Department of Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland; Department of Orthopaedics, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
Department of Research in Orthopedic Computer Science, Balgrist University Hospital, University of Zurich, Zurich, Switzerland.
J Hand Surg Am. 2020 Nov;45(11):1083.e1-1083.e11. doi: 10.1016/j.jhsa.2020.04.021. Epub 2020 Jun 16.
To develop reproducible 3-dimensional measurements for quantification of the distal radioulnar joint (DRUJ) morphology. We hypothesized that automated 3-dimensional measurement of the ulnar variance (UV) and the sigmoid notch (SN) angle would be comparable to those of the reference standard while overcoming some drawbacks of conventional 2-dimensional measurements.
Radiological data of healthy forearm bones (radiographs and computed tomography) of 53 adult subjects were included in the study. Automated measurements were developed for assessment of the SN morphology based on 3-dimensional landmarks, incorporating subject-specific estimation of cartilage surface orientation. A common anatomical reference was defined among the different imaging modalities and a comparison of the SN angle and UV measurements was performed in radiographs, computed tomography scans, and 3-dimensional models. Finally, the 3-dimensional UV measurements were evaluated in an experimental setup using 3-dimensional printed bone models.
The automated 3-dimensional measurements of SN subtypes showed a notably larger notch radius (18.9 mm) for negative SN angles compared with positive SN angles in subjects (16.9 mm). Similar UV measurements were obtained in healthy DRUJ morphologies, with a high correlation between radiographs and 3-dimensional measurements for the SN angle (0.77) and UV (0.85). In the experimental setup with pathological radial inclinations, UV was on average 1.13 mm larger in the radiographs compared with the 3-dimensional measurements, and 1.30 mm larger in the cases with pathological palmar tilts. Furthermore, UV radiograph measurements on the modified palmar tilt deviated from the 3-dimensional measurements.
The developed 3-dimensional automated measurements were able to quantify morphological differences among sigmoid notch subtypes and were comparable to those of the reference standard.
The developed methods do not depend on the forearm position or orientation of the distal radius and can be used for 3-dimensional quantification of DRUJ pathologies in 3-dimensional surgical planning.
开发可重现的三维测量方法，以量化远端桡尺关节（DRUJ）的形态。我们假设，在克服二维测量的一些缺点的同时，对尺侧倾斜（UV）和月骨切迹（SN）角的自动三维测量将与参考标准相媲美。
本研究纳入了 53 名成年受试者的健康前臂骨骼（X 线片和 CT）的影像学资料。基于三维标志点开发了用于评估 SN 形态的自动测量方法，该方法纳入了对软骨表面方向的个体特异性估计。在不同的成像模式之间定义了一个共同的解剖参考，并在 X 线片、CT 扫描和三维模型中比较了 SN 角和 UV 测量值。最后，在使用三维打印骨模型的实验设置中评估了三维 UV 测量值。
与阳性 SN 角相比，在受试者中，SN 亚型的自动三维测量显示出明显更大的负 SN 角切迹半径（18.9mm）（16.9mm）。在健康的 DRUJ 形态中，获得了相似的 UV 测量值，SN 角（0.77）和 UV（0.85）的 X 线片和三维测量值高度相关。在具有病理性桡骨倾斜的实验设置中，与三维测量相比，X 线片上的 UV 平均大 1.13mm，而在具有病理性掌倾的情况下，UV 大 1.30mm。此外，改良掌倾 X 线片上的 UV 测量值与三维测量值存在偏差。
开发的三维自动测量方法能够量化 SN 切迹亚型之间的形态差异，并与参考标准相媲美。
所开发的方法不依赖于前臂的位置或远端桡骨的方向，可用于三维手术计划中 DRUJ 病变的三维定量分析。
