Piedade Sergio Rocha, Ferreira Daniel Miranda, Hutchinson Mark, Maffulli Nicola, Mischan Martha Maria, Neyret Philippe
Universidade Estadual de Campinas, Faculdade de Ciências Médicas, Campinas, SP, Brazil.
University of Illinois at Chicago, Chicago, IL, USA.
Acta Ortop Bras. 2021 Jul-Aug;29(4):189-192. doi: 10.1590/1413-785220212904240251.
By analyzing our cases of posterior cruciate ligament (PCL) tibial avulsion fracture, we noted that a U-shaped image was present in the anteroposterior plain radiographs view of the affected knee, even in cases where the profile view of the knee had been inconclusive as to tibial PCL avulsion fracture, a "hidden" fracture. Therefore, we aimed to investigate whether there was an anatomical correlation between this radiological U sign and the tibial insertion of the PCL and to ascertain the intra- and inter-rater reliability of this sign in clinical practice.
The data of the widths and heights area of the PCL tibial insertion area, and the U sign area were measured and compared to the largest width of the tibia. Two moreover, the reliability and reproducibility of this imaging were analyzed.
The areas height of the U-sign area and the anatomical insertion area of the posterior cruciate ligament showed no difference, and both were topographically located in the two central quarters of the proximal end of the tibia. The radiographic assessment showed excellent Kappa agreement rates between interobserver and intraobserver, with high reliability and reproducibility.
The U sign is a radiographic feature of PCL tibial avulsion fracture seen on the radiograph AP view, there is a high association between the ratios of the U-sign area height in the X-ray and the anatomical height of the PCL tibial insertion site MRI with the largest width of the proximal tibia. The radiographic U sign showed excellent rates of interobserver and intraobserver agreement with Kappa values higher than 0.8.
通过分析我们收治的后交叉韧带（PCL）胫骨撕脱骨折病例，我们注意到在患侧膝关节前后位平片上会出现一个U形影像，即使在膝关节侧位片对胫骨PCL撕脱骨折（一种“隐匿性”骨折）诊断不明确的情况下也是如此。因此，我们旨在研究这种放射学U征与PCL胫骨附着点之间是否存在解剖学关联，并确定该征象在临床实践中的观察者内和观察者间可靠性。
测量PCL胫骨附着区的宽度、高度面积以及U征区域的数据，并与胫骨最大宽度进行比较。此外，分析这种影像学检查的可靠性和可重复性。
U征区域的高度与后交叉韧带的解剖附着区高度无差异，且两者在地形学上均位于胫骨近端的两个中央象限。影像学评估显示观察者间和观察者内的Kappa一致性率极佳，具有高可靠性和可重复性。
U征是PCL胫骨撕脱骨折在X线前后位片上的一个影像学特征，X线片上U征区域高度与PCL胫骨附着部位MRI的解剖高度与胫骨近端最大宽度之间存在高度相关性。影像学U征显示观察者间和观察者内一致性率极佳，Kappa值高于0.8。
