Seo Hajime, Naito Masatoshi, Nakamura Yoshinari, Kinoshita Koichi, Nomura Tomohiro, Minokawa So, Minamikawa Tomohiko, Yamamoto Takuaki
Department of Orthopaedic Surgery, Fukuoka University Faculty of Medicine, Nanakuma, Fukuoka - Japan.
Department of Orthopaedic Surgery, Fukuoka Sanno Hospital, Momochihama, Fukuoka - Japan.
Hip Int. 2017 May 12;27(3):293-298. doi: 10.5301/hipint.5000456. Epub 2017 Jan 31.
Various methods have been described for measuring acetabular component anteversion. However, accurate measurement of anteversion is difficult. We herein propose a new method using cross-table lateral (CL) radiography performed with the contralateral hip flexed to 45° (45° flexed CL radiography). The main purpose of this study was to evaluate the reliability and validity of this new method.
The study group included 93 patients who underwent total hip arthroplasty (THA). All hips were evaluated with computed tomography (CT) and both standard and 45° flexed CL radiographs to measure acetabular component anteversion the week after THA. The intraobserver and interobserver reliability of each measurement was assessed. Plain radiography measurements were compared with reference CT measurements to evaluate their validity.
All measurements had excellent intraobserver and interobserver reliability, and plain radiography measurements correlated well with CT measurements. The mean measurements were 21.9° (3°-39°) with CT, 24.9° (7°-47°; p<0.001) with standard CL radiographs, and 22.5° (7°-43°; p = 0.112) with 45° flexed CL radiographs.
The anteversion values measured with our new method were closer to the CT values used as a reference standard than those with standard CL radiographs. Our new method appears to be reliable and valid for measuring acetabular component anteversion.
已经描述了多种测量髋臼假体前倾角的方法。然而，准确测量前倾角很困难。我们在此提出一种新方法，即对侧髋关节屈曲至45°时进行的交叉台面侧位（CL）X线摄影（45°屈曲CL X线摄影）。本研究的主要目的是评估这种新方法的可靠性和有效性。
研究组包括93例行全髋关节置换术（THA）的患者。在THA术后一周，对所有髋关节进行计算机断层扫描（CT）以及标准和45°屈曲CL X线片检查，以测量髋臼假体前倾角。评估每种测量方法的观察者内和观察者间可靠性。将普通X线摄影测量结果与参考CT测量结果进行比较，以评估其有效性。
所有测量均具有出色的观察者内和观察者间可靠性，并且普通X线摄影测量结果与CT测量结果相关性良好。CT测量的平均值为21.9°（3°-39°），标准CL X线片测量的平均值为24.9°（7°-47°；p<0.001），45°屈曲CL X线片测量的平均值为22.5°（7°-43°；p = 0.112）。
与标准CL X线片相比，我们新方法测量的前倾角值更接近用作参考标准的CT值。我们的新方法似乎对于测量髋臼假体前倾角是可靠且有效的。
