Accuracy assessment of 2D X-ray to 3D CT registration for measuring 3D postoperative implant position
Many recent advancements in surgical technologies, like patient specific surgical guides or surgical robots, are specifically developed for accurately placing an implant in 3D. However, the majority of accuracy studies on these techniques base their conclusions on 2D measurements on postoperative Xray images.
Using 2D/3D registration, it is possible to combine a preoperative CT or MRI scan, a 3D model of the implant and one or more postoperative X-ray images, to determine 3D postoperative implant position without the need of an additional CT or MRI scan.
The objective of this study was to determine the accuracy and inter- and intra-operator variability of this technique for a total knee arthroplasty (TKA). The experiments performed on both phantom and cadaver specimens indicated that an average measurement error smaller than 0.6 mm and 0.5 ° can be obtained.
This study shows that 2D/3D registration of Xray images to 3D models allows for measuring 3D implant position to a sufficient accuracy for evaluating 3D planning based surgical methods for TKA.