Rastersterographic measurement of scoliotic deformity: reducing X-ray exposure in adolescent idiopathic scoliosis patient

INTRODUCTION: Radiographic investigation, frequently used in the diagnosis of scoliosis, has several limitations: invasiveness, two-dimensionality, and static nature. Over the years, new technologies for postural analysis such as the rasterstereographic system have been increasingly used. The aim of the following literature review was to compare radiography, the instrumental gold standard for the diagnosis and follow-up of scoliosis and video-raster stereography, a three-dimensional evaluation system of the spine through analysis of the surface of the back. EVIDENCE ACQUISITION: The review of the literature on the subject was carried out in the PubMed database from January 2, 2020 to May 31, 2020. The research strategy has been developed following the PICO method and the selection process for the studies included in the review has been reported in the PRISMA diagram. EVIDENCE SYNTHESIS: The results indicate that the rasterstereographic parameters as lateral vertebral deviation and vertebral rotation accurately reflect the radiographically measured progression of idiopathic scoliosis, but these parameters are not directly comparable with the Cobb angle, which is measured on the radiography and is the main criterion of diagnosing scoliosis. Although it cannot replace radiography, rasterstereography is a valid and reliable tool, both as interobserver and intraobserver tool. It is completely radiation-free and could help monitor the progression of scoliosis. When compared to the clinical forward bend test and the scoliometer, it is more reliable. CONCLUSIONS: The usefulness of this evaluation method lies in the reproducible quantification of deformity once the initial radiography has been made. It could be used for screening tests and follow-up.