Tag: Accuracy

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.

Computer-assisted surgery prevents complications during peri-acetabular osteotomy

periacetabular-osteotomy-preoperative

Computer-assisted surgery prevents complications during peri-acetabular osteotomy, Hayashi, S., Hashimoto, S., Matsumoto, T. et al. International Orthopaedics (SICOT) (2018).

Abstract:

Purpose
The aim of study is to evaluate the accuracy of a navigation system during curved peri-acetabular osteotomy (CPO).

Methods
Forty-seven patients (53 hips) with hip dysplasia were enrolled and underwent CPO with or without navigation during surgery. Clinical and radiographical evaluations were performed and compared between the navigation group and non-navigation group, post-operatively.

Results
The clinical outcomes were not significantly different between the navigation and non-navigation groups. Furthermore, post-operative reorientation of the acetabular fragment was similar between the navigation and non-navigation groups. However, the discrepancy between the pre-operative planning line and post-operative osteotomy line was significantly improved in the navigation group compared with that in the non-navigation group (p < 0.05). Further, the complication rate was significantly improved in the navigation group (p < 0.001). Conclusion The accuracy of the osteotomy’s position was significantly improved by using the navigation. Therefore, the use of navigation during peri-acetabular osteotomy can avoid complications.

periacetabular-osteotomy-preoperative-planning
The measurement of the distance between the 100-mm radius sphere line that was determined during pre-operative planning and the post-operative iliac bone surface (the error distance) on the a coronal and b axial planes. a The error distance outside the pelvis on the coronal plane (50–45.5 mm= 4.5 mm). b The error of the distance inside the pelvis on the axial plane (57.8–50 mm= 7.8 mm)