Boese Christoph K, Bredow Jan, Dargel Jens, Eysel Peer, Geiges Hansjörg, Lechler Philipp
Department of Orthopaedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany.
Mathematical Institute, University of Cologne, Cologne, Germany.
J Arthroplasty. 2016 Apr;31(4):883-7. doi: 10.1016/j.arth.2015.10.009. Epub 2015 Oct 26.
We report a mathematical method to assess the vertical and horizontal positions of spherical radiopaque objects of known size in conventional radiographs.
The reliability and validity of the method were tested in an experimental setting and applied to 100 anteroposterior pelvic radiographs with external calibration markers and unilateral total hip arthroplasty (THA).
We found excellent reliabilities; intraclass correlation coefficients for interobserver and intraobserver reliabilities were 0.999-1.000 (P = .000). The mean normal height of THA was 198 mm (range: 142-243 mm, standard deviation: 18 mm) above the detector. Vertical and horizontal external marker positions differed significantly from the true hip center (THA; P < .001 and P = .017).
This method could enhance patient safety by enabling automated detection of malpositioned calibration markers by templating software.
我们报告一种数学方法，用于在传统X线片中评估已知大小的球形不透射线物体的垂直和水平位置。
该方法的可靠性和有效性在实验环境中进行了测试，并应用于100张带有外部校准标记和单侧全髋关节置换术（THA）的骨盆前后位X线片。
我们发现可靠性极佳；观察者间和观察者内可靠性的组内相关系数为0.999 - 1.000（P = .000）。THA在探测器上方的平均正常高度为198 mm（范围：142 - 243 mm，标准差：18 mm）。垂直和水平外部标记位置与真髋关节中心（THA）有显著差异（P < .001和P = .017）。
该方法可通过模板软件自动检测位置不当校准标记，从而提高患者安全性。
