title: Biomechanical evaluation of the stabilizing function of the atlantoaxial ligaments under shear loading: a canine cadaveric study.
abstract: OBJECTIVE
  To evaluate the stabilizing function of atlanto-axial ligaments in dogs.
  
  
  METHODS
  Cadaveric biomechanical study.
  
  
  METHODS
  Beagle dog cadavers (n = 10).
  
  
  METHODS
  The craniocervical region was collected from 10 Beagle cadavers, and the occipito-atlanto-axial region was prepared and freed from the surrounding muscles. Care was taken to preserve integrity of the atlantoaxial ligaments and atlantoaxial joint capsule. The atlanto-occipital joints were blocked with 2 diverging transarticular 1.8 mm positive threaded K-wires. Specimen extremities were embedded in polymethylmethacrylate (PMMA) and mounted on a simulator testing shear load at the atlantoaxial joint. Range of motion (ROM) and neutral zone (NZ) were determined with all ligaments intact, after cutting the apical ligament, both alar ligaments, the transverse ligaments and finally after cutting the dorsal atlantoaxial ligament.
  
  
  RESULTS
  ROM increased similarly and stepwise during testing. The most significant increase was observed after transection of the alar ligaments.
  
  
  CONCLUSIONS
  The alar ligaments seem to be the most important ligamentous structures for stabilization of the atlantoaxial joint under shear load.
authors.affiliation: Department Clinical Veterinary Medicine, Vetsuisse Faculty, Institute for Surgical Technology and Biomechanics, University of Bern, Bern, Switzerland.
authors.forename: Katrine
authors.initials: K
authors.lastname: Reber
authors.forename: Alexander
authors.initials: A
authors.lastname: Bürki
authors.forename: Nuria
authors.initials: N
authors.lastname: Vizcaino Reves
authors.forename: Michael
authors.initials: M
authors.lastname: Stoffel
authors.forename: Karine
authors.initials: K
authors.lastname: Gendron
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Ferguson
authors.forename: Franck
authors.initials: F
authors.lastname: Forterre
mesh_terms: D000818:Animals; D001268:Atlanto-Axial Joint / Q000033:anatomy & histology* / Q000502:physiology*; D001696:Biomechanical Phenomena; D002102:Cadaver; D004285:Dogs / Q000033:anatomy & histology / Q000502:physiology*; D005260:Female; D008023:Ligaments, Articular / Q000033:anatomy & histology* / Q000502:physiology*; D008297:Male; D016059:Range of Motion, Articular; D033081:Shear Strength