The Use of Two-Dimensional Landmark-Based Geometric Morphometrics to Assess Spinal and Vertebral Malformations in Individuals with Spinal Cord Injuries: A Pilot Study

Abstract

The purpose of this study was to use geometric morphometrics (GMM), a technique suitable for the study of complex anatomical objects, to investigate spinal cord injury (SCI). Eight individuals with SCIs who underwent radiologic evaluation of their lumbar column in a lateral seated position prior to recruitment were included in the study. Each individual was assessed with rasterstereography using the Formetric 4D, and the results were compared with an X-ray of the column analysed through two-dimensional landmark-based GMM. A principal component analysis (PCA) was performed to describe shape variation. Subsequently, the correlation between the Formetric 4D indexes and the shape of the first principal component axis (PC1) was measured with Spearman’s rank correlation coefficient. Thin-plate spline deformation grids were used to describe shape changes in the morphospace depicted by the PCA and to describe shape changes predicted by linear regression. Through the analysis of human X-ray plates, we highlighted the ability of GMM to describe the shape of the column and to evaluate spinal and vertebral malformations. This pilot study is the first step for using a GMM approach to investigate human spinal cord abnormalities. These results provide clinicians and researchers a new method to evaluate bone structures that could provide important information about the development and progression of various deformities in the future.