Eur J Anat, 22 (1): 37-49 (2018)

Body Mass Index and sagittal lumbar balance. A geometric morphometrics approach

José Aso Escario¹, Cristina Sebastián Sebastián², Alberto Aso-Vizan³, José V. Martínez-Quiñones¹, Fabián Consolini Rossi¹, Ricardo Arregui Calvo¹

¹Hospital MAZ, Department of Neurosurgery, Zaragoza, Spain, ²Hospital MAZ, Department of Radiology, Zaragoza, Spain, ³Hospital General de la Defensa, Department of Traumatology and Orthopedic Surgery, Zaragoza, Spain

ABSTRACT Geometric Morphometrics (GM) offers a new and interactive way for shape analysis, rarely used in spine morphology study. We used GM to investigate the relationships between being overweight and lumbar sagittal configuration. Age, sex, weight, height and BMI of 152 consecutive spine MRI were retrospectively collected. 66 landmarks were digitized on each midsagittal T2-weighted images. Procrustes superimpositions, Principal Component analysis (PCA), Canonical Variate analysis (CVA), and other multivariate techniques were used to find mean shape consensus and possible shape-BMI covariations.A strong correlation between sagittal lumbar shape and BMI was found. Morphological changes such as telescoping, lordosis and variations in vertebral-disk shape were found to be related with BMI, as well as other common variables such as sex and age. GM helps understand the way in which being overweight influences the lumbar shape. These techniques offer a powerful, reproducible and dynamically interactive method to explore spine shape, with diagnostic, therapeutic and preventive implications. A more extensive use of Geometric Morphometrics in spine shape investigation is proposed.

Keywords: Lumbar â?? Spine â?? Sagittal balance â?? Geometric morphometrics â?? Procrustes superimposition â?? Body Mass Index