title: Morphological changes of the caudal cervical intervertebral foramina due to flexion-extension and compression-traction movements in the canine cervical vertebral column.
abstract: BACKGROUND
  Previous studies in humans have reported that the dimensions of the intervertebral foramina change significantly with movement of the spine. Cervical spondylomyelopathy (CSM) in dogs is characterized by dynamic and static compressions of the neural components, leading to variable degrees of neurologic deficits and neck pain. Studies suggest that intervertebral foraminal stenosis has implications in the pathogenesis of CSM. The dimensions of the cervical intervertebral foramina may significantly change during neck movements. This could have implication in the pathogenesis of CSM and other diseases associated with radiculopathy such as intervertebral disc disease. The purpose of this study was to quantify the morphological changes in the intervertebral foramina of dogs during flexion, extension, traction, and compression of the canine cervical vertebral column. All vertebral columns were examined with magnetic resonance imaging prior to biomechanic testing. Eight normal vertebral columns were placed in Group 1 and eight vertebral columns with intervertebral disc degeneration or/and protrusion were assigned to Group 2. Molds of the left and right intervertebral foramina from C4-5, C5-6 and C6-7 were taken during all positions and loading modes. Molds were frozen and vertical (height) and horizontal (width) dimensions of the foramina were measured. Comparisons were made between neutral to flexion and extension, flexion to extension, and traction to compression in neutral position.
  
  
  RESULTS
  Extension decreased all the foraminal dimensions significantly, whereas flexion increased all the foraminal dimensions significantly. Compression decreased all the foraminal dimensions significantly, and traction increased the foraminal height, but did not significantly change the foraminal width. No differences in measurements were seen between groups.
  
  
  CONCLUSIONS
  Our results show movement-related changes in the dimensions of the intervertebral foramina, with significant foraminal narrowing in extension and compression.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L. Tharp St, Columbus, OH, 43210, USA. renatomoran@hotmail.com.|Department of Clinical and Surgery, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Campos dos Goytacazes, RJ, 28013-602, Brazil. renatomoran@hotmail.com.
authors.forename: Renato M
authors.initials: RM
authors.lastname: Ramos
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, 601 Vernon L. Tharp St, Columbus, OH, 43210, USA. dacosta.6@osu.edu.
authors.forename: Ronaldo C
authors.initials: RC
authors.lastname: da Costa
authors.affiliation: Department of Clinical and Surgery, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Av. Alberto Lamego, 2000, Campos dos Goytacazes, RJ, 28013-602, Brazil. lacerdavet@uol.com.br.
authors.forename: Andre L A
authors.initials: AL
authors.lastname: Oliveira
authors.affiliation: Engineering Center for Orthopedic Research Excellence, The University of Toledo Health Science Campus, 3000 Arlington Ave, Toledo, OH, USA. mannu624@gmail.com.
authors.forename: Manoj K
authors.initials: MK
authors.lastname: Kodigudla
authors.affiliation: Engineering Center for Orthopedic Research Excellence, The University of Toledo Health Science Campus, 3000 Arlington Ave, Toledo, OH, USA. Vijay.Goel@utoledo.edu.
authors.forename: Vijay K
authors.initials: VK
authors.lastname: Goel
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002102:Cadaver; D002574:Cervical Vertebrae / Q000033:anatomy & histology* / Q000502:physiology*; D004285:Dogs / Q000033:anatomy & histology* / Q000502:physiology*; D007403:Intervertebral Disc / Q000033:anatomy & histology* / Q000502:physiology*; D009068:Movement