Departments of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Departments of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
Orthop Traumatol Surg Res. 2019 Feb;105(1):17-21. doi: 10.1016/j.otsr.2018.11.008. Epub 2018 Dec 26.
The Dorr classification is widely used to evaluate femoral bone quality, but it has no clear quantitative criteria. This study aimed to evaluate the reproducibility of the Dorr classification and examine its quantitative indices on plain radiographs, which are suitable for objective classification.
Reproducibility of the Dorr classification is influenced by the clinical experience of the examiners, and radiographic indices are required for this classification.
One hundred and one patients were examined using their preoperative plain antero-posterior and lateral radiographs. To evaluate the reproducibility of the Dorr classification, the Dorr type of each patient was judged twice each by three expert hip surgeons and three junior hip surgeons. Indices measured using the plain radiographs were canal-to-calcar ratio, cortical index (CI), and canal flare index. A receiver operating characteristic curve was used to evaluate which measured parameters were suitable as indices for the Dorr classification which was determined by the consultation among three expert hip surgeons.
Regarding intra-examiner reproducibility, kappa coefficients for the three junior hip surgeons were 0.36, 0.62, and 0.65, whereas those for the three expert hip surgeons were 0.70, 0.86, and 0.87. Regarding inter-examiner reproducibility, the kappa coefficient for the junior hip surgeons was 0.32, whereas that for the expert hip surgeons was 0.52. The CI on the lateral radiograph had the largest area under the curve (AUC) between types A and B, whereas the CI on the anteroposterior radiograph had the largest AUC between types B and C. The respective cutoff points of the CI on the anteroposterior radiograph were 0.58 between types A and B and 0.49 between types B and C. The respective cutoff points of CI on the lateral radiograph were 0.45 between types A and B and 0.28 between types B and C.
The intra-examiner reproducibility of the Dorr classification ranged from "fair" to "almost perfect", whereas the inter-examiner reproducibility ranged from "fair" to "moderate". Both were influenced by the level of clinical experience of the examiners. The most suitable index for classification using plain radiographs of the hip is the CI on anteroposterior and lateral radiographs.
IV, retrospective study.
多尔分类被广泛用于评估股骨骨质量，但它没有明确的定量标准。本研究旨在评估多尔分类的可重复性，并研究其在适合客观分类的普通 X 线片上的定量指标。
多尔分类的可重复性受检查者临床经验的影响，并且该分类需要放射学指标。
对 101 例患者进行术前正位前后位和侧位 X 线检查。为了评估多尔分类的可重复性，由 3 名髋部专家和 3 名初级髋部外科医生对每位患者的多尔类型进行了两次判断。使用普通 X 线片测量的指标有：管腔-骺板比、皮质指数（CI）和管腔张开指数。使用受试者工作特征曲线评估哪些测量参数适合由 3 名髋部专家共同确定的多尔分类作为指标。
在内部观察者的可重复性方面，3 名初级髋部外科医生的kappa 系数分别为 0.36、0.62 和 0.65，而 3 名髋部专家的kappa 系数分别为 0.70、0.86 和 0.87。在外部观察者的可重复性方面，初级髋部外科医生的kappa 系数为 0.32，而髋部专家的 kappa 系数为 0.52。在 X 线片上，CI 的曲线下面积（AUC）在 A 型和 B 型之间最大，而在前后位 X 线片上，B 型和 C 型之间的 AUC 最大。前后位 X 线片上 CI 的截断点分别为 A 型和 B 型之间的 0.58 和 B 型和 C 型之间的 0.49。侧位 X 线片上 CI 的截断点分别为 A 型和 B 型之间的 0.45 和 B 型和 C 型之间的 0.28。
多尔分类的内部观察者可重复性范围为“一般”到“几乎完美”，而外部观察者可重复性范围为“一般”到“中等”。两者都受检查者临床经验水平的影响。最适合用于髋关节普通 X 线片分类的指标是前后位和侧位 X 线片上的 CI。
IV，回顾性研究。
