Annals of Biomedical Engineering

, Volume 46, Issue 11, pp 1911–1920 | Cite as

Effects of Level, Loading Rate, Injury and Repair on Biomechanical Response of Ovine Cervical Intervertebral Discs

  • Rose G. Long
  • Ivan Zderic
  • Boyko Gueorguiev
  • Stephen J. Ferguson
  • Mauro Alini
  • Sibylle Grad
  • James C. IatridisEmail author


A need exists for pre-clinical large animal models of the spine to translate biomaterials capable of repairing intervertebral disc (IVD) defects. This study characterized the effects of cervical spinal level, loading rate, injury and repair with genipin-crosslinked fibrin (FibGen) on axial and torsional mechanics in an ovine cervical spine model. Cervical IVDs C2–C7 from nine animals were tested with cyclic tension–compression (− 240 to 100 N) and cyclic torsion (± 2° and ± 4°) tests at three rates (0.1, 1 and 2 Hz) in intact, injured and repaired conditions. Intact IVDs from upper cervical levels (C2–C4) had significantly higher torque range and torsional stiffness and significantly lower axial range of motion (ROM) and tensile compliance than IVDs from lower cervical levels (C5–C7). A tenfold increase in loading rate significantly increased torque range and torsional stiffness 4–8% (depending on amplitude) (p < 0.001). When normalized to intact, FibGen significantly restored torque range (FibGen: 0.96 ± 0.14, Injury: 0.88 ± 0.14, p = 0.03) and axial ROM (FibGen: 1.00 ± 0.05, Injury: 1.04 ± 0.15, p = 0.02) compared to Injury, with a values of 1 indicating full repair. Cervical spinal level must be considered for controlling biomechanical evaluations, and FibGen restored some torsional and axial biomechanical properties to intact levels.


Hydrogel Biomechanics Tissue engineering Annulus fibrosus Large animal In vitro 



No competing financial interests exist. This Research was funded by National Institute for Arthritis and Musculoskeletal and Skin Diseases (R01AR057397), the Whitaker Foundation, and a Collaborative Research Partner Program Grant on Annulus Fibrosus Rupture from the AO Foundation, Davos, Switzerland. The authors gratefully acknowledge important technical contributions of Patrick Hörnlimann and Dieter Wahl.


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Copyright information

© Biomedical Engineering Society 2018

Authors and Affiliations

  1. 1.AO Research Institute DavosDavosSwitzerland
  2. 2.Leni & Peter W. May Department of OrthopaedicsIcahn School of Medicine at Mount SinaiNew YorkUSA
  3. 3.Institute for BiomechanicsETH ZurichZurichSwitzerland

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