title: Effects of advanced age on the morphometry and degenerative state of the cervical spine in a rat model.
abstract: Aging causes changes in the geometry of the human cervical spine that may influence the tissue response to applied loads. Rat models are often used to study spinal cord injuries (SCI) and have the potential to enhance our understanding of the effect of age on SCI. The goal of this study was to characterize the morphometry and degenerative state of the cervical spine in Fisher 344 rats, and to determine the influence of age on these variables. Fifteen rats were split into three age groups: young adult (3 months of age), aged (12-18 months) and geriatric (30 months). Following tissue harvest we used a μCT scanner to image the cervical and upper thoracic spine from each specimen. Analysis software was used to measure variables including canal pinch diameter (the most rostral point on the dorsal aspect of a vertebral body to the most caudal aspect of the lamina on the immediately rostral vertebra), vertebral canal depth, width, and area, vertebral body height, depth, width, and area, and intervertebral disc thickness. Orthopaedic surgeons used midsagittal images to rate the degenerative state of the intervertebral discs. For all measures except disc thickness there was a significant increase (mean (SD) = 15.0 (9.7)%) for the aged compared to young specimens (P < 0.05). There were significant differences between the aged and geriatric specimens for only vertebral body depth (P = 0.016) and area (P = 0.020). Intervertebral disc degeneration was significantly greater on the ventral aspect of the spinal column (P < 0.001), with a trend toward increased degeneration in the geriatric specimens (P = 0.069). The results suggest that age-related morphometric differences may need to be accounted for in experimental aging models of SCI in rats.
authors.affiliation: Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, Ontario, Canada. actlaing@uwaterloo.ca
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Laing
authors.forename: Riley
authors.initials: R
authors.lastname: Cox
authors.forename: Wolfram
authors.initials: W
authors.lastname: Tetzlaff
authors.forename: Thomas
authors.initials: T
authors.lastname: Oxland
mesh_terms: D000367:Age Factors; D000375:Aging / Q000473:pathology*; D000818:Animals; D000886:Anthropometry; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000473:pathology*; D007403:Intervertebral Disc / Q000000981:diagnostic imaging / Q000473:pathology*; D055959:Intervertebral Disc Degeneration / Q000000981:diagnostic imaging / Q000473:pathology* / Q000503:physiopathology; D008297:Male; D023421:Models, Animal; D011857:Radiographic Image Interpretation, Computer-Assisted; D051381:Rats; D011916:Rats, Inbred F344; D055114:X-Ray Microtomography