Validation of a statistical shape model-based 2D/3D reconstruction method for determination of cup orientation after THA

Purpose: The aim of this study was to validate the accuracy and reproducibility of a statistical shape model-based 2D/3D reconstruction method for determining cup orientation after total hip arthroplasty. With a statistical shape model, this method allows reconstructing a patient-specific 3D-model of the pelvis from a standard AP X-ray radiograph. Cup orientation (inclination and anteversion) is then calculated with respect to the anterior pelvic plane that is derived from the reconstructed model. Materials and methods: The validation study was conducted retrospectively on datasets of 29 patients (31 hips). Among them, there were 15 men (15 hips) and 14 women (16 hips). The average age of the patients was 69.4±8.5(49−82) years. Each dataset has one postoperative X-ray radiograph and one postoperative CT scan. The postoperative CT scan for each patient was used to establish the ground truth for the cup orientation. The cup anteversion and inclination that were calculated from the 2D/3D reconstruction method were compared to the associated ground truth. To validate reproducibility and reliability, two observers performed measurements for each dataset twice in order to measure the reproducibility and the reliability of the 2D/3D reconstruction method. Results: Our validation study demonstrated a mean accuracy of 0.4 ± 1.8°(−2.6° to 3.3°) for inclination and a mean accuracy of 0.6±1.5°(−2.0° to 3.9°) for anteversion. Through the Bland-Altman analysis, no systematic errors in accuracy were detected. The method showed very good consistency for both parameters. Conclusions: Our validation results demonstrate that the statistical shape model-based 2D/3D reconstruction-based method is an accurate, consistent, and reproducible technique to measure cup orientation from postoperative X-ray radiographs. The best results were achieved with radiographs including the bilateral anterior superior iliac spines and the cranial part of non-fractured pelvise

Citizen science’s transformative impact on science, citizen empowerment and socio-political processes

Citizen science (CS) can foster transformative impact for science, citizen empowerment and socio-political processes. To unleash this impact, a clearer understanding of its current status and challenges for its development is needed. Using quantitative indicators developed in a collaborative stakeholder process, our study provides a comprehensive overview of the current status of CS in Germany, Austria and Switzerland. Our online survey with 340 responses focused on CS impact through (1) scientific practices, (2) participant learning and empowerment, and (3) socio-political processes. With regard to scientific impact, we found that data quality control is an established component of CS practice, while publication of CS data and results has not yet been achieved by all project coordinators (55%). Key benefits for citizen scientists were the experience of collective impact (“making a difference together with others”) as well as gaining new knowledge. For the citizen scientists’ learning outcomes, different forms of social learning, such as systematic feedback or personal mentoring, were essential. While the majority of respondents attributed an important value to CS for decision-making, only few were confident that CS data were indeed utilized as evidence by decision-makers. Based on these results, we recommend (1) that project coordinators and researchers strengthen scientific impact by fostering data management and publications, (2) that project coordinators and citizen scientists enhance participant impact by promoting social learning opportunities and (3) that project initiators and CS networks foster socio-political impact through early engagement with decision-makers and alignment with ongoing policy processes. In this way, CS can evolve its transformative impact