Understanding the morphology of the acetabulum is necessary for preoperative evaluation in hip surgery. The purpose of this study was to (1) establish a novel method for measuring three-dimensional (3D) acetabular orientation, (2) quantify the reliability of this method, and (3) describe relevant characteristics of three-dimensional (3D) acetabular orientation among normal Asian subjects. Computed tomography (CT) scans of the pelvis that had been performed for suspected non-musculoskeletal conditions were obtained from 200 subjects (60 males, 140 females). A novel method was developed to measure 3D acetabular orientation with a semi-automatically determined pelvic coordinate system based on the anterior pelvic plane (APP). To quantify the robustness of our method, we analyzed the results obtained from 20 patients at different times and with different raters and pelvic poses in the same CT volume. To determine morphological differences of the acetabulum by age and sex, we analyzed the parameters of 200 CT volumes. Each intraclass correlation coefficient (ICC) values for intra- and inter-observer reliability were over 0.975 and 0.945, demonstrating high reliability. Furthermore, agreement between the angles determined from the original volume and the rotated volume was nearly perfect (ICCs > 0.956). Multiple linear regression analysis with age and sex as covariates indicated that acetabular inclination was not significantly associated with age (p = 0.687) or sex (p = 0.09). There was also no evidence that acetabular anteversion was associated with age (p = 0.383) or sex (p = 0.53). Our method showed excellent reliability for determining acetabular orientation, as it is robust, fast, and easily applicable to larger populations. In addition, the results of the analysis of acetabular orientation by age and sex can be used as a reference in various diagnostic procedures in orthopedics.

了解髋臼的形态对于髋关节手术的术前评估是必要的。这项研究的目的是（1）建立一种测量三维（3D）髋臼定向的新方法，（2）量化该方法的可靠性，（3）描述三维（3D）髋臼的相关特征普通亚洲人的方向。从200名受试者（60名男性，140名女性）获得了针对怀疑的非肌肉骨骼疾病进行的骨盆的计算机断层扫描（CT）扫描。开发了一种新颖的方法，可使用基于前骨盆平面（APP）的半自动确定的骨盆坐标系来测量3D髋臼方向。为了量化我们方法的健壮性，我们分析了在相同的CT容量下，在不同时间使用不同的评分者和骨盆姿势从20例患者获得的结果。为了确定按年龄和性别划分的髋臼形态差异，我们分析了200个CT量的参数。观察者内和观察者间可靠性的每个类内相关系数（ICC）值都超过0.975和0.945，这表明了高可靠性。此外，由原始体积和旋转体积确定的角度之间的一致性几乎是完美的（ICC> 0.956）。以年龄和性别为协变量的多元线性回归分析表明，髋臼倾角与年龄没有显着相关性（我们分析了200个CT体积的参数。观察者内和观察者间可靠性的每个类内相关系数（ICC）值都超过0.975和0.945，这表明了高可靠性。此外，由原始体积和旋转体积确定的角度之间的一致性几乎是完美的（ICC> 0.956）。以年龄和性别为协变量的多元线性回归分析表明，髋臼倾角与年龄没有显着相关性（我们分析了200个CT体积的参数。观察者内和观察者间可靠性的每个类内相关系数（ICC）值都超过0.975和0.945，这表明了高可靠性。此外，由原始体积和旋转体积确定的角度之间的一致性几乎是完美的（ICC> 0.956）。以年龄和性别为协变量的多元线性回归分析表明，髋臼倾角与年龄没有显着相关性（p  = 0.687）或性别（p  = 0.09）。也没有证据表明髋臼前倾与年龄（p  = 0.383）或性别（p  = 0.53）有关。我们的方法显示出确定髋臼方向的出色可靠性，因为它坚固，快速且易于应用于更大的人群。此外，按年龄和性别划分的髋臼定位分析结果可作为骨科各种诊断程序的参考。