title: Biomechanical characteristics of the porcine denticulate ligament in different vertebral levels of the cervical spine-preliminary results of an experimental study.
abstract: BACKGROUND
  Few studies exist on the mechanical properties of denticulate ligaments and none report the variation in these properties at different levels of the spine. The aim of this study was to perform an experimental determination of load-extension and stress-strain characteristics of the denticulate ligament and to establish if their properties change at different vertebral levels of the cervical spine.
  
  
  METHODS
  The study was carried out on a total of 98 porcine denticulate ligament samples dissected from seven fresh porcine cervical spinal cord specimens. All of the samples were subjected to an uniaxial tensile test at a speed of 2mm/min, during which the load-extension characteristics were registered.
  
  
  RESULTS
  The analysis revealed a decrease of the failure force in the caudal orientation indicated by significant differences between the C1 (1.04±0.41N) and C7 (0.55±0.12N) vertebral levels (P=0.037). The average ultimate force that broke the denticulate ligaments was 0.88N. The mean value of Young׳s modulus was 2.06MPa with a minimum of 1.31MPa for C7 and maximum of 2.46MPa for C5.
  
  
  CONCLUSIONS
  The values of the denticulate ligament failure force in samples from different cervical vertebrae levels differ significantly. The presented data should be taken into consideration during numerical modelling of the human cervical spinal cord.
authors.affiliation: Institute of Product and Process Innovation, Leuphana University Lueneburg, Germany; Division of Biomedical Engineering and Experimental Mechanics, Wroclaw University of Technology, Wroclaw, Poland. Electronic address: polak@leuphana.de.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Polak
authors.affiliation: Department of Neurosurgery, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Czyż
authors.affiliation: Division of Biomedical Engineering and Experimental Mechanics, Wroclaw University of Technology, Wroclaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Ścigała
authors.affiliation: Department of Neurosurgery, Wroclaw Medical University, Wroclaw, Poland.
authors.forename: Włodzimierz
authors.initials: W
authors.lastname: Jarmundowicz
authors.affiliation: Division of Biomedical Engineering and Experimental Mechanics, Wroclaw University of Technology, Wroclaw, Poland.
authors.forename: Romuald
authors.initials: R
authors.lastname: Będziński
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002574:Cervical Vertebrae; D006801:Humans; D008022:Ligaments; D008422:Materials Testing; D055595:Mechanical Phenomena; D013314:Stress, Mechanical; D013552:Swine; D013718:Tensile Strength
keywords: Cervical spinal cord; Denticulate ligament; Experimental study; Mechanical properties; Numerical modelling; Spinal cord; Uniaxial tensile test