of the epicondylar axis was smal in total＆amp;nbsp;knee arthroplasty. Posterior condylar angle can be referenced to position femoral prosthesis and to avoid the complications after knee replacement.