A novel portable spinal surface scanner for monitoring adolescent idiopathic scoliosis

Abstract

Adolescent idiopathic scoliosis (AIS) remains a major challenge in clinical practice. Routine clinic-based assessments are conducted every 6-12 months for AIS patients until their skeletal maturity to ensure timely interventions for arresting the risk of curve progression and associated adverse outcomes. Non-radiographic tools have played a crucial part in reducing the risk of cancer formation, improving the clinical efficiency, and relieving the burdens on affected families. Surface topography (ST) is one of the promising options, which, however, has received limited uses due to the technique complexity and the failure to refine the role in AIS management. The current work aims to assess the relationship between curve progression and surface topographic change, and the potential of a novel spinal surface scanner (i.e. SpineScan3D) for monitoring AIS patients.

A scoping review was conducted on the clinical effectiveness of ST techniques for monitoring AIS. To assess the reliability and validity of SpineScan3D, AIS patients were recruited from a scoliosis clinic from 2020 to 2023. Biplanar spinal radiographs and surface assessments using SpineScan3D and Scoliometer were conducted with coronal Cobb angle (CCA), thoracic kyphosis, lumbar lordosis, axial and sagittal tilt angles, and trunk rotation recorded for reliability and validity analyses. To investigate the monitoring effectiveness of SpineScan3D, AIS patients were prospectively recruited and followed with radiographic and surface assessments performed at each visit. The correlations between curve progression and surface topographic changes were analysed, followed by the analysis of the monitoring effectiveness and the impact factors.

11 studies were analysed in the scoping review, which applied optical-based techniques and showed varying monitoring effectiveness results. 272 AIS patients were included in the cross-sectional study, where a strong-to-very-strong reliability was demonstrated for axial and sagittal tilt measures. Strong-to-very-strong relationships were found between SpineScan3D and Scoliometer measures, while both showed moderate correlations with CCA and the ability to predict moderate curves. Significant correlations were detected between sagittal radiographic and surface measures, with BMI found as an impact factor. 364 patients were recruited and followed for a mean of 21 months. Significant correlations were detected between curve progression and surface topographic changes. Overall monitoring accuracy, sensitivity, and specificity were 72%, 58%, 76%, with 60% follow-ups potentially avoided and 9% cases missed. Subjects with double major curves or triple curves, and with a small initial trunk deformity shower improved performance, reaching an overall accuracy, sensitivity, specificity of 75%, 79%, 74%, and potentially reducing 57% follow-ups with only 5% cases missed.

With all these findings, this is the first to prove that SpineScan3D, as a tactile-based ST technique, is reliable and accurate in assessing AIS, and more excitingly, it is clinically effective in monitoring curve progression. Therefore, it has a great potential to be used as a portable and user-friendly monitoring tool for AIS patients. The current work has provided a valuable insight into the role of ST techniques as an aid in the surveillance of AIS children, which can significantly help relieve the burdens on healthcare providers and improve the clinical and patient-related outcomes for the affected population.