Department of Orthopaedics and Traumatology, Yeditepe University Hospital, Istanbul, Turkey.
Private Orthopaedic Clinic, Istanbul, Turkey.
Clin Orthop Relat Res. 2024 Dec 1;482(12):2136-2144. doi: 10.1097/CORR.0000000000003159. Epub 2024 Jul 12.
The acetabular version is crucial for hip function, and its accurate assessment is necessary for treating patients with hip disorders. Current studies reveal discrepancies in the precision of quantitative radiographic measurements versus CT measurements, but there is a lack of focused analysis on anteverted versus retroverted hips. This study aims to fill this gap by directly comparing the reliability of these two methods in assessing varied hip configurations.
QUESTIONS/PURPOSES: (1) How reliable are quantitative radiographic and CT methods in measuring the acetabular version angle? (2) Is there any difference in the reliability of acetabular version angle measurements using radiography compared with CT in anteverted and retroverted hips? (3) What is the extent of variation in acetabular version measurements when quantitative radiographic and CT methods are compared in anteverted and retroverted hips?
We searched our image archives for patients who had received both radiographs and CT scans between January 2020 and June 2022 and found 84 patients who met the criteria. From these patients, we selected those who presented with hip pain of different causes and who had no previous elective and/or hip trauma surgery, no hip dysplasia, and results from adequate radiographic examinations. Accordingly, 73% (61 of 84) of the patients were included in this study, and angle measurements were performed on both hips of these patients (122 hips). Standardized positioning was meticulously verified for all plain radiographs and CT scans utilized in the measurement process. We measured quantitative angles and assessed qualitative signs of retroversion, including crossover, posterior wall, and ischial spine findings. We considered a hip with at least one of these findings a retroverted hip, and the hips without these findings were included in the anteverted hip group. Three clinicians took measurements independently. Measurement reliability and agreement were examined using intraobserver and interobserver intraclass correlation coefficients (ICCs), with statistical analyses including paired and independent t-tests. To investigate the reliability of quantitative radiographic and CT methods, we assessed both intraobserver and interobserver agreements. To explore the reliability disparities in measuring the acetabular version via radiography and CT in anteverted and retroverted hips, we analyzed the agreement between measurements from both modalities in the hip groups. Furthermore, to evaluate the degree of variation in acetabular version measurements when comparing quantitative radiographic and CT methods in anteverted and retroverted hips, we utilized paired and independent t-tests to examine the measurement differences within these hip categories. The difference between radiographic and CT measurements was also evaluated by Bland-Altman analysis.
Quantitative radiographic measurements showed intraobserver and interobserver reliabilities with ICCs of 0.87 (95% CI 0.84 to 0.91) and 0.78 (95% CI 0.75 to 0.82), respectively, and CT measurements demonstrated higher reliabilities with ICCs of 0.92 (95% CI 0.90 to 0.93) and 0.91 (95% CI 0.89 to 0.92), respectively. The reliability of measuring the acetabular version in anteverted hips was moderate, with an ICC of 0.59 (95% CI 0.49 to 0.68). In contrast, retroverted hips showed an ICC of -0.41 (95% CI -1.17 to 0.08), indicating a lack of consistency between quantitative radiographic and CT measurements. Variation in measurement on plain radiographs in anteverted hips was less than that of retroverted hips (mean ± SD absolute difference between anteverted hips and retroverted hips 3° ± 3° versus 6° ± 4°; p = 0.0001), indicating greater variability in the radiographic measurement of retroverted hips. According to Bland-Altman analysis, we observed that the difference between radiographic and CT measurements was well outside the CI, especially in retroverted hips.
Although quantitative radiographic measurement demonstrates acceptable intraobserver and interobserver reliabilities, its precision is lower than that of CT-based measurements. Specifically, quantitative radiographic methods are prone to a larger margin of error in retroverted hips. For more precise assessments of acetabular version, especially in retroverted hips, we recommend using CT measurement instead of the radiographic method.
Level III, diagnostic study.
髋臼的形态对于髋关节的功能至关重要，准确评估髋臼形态对于治疗髋关节疾病的患者非常重要。目前的研究表明，定量放射学测量与 CT 测量的精度存在差异，但对于前倾和后倾髋关节，缺乏针对性的分析。本研究旨在通过直接比较这两种方法在评估不同髋关节形态方面的可靠性来填补这一空白。
问题/目的：（1）定量放射学和 CT 方法测量髋臼角度的可靠性如何？（2）在前倾和后倾髋关节中，与 CT 相比，放射学测量髋臼角度的可靠性是否存在差异？（3）在比较前倾和后倾髋关节时，定量放射学和 CT 方法测量髋臼角度的差异有多大？
我们在 2020 年 1 月至 2022 年 6 月期间在我们的影像档案中搜索了同时接受放射学和 CT 扫描的患者，并找到了符合条件的 84 名患者。从这些患者中，我们选择了那些因不同原因出现髋关节疼痛且没有接受过选择性和/或髋关节创伤手术、没有髋关节发育不良以及放射学检查结果充分的患者。因此，研究纳入了 73%（61/84）的患者，对这些患者的双侧髋关节（122 个髋关节）进行了角度测量。在测量过程中，我们仔细验证了所有平片和 CT 扫描的标准化定位。我们测量了定量角度，并评估了髋臼后倾的定性征象，包括交叉征、后壁和坐骨棘征。我们将至少存在这些征象之一的髋关节视为后倾髋关节，而没有这些征象的髋关节则归入前倾髋关节组。三名临床医生独立进行了测量。我们使用组内和组间的观察者内和观察者间的组内相关系数（ICC）来评估测量的可靠性和一致性，并进行配对和独立 t 检验等统计学分析。为了评估定量放射学和 CT 方法的可靠性，我们评估了观察者内和观察者间的一致性。为了探讨在前倾和后倾髋关节中，通过放射学和 CT 测量髋臼角度的可靠性差异，我们分析了在髋关节组中两种模态之间的测量一致性。此外，为了评估在比较前倾和后倾髋关节时，定量放射学和 CT 方法测量髋臼角度的差异程度，我们使用配对和独立 t 检验在这些髋关节类别中检查了测量差异。还通过 Bland-Altman 分析评估了放射学和 CT 测量之间的差异。
定量放射学测量的观察者内和观察者间可靠性的 ICC 分别为 0.87（95%CI 0.84 至 0.91）和 0.78（95%CI 0.75 至 0.82），CT 测量的可靠性更高，ICC 分别为 0.92（95%CI 0.90 至 0.93）和 0.91（95%CI 0.89 至 0.92）。前倾髋关节测量髋臼角度的可靠性为中度，ICC 为 0.59（95%CI 0.49 至 0.68）。相比之下，后倾髋关节的 ICC 为-0.41（95%CI-1.17 至 0.08），表明定量放射学和 CT 测量之间缺乏一致性。前倾髋关节的平片测量的变化幅度小于后倾髋关节（平均±标准差，前倾髋关节和后倾髋关节之间的绝对差值为 3°±3°与 6°±4°；p=0.0001），表明后倾髋关节的放射学测量变化更大。根据 Bland-Altman 分析，我们发现放射学和 CT 测量之间的差异超出了 CI，尤其是在后倾髋关节中。
尽管定量放射学测量具有可接受的观察者内和观察者间可靠性，但与 CT 测量相比，其精度较低。具体来说，在测量后倾髋关节时，定量放射学方法更容易出现较大的误差。对于髋臼角度的更精确评估，特别是在后倾髋关节中，我们建议使用 CT 测量而不是放射学方法。
III 级，诊断研究。
