Spinous process morphology: the effect of ageing through adulthood on spinous process size and relationship to sagittal alignment

Abstract

This study demonstrates that the dimensions of the LSP change with age. Increases in LSP height and even more impressive increases in LSP width occur with advancing age. There is an inverse relationship between lumbar lordosis and LSP height.

An increase in height of spinous process is associated with decreased heights of intervertebral disc and vertebral body in the degenerative process of lumbar spine

“…Our hypothesis explaining the result of the increased heights of the L4 and L5 spinous processes with age may be a secondary adaptive response to increase their mechanical properties after sharing a compressive load from anterior structures, according to Wolf's Law [1,9]. Because we found that the spinous process height was increased after the intervertebral disc space narrowed and the vertebral body height was decreased, we think that the adaptive response occurred to act as a tethering structure to prevent hyperextension of the lumbar spine and to increase the stiffness and stability.…”

“…However, some literature published in English mentions changes in spinous process morphology with age [9,10]. Aylott et al [9] measured the height and width of lumbar spinous processes with CT and showed significant increases that were correlated with age. Their study also showed a negative correlation between the height of the spinous processes and the degree of the lumbar lordosis.…”

“…Spinous process abutment can be explained by both increases in the height of the spinous processes and decreases in the distance of the interspinous space with age [8,20]. Although Aylott et al [9] and Sartoris et al [20] describe that the spinous process height increases with aging, they did not measure the vertebral body height, and hardly mentioned the degenerative process of the lumbar spine. Our results show that the height of the intervertebral disc becomes low from 40s or 50s, the height of the vertebral body becomes low from 50s or 60s, and the height of the spinous process becomes high from 60s or 70s, which are new findings.…”

“…Many reports have been published in this regard [1,[3][4][5][6]. Furthermore, to a considerable extent, the heights of the vertebral body and spinous process may indicate in the degenerative changes in the lumbar vertebrae [1,[7][8][9]. A decrease in vertebral body height is mainly caused by a decrease in bone content and bone density due to aging, whereas an increase in the height of the spinous process is mainly attributable to the formation of enthesopathy spurs [1,10].…”

“…A decrease in vertebral body height is mainly caused by a decrease in bone content and bone density due to aging, whereas an increase in the height of the spinous process is mainly attributable to the formation of enthesopathy spurs [1,10]. However, very few reports have been published on the actual measurement of the heights of the intervertebral body and spinous process in this regard [8][9][10]. We determined the heights of the 4th (L4) and 5th (L5) lumbar vertebrae, the spinous processes in L4 and L5, and the vertebral discs between L4/5 and L5/S1 with computed tomography (CT) to investigate how the heights of intervertebral disc, vertebral body, and spinous process are related to aging and gender differences.…”