Vertebral cross-sectional growth: A predictor of vertebral wedging in the immature skeleton.

Ervin Poorghasamians,Tishya A. L. Wren,Skorn Ponrartana,Vicente Gilsanz,Patricia C. Aggabao,Robert Daniel Blank

doi:10.1371/journal.pone.0190225

Ervin Poorghasamians, Tishya A. L. Wren + Show 4 more

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https://doi.org/10.1371/journal.pone.0190225

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Abstract

The degree of vertebral wedging, a key structural characteristic of spinal curvatures, has recently been found to be negatively related to vertebral cross-sectional area (CSA). The purpose of this longitudinal study was to examine the relation between vertebral cross-sectional growth and vertebral wedging progression within the immature lumbar spine. Using magnetic resonance imaging (MRI), we analyzed the potential association between increases in lumbar vertebral CSA and changes in L5 vertebral wedging in 27 healthy adolescent girls (ages 9–13 years) twice within a two-year period. Vertebral CSA growth was negatively associated with changes in posteroanterior vertebral wedging (r = -0.61; p = 0.001). Multiple regression analysis showed that this relation was independent of gains in age, height, and weight. When compared to the 14 girls whose vertebral wedging progressed, the 13 subjects whose vertebral wedging decreased had significantly greater vertebral cross-sectional growth (0.39 ± 0.25 vs. 0.75 ± 0.23 cm2; p = 0.001); in contrast, there were no significant differences in increases in age, height, or weight between the two groups. Changes in posteroanterior vertebral wedging and the degree of lumbar lordosis (LL) positively correlated (r = 0.56, p = 0.002)—an association that persisted even after adjusting for gains in age, height, and weight. We concluded that in the immature skeleton, vertebral cross-sectional growth is an important determinant of the plasticity of the vertebral body; regression of L5 vertebral wedging is associated with greater lumbar vertebral cross-sectional growth, while progression is the consequence of lesser cross-sectional growth.

Highlights

Just as the term plasticity in engineering exemplifies the ability of solid material to undergo deformation in response to load, skeletal plasticity describes the facility of growing bone to alter modelling as a consequence of mechanical stresses [1]
We recently found a negative correlation between values for vertebral cross-sectional area (CSA) and both lateral vertebral wedging in scoliosis and posteroanterior vertebral wedging within the lumbar curve [4]—relations that were independent of age and body size
We recently found that smaller vertebral CSA is associated with greater vertebral wedging in scoliosis and lumbar lordosis curves [4]

Summary

Introduction

Just as the term plasticity in engineering exemplifies the ability of solid material to undergo deformation in response to load, skeletal plasticity describes the facility of growing bone to alter modelling as a consequence of mechanical stresses [1]. Vertebral cross-sectional growth: A predictor of vertebral wedging in the immature skeleton deformations that adult vertebrae sustain under load, asymmetrical vertebral growth in children has the capacity to change shape in response to mechanical stresses [2,3]. We recently found a negative correlation between values for vertebral cross-sectional area (CSA) and both lateral vertebral wedging in scoliosis and posteroanterior vertebral wedging within the lumbar curve [4]—relations that were independent of age and body size. Since vertebral CSA is a major determinant of spinal flexibility and strength [11,12,13,14,15], asymmetrical vertebral growth secondary to unbalanced axial load would be most prominent in the presence of small vertebral cross-sectional dimensions

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