Department of Orthopedic Surgery, Ehime Seikyo Hospital, 1091-1, Kishi-Cho, Matsuyama, Ehime, 790-0923, Japan.
Knee Surg Sports Traumatol Arthrosc. 2011 Dec;19(12):2009-15. doi: 10.1007/s00167-011-1401-8. Epub 2011 Feb 3.
A new radiographic method using the anterior and posterior femoral condyles as a landmark to determine the rotational alignment of the femoral component in TKA had been developed.
The new radiograph presents an axial view of the distal femur. The patients were asked to lie in the supine position and flex the knee approximately 120° to 130°. Radiographs were applied at an inclination angle of 20° to 30°. The condylar twist angle (CTA), the external rotational angle between the posterior condylar (PC) line and the clinical transepicondylar axis (TEA), and the trochlear line angle (TLA), and the internal rotational angle between the anterior trochlear line and the clinical TEA were measured. Images were taken of 129 knees in 87 patients with osteoarthritis of the knee. The measurement values obtained using our method with those obtained using 3D reconstructed images from a 3-dimensional helical CT system (n = 35) were compared.
The average CTA was 5.7° ± 2.8° and the average TLA was -5.6° ± 3.2°. The CTA was negatively correlated with the tibiofemoral angle (TFA). The average TLA was positively correlated with the TFA. The average difference between the TLA values obtained with this view and those obtained using the 3D-CT was 0.5° ± 1.6°. The relationship between the radiograph and 3D-CT in TLA was higher than that in CTA.
This radiographic technique allows easy and simultaneous measurement of the CTA and TLA and may provide an alternative method for assessing the TEA of the femur during preoperative planning for TKA.
我们开发了一种新的影像学方法，使用股骨髁的前、后作为标志来确定 TKA 中股骨假体的旋转对线。
新的 X 线片呈现出远端股骨的轴位视图。要求患者仰卧位，膝关节屈曲约 120°至 130°。X 线片以 20°至 30°的倾斜角拍摄。测量髁间扭曲角（CTA）、后髁（PC）线与临床髁间轴（TEA）之间的外旋角和滑车线角（TLA）以及前滑车线与临床 TEA 之间的内旋角。对 87 例膝关节骨关节炎患者的 129 个膝关节进行了图像拍摄。比较了我们的方法与三维螺旋 CT 系统 3D 重建图像（n = 35）获得的测量值。
平均 CTA 为 5.7°±2.8°，平均 TLA 为-5.6°±3.2°。CTA 与胫股角（TFA）呈负相关。平均 TLA 与 TFA 呈正相关。该视图与 3D-CT 获得的 TLA 值的平均差值为 0.5°±1.6°。X 线片与 3D-CT 在 TLA 上的相关性高于 CTA。
这种影像学技术可以方便地同时测量 CTA 和 TLA，可能为 TKA 术前规划中股骨 TEA 的评估提供替代方法。
