Changes in L4/5 Intervertebral Foramen Bony Morphology with Age.

The purpose of this study was to explore the morphological changes in L4/5 intervertebral foramen with age using a digital method. The closed boundaries of the intervertebral foramen (IGES) in different sagittal slices (inside, middle and outside) were obtained from Mimics, and then imported to a custom-written program, which provided quantitative distance between the nerve root and the closed curves. The quantitative information of each age group was used to produce radar chart and line chart for morphological and statistical analyses. Overall, the intervertebral foramen changes mainly occurred in the inner part from middle age to old age. The foraminal height decreased with age in the inside sagittal slice, while no significant difference was found in the middle sagittal slice or the outside sagittal slice. The foraminal width showed no decrease in each age group or each sagittal plane. The present study described foraminal geometry of asymptomatic males in different sagittal slices with age. This information enhances the knowledge of anatomical changes in intervertebral foramen with age, which provides better understanding of the pathology of intervertebral foramen diseases.