Is there any use? Validity of 4D rasterstereography compared to EOS 3D X-ray imaging in patients with degenerative disk disease

Abstract

Introduction: Previous studies of 4D rasterstereography show a high intra- and interday reliability. However, only few studies validate rasterstereography to conventional X-ray imaging. We utilized EOS X-ray imaging system (EOS Imaging, Paris, France) for accurate 3D spinal modeling and compared the results to parameters obtained by 4D rasterstereography. The aim of the present study was to validate 4D rasterstereography in patients with degenerative disk disease (DDD). Materials and method: Thirty-four individuals with DDD (female = 22 and male = 12) were included. EOS X-ray images were analyzed to determine spinal [lumbar lordosis (LL) and thoracic kyphosis (TK)] and pelvic parameters [pelvic obliquity (PO) and pelvic axial rotation (PR)]. Patients received 4D rasterstereographic measurements on the same day as EOS imaging. Parameters obtained by rasterstereography were compared to those obtained by EOS X-ray imaging. We used Bland and Altman’s test as well as Pearson test to validate rasterstereography. Additionally, we calculated interrater reliability of EOS X-ray analysis using the intraclass correlation coefficient (ICC). Results: Our data showed only weak correlation between 4D rasterstereography and EOS X-ray imaging for spinal parameters (LL and TK). Pelvic parameters (PO and PR) showed no correlation. Interrater correlation reliability for EOS analysis was excellent (ICC > 0.8). Conclusion: Our data suggest that rasterstereographic systems are no reliable substitute for X-ray-based imaging systems in patients with degenerative disk disease. EOS imaging was shown to provide reliable and accurate spinal modeling. Based on our results, rasterstereographic imaging should be used with caution for evaluating spinal and pelvic parameters in patients with DDD. Graphic abstract: These slides can be retrieved under Electronic Supplementary Material.[Figure not available: see fulltext.].