Liu Lu, Liu Chang, Rong Yan-Bo, Bai Fan, Chen Shan-Lin
Department of Hand Surgery, Beijing Ji Shui Tan Hospital, Beijing, China.
Ann Plast Surg. 2020 May;84(5S Suppl 3):S196-S201. doi: 10.1097/SAP.0000000000002368.
Congenital proximal radioulnar synostosis (CPRUS) is a relatively rare forearm deformity that is characterized by a fixed pronated forearm of varying severity. The osseous synostosis between the proximal part of the ulna and the radius can be seen on the X-ray images in most cases. Many researchers have attempted to identify methods to measure the disease severity to guide in the treatment of CPRUS. However, to describe the overall deformity, the use of multiple indicators is essential, and some of these measurements require special software or need to be conducted on cadavers.
The aim of the current study was to introduce the radius pronation angle (RPA), a novel radiological evaluation index of CPRUS, and analyze the relationship between the RPA and the severity of the deformity.
Three-dimensional models of 43 CPRUS forearms (19 left forearms and 24 right forearms) of 32 patients (23 males and 9 females; average age was 6 years 8 months; range, from 1.5 to 27 years) treated at Beijing Ji Shui Tan Hospital during 2016 to 2019 were reconstructed using a computer-assisted technique. The special flexed posterior-anterior views of the X-ray image (the f-PA view) of the forearms were obtained, and the forearm rotation angle and the ulnar inner rotation angle were measured on each forearm. The RPA was measured on the f-PA view, and the lengths of the osseous synostosis, ulna, and the radial head were measured on the computed tomography scan images using the multiplanar reconstruction function. The Pearson index was analyzed between the RPA and the other measurements.
The RPAs were correlated with the forearm rotation angle, ulnar inner rotation angle, relative length of the osseous synostosis, and the relative length of the radial head (P < 0.05).
The RPA can be measured quickly and easily on the f-PA view of the X-ray image and can be used as a reliable indicator of the severity of CPRUS.
先天性近端桡尺关节融合（CPRUS）是一种相对罕见的前臂畸形，其特征为前臂不同程度的固定旋前。在大多数情况下，X线图像上可见尺骨近端与桡骨之间的骨性融合。许多研究人员试图确定测量该疾病严重程度的方法，以指导CPRUS的治疗。然而，为了描述整体畸形，使用多个指标至关重要，其中一些测量需要特殊软件或需要在尸体上进行。
本研究的目的是引入桡骨旋前角（RPA），一种CPRUS的新型影像学评估指标，并分析RPA与畸形严重程度之间的关系。
采用计算机辅助技术重建了2016年至2019年在北京积水潭医院接受治疗的32例患者（23例男性和9例女性；平均年龄6岁8个月；范围为1.5至27岁）的43个CPRUS前臂的三维模型（19个左前臂和24个右前臂）。获得前臂X线图像的特殊屈曲前后位视图（f-PA视图），并测量每个前臂的前臂旋转角度和尺骨内旋角度。在f-PA视图上测量RPA，并使用多平面重建功能在计算机断层扫描图像上测量骨性融合、尺骨和桡骨头的长度。分析RPA与其他测量值之间的Pearson指数。
RPA与前臂旋转角度、尺骨内旋角度、骨性融合的相对长度以及桡骨头的相对长度相关（P<0.05）。
RPA可以在X线图像的f-PA视图上快速、轻松地测量，并且可以用作CPRUS严重程度的可靠指标。
