Malunion after a distal radius fracture is very common and if symptomatic, is treated with a so-called corrective osteotomy. In a traditional distal radius osteotomy, the radius is cut at the fracture site and a wedge is inserted in the osteotomy gap to correct the distal radius pose. The standard procedure uses two orthogonal radiographs to estimate the two inclination angles and the dimensions of the wedge to be inserted into the osteotomy gap. However, optimal correction in 3-Dspace requires restoring three angles and three displacements. This paper introduces a new technique that uses preoperative planning based on 3-D images. Intraoperative 3-D imaging is also used after inserting pins with marker tools in the proximal and distal part of the radius and before the osteotomy. Positioning tools are developed to correct the distal radius pose in six degrees of freedom by navigating the pins. The method is accurate ( d 1.2 mm, ϕ 0.9°, m TRE = 1.7 mm), highly reproducible (SE (d) < 1.0 mm, SE (ϕ) ≤ 1.4°, SE (m) (TRE) = 0.7 mm), and allows intraoperative evaluation of the end result. Small incisions for pin placement and for the osteotomy render the method minimally invasive.

Image fusion using VesselNavigator enhances the functionality of conventional fluoroscopy in standard endovascular aneurysm repair. It reduces radiation exposure to patients and providers. It also limits the amount of contrast agent and shortens the overall procedure length. The benefit of this technology is demonstrated on this typically straightforward procedure but may be even more useful for complex procedures.

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Background and purpose Developments in flat-panel angiographic c-arm systems have enabled visualization of both the neurovascular stents and host arteries in great detail, providing complementary spatial information in addition to conventional DSA. However, the visibility of these structures may be impeded by artifacts generated by adjacent radio-attenuating objects. We report on the use of a metal artifact reduction (MAR) algorithm for high resolution contrast-enhanced CBCT (VasoCT) for follow-up imaging of stent-assisted coil embolization. Materials and methods VasoCT data was acquired in 25 patients that underwent stent-assisted coiling. Reconstructions were generated with and without MAR and were reviewed by three experienced neuroradiologists using a 3-point scale. Results With MAR, the observers agreed that the visibility had improved by at least one point on the scoring scale in more than 40% of the cases (κ = 0.6) and that the streak artifact was not obscuring surrounding structures in 64% of all cases (κ = 0.6). MAR improved the image quality which allowed for visibility sufficient for evaluation in 65% of the cases, and was preferred over no MAR in 92% (κ = 0.9). Significantly higher scores were given with MAR (p < 0.0001). Conclusion Although MAR is not capable of fully removing artifacts caused by implants with high x-ray absorption, we have shown that the image quality of VasoCT data is improved drastically. The impact of the artifacts on the visibility varied between cases, and yet the overall visibility of the contrast-enhanced CBCT with MAR improved in the majority of the cases.