Tag: fluoroscopy

Influence of the quality of intraoperative fluoroscopic images on the spatial positioning accuracy of a CAOS system

Influence of the quality of intraoperative fluoroscopic images on the spatial positioning accuracy of a CAOS system, by Wang et al. MRCAS (2018) e1898.

Abstract:

Spatial positioning accuracy is a key issue in a computer-assisted orthopaedic surgery (CAOS) system. Since intraoperative fluoroscopic images are one of the most important input data to the CAOS system, the quality of these images should have a significant influence on the accuracy of the CAOS system. But the regularities and mechanism of the influence of the quality of intraoperative images on the accuracy of a CAOS system have yet to be studied.Two typical spatial positioning methods – a C-arm calibration-based method and a bi-planar positioning method – are used to study the influence of different image quality parameters, such as resolution, distortion, contrast and signal-to-noise ratio, on positioning accuracy. The error propagation rules of image error in different spatial positioning methods are analyzed by the Monte Carlo method.Correlation analysis showed that resolution and distortion had a significant influence on spatial positioning accuracy. In addition the C-arm calibration-based method was more sensitive to image distortion, while the bi-planar positioning method was more susceptible to image resolution. The image contrast and signal-to-noise ratio have no significant influence on the spatial positioning accuracy. The result of Monte Carlo analysis proved that generally the bi-planar positioning method was more sensitive to image quality than the C-arm calibration-based method.The quality of intraoperative fluoroscopic images is a key issue in the spatial positioning accuracy of a CAOS system. Although the 2 typical positioning methods have very similar mathematical principles, they showed different sensitivities to different image quality parameters. The result of this research may help to create a realistic standard for intraoperative fluoroscopic images for CAOS systems.

Accuracy analysis of CAS Stryker ADAPT® system for femoral trochanteric fracture using a fluoroscopic navigation system

Open access Accuracy analysis of computer-assisted surgery for femoral trochanteric fracture using a fluoroscopic navigation system: Stryker ADAPT® system, by Takai et al. Injury (2018).

Abstract:

Purpose
ADAPT is a fluoroscopic computer-assisted surgery system which intraoperatively shows the distance from the tip of the screw to the surface of the femoral head, tip-to-head-surface distance (TSD), and the tip-apex distance (TAD) advocated by Baumgaertner et al. The study evaluated the accuracy of ADAPT.

Patients and Methods
A total of 55 patients operated with ADAPT between August 2016 and March 2017 were included as subjects. TSD and TAD were measured postoperatively using computed tomography (CT) and X-rays. The intraclass correlation coefficient (ICC) was checked in advance. The error was defined as the difference between postoperative and intraoperative measurement values of ADAPT. Summary statistics, root mean square errors (RMSEs), and correlations were evaluated.

Results
ICC was 0.94 [95% CI: 0.90–0.96] in TSD and 0.99 [95% CI: 0.98–0.99] in TAD. The error was −0.35 mm (−1.83 mm to 1.12 mm) in TSD and +0.63 mm (−5.65 mm to 4.59 mm) in TAD. RMSE was 0.63 mm in TSD and 1.53 mm in TAD. Pearson’s correlation coefficient was 0.79 [95% CI: 0.66–0.87] in TSD and 0.83 [95% CI: 0.72–0.89] in TAD. There were no adverse events with ADAPT use.

Conclusion
ADAPT is highly accurate and useful in guiding surgeons in properly positioning the screws.