Department of Orthopedic Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
Acta Orthop. 2012 Feb;83(1):53-8. doi: 10.3109/17453674.2011.641106. Epub 2011 Nov 23.
Identification of the center of the femoral head in the coronal plane is essential during total knee arthroplasty. We evaluated a new method for localization of the center of the hip, thereby detecting the neutral mechanical axis using inter-femoral head center distances (X) measured from a radiograph. Our proposed method was compared with 3 commonly used methods using landmarks that are estimated to be 2 finger-breaths medial to the anterosuperior iliac spine (method A), 2.5 cm perpendicular to the mid-inguinal point (method I), and 1.5 cm lateral to the femoral artery (method F).
114 patients undergoing total knee arthroplasty were prospectively enrolled in the study. Four landmarks were marked and conventional anterior-posterior pelvic radiographs were taken. On the radiograph, the distance between the estimated FHC and the neutral mechanical axis was measured.
The median value (mm) of the measured distance was 9 in A, 7 in I, 8.5 in F, and 5 in X. When an error of more than 3° from neutral alignment was defined as an outlier, 15% of measurements in A, 6% of measurements in I, 14% in F, and 2% in X would fall in the outlier zone.
The method detecting the neutral mechanical axis using inter-femoral head center distances (X) showed the least variability and the lowest percentage of outliers.
在全膝关节置换术中，冠状面股骨头中心的定位至关重要。我们评估了一种新的髋关节中心定位方法，通过测量从髋关节头中心距离（X）来检测中立机械轴。我们的方法与使用前上髂棘内侧估计为 2 指宽（方法 A）、垂直于中腹股沟点 2.5cm（方法 I）和股动脉外侧 1.5cm（方法 F）的 3 个常用方法进行了比较。
前瞻性纳入 114 例全膝关节置换术患者。标记了 4 个标志点，并拍摄了常规前后骨盆 X 线片。在 X 线片上，测量了估计的 FHC 与中立机械轴之间的距离。
A 组测量距离的中位数（mm）为 9，I 组为 7，F 组为 8.5，X 组为 5。当定义偏离中立对齐超过 3°为异常时，A 组有 15%的测量值、I 组有 6%的测量值、F 组有 14%的测量值和 X 组有 2%的测量值落在异常区域。
使用髋关节头中心距离（X）检测中立机械轴的方法显示出最小的变异性和最低的异常百分比。
