Investigating approaches and devices for scoliosis monitoring

Scoliosis is a medical condition characterized by abnormal spinal curvature. It predominantly affects children and adolescents, with a prevalence ranging from 0.5% to 5% in the population. It has a profound impact on trunk anatomy and physical appearance, influencing individuals' overall well-being and physical abilities. Managing scoliosis necessitates vigilant monitoring, especially to prevent disease progression and to assess treatment effectiveness. Monitoring typically occurs at regular intervals, such as biannually. However, traditional methods for evaluating the spine involve the repeated use of X-ray radiographs, resulting in cumulative radiation exposure. The frequency of these X-rays varies depending on the treatment strategy, potentially exposing patients to harmful levels of radiation, raising concerns about the risk of malignancies. Studies indeed have shown an increased risk of premature mortality and cancer development in individuals subjected to cumulative X-ray exposure during scoliosis follow-up. This work aims to explore whether alternative technologies have reached a stage where they could revolutionize scoliosis management. Its primary focus is on techniques for monitoring this condition rather than diagnosing it, as the repetitive use of X-rays for monitoring poses a substantial radiation risk. The first part of this research encompasses a systematic literature review, investigating the current state of non-invasive and non-ionizing methods for scoliosis monitoring. The objective is to perform a meta-analysis, implementing statistical models to assess the precision and reliability of these approaches compared to the X-rays, which are used to calculate the Cobb angle—a crucial metric in quantifying spinal deformity, in order to understand what approach is the most suitable to replace the actual gold standard. Furthermore, the study explores the implementation of a monitoring method based on back surface topography measurements and predictions of spinal alignment. This approach involves sequential back scans of patients over time to evaluate changes in back shape and their correlation with clinical indicators or internal spinal characteristics. Lastly, the participation in a clinical study at the University Hospital Balgrist is presented, where a low-cost optical device was implemented and tested to establish a correlation between the three-dimensional shape of the dorsal surface and corresponding radiographs of scoliotic spines. Among the various techniques examined, ultrasound-based methods have proven to be the most accurate and reliable compared to the gold standard. However, the technique of surface topography has also been extensively analyzed, highlighting how the back reconstructions provided by it can effectively estimate the changing shape of the spine over time. The new parameters derived from this technique represent a novel way of assessing scoliosis and the registration procedure implemented allowed to create an easy monitoring tool for physicians. While these techniques have not yet completely replaced the gold standard, they are certainly suitable for reducing its frequency, reducing radiation exposure and improving patient care.