Design and Fabrication of a Drop Tower Testing Apparatus to Investigate the Impact Behavior of Spinal Motion Segments

Document Type : RESEARCH PAPER

Authors

Biomechanical Engineering Group, Biomedical Engineering Department, Amirkabir University of Technology, Tehran, Iran

Abstract

Background: The vertebral column is the second most common fracture site in individuals with high-grade osteoporosis
(30–50%). Most of these fractures are caused by falls. This information reveals the importance of considering impact
loading conditions of spinal motion segments, while no commercial apparatus is available for this purpose. Therefore,
the goal was set to fabricate an impact testing device for the measurement of impact behavior of the biological tissues.
Methods: In the present study, first, a drop-weight impact testing apparatus was designed and fabricated to record both
force and displacement at a sample rate of 100 kHz. A load cell was placed under the sample, and an accelerometer
was located on the impactor. Previous devices have mostly measured the force and not the deformation. Thereafter,
the effect of high axial compression load was investigated on a biological sample, i.e., the lumbar motion segment, was
investigated. To this end, nine ovine segments subjected to vertical impact load were examined using the fabricated
device, and the mechanical properties of the lumbar segments were extracted and later compared with quasi-static
loading results.
Results: The results indicated that the specimen stiffness and failure energy in impact loading were higher than those
in the quasi-static loading. In terms of the damage site, fracture mainly occurred in the body of the vertebra during
impact loading; although, during quasi-static loading, the fracture took place in the endplates.
Conclusion: The present study introduces an inexpensive drop-test device capable of recording both the force and
the deformation of the biological specimens when subjected to high-speed impacts. The mechanical properties of the
spinal segments have also been extracted and compared with quasi-static loading results.
Level of evidence: V

Keywords

References

1. Lee S, Novitskaya EE, Reynante B, Vasquez J, Urbaniak
R, Takahashi T, et al. Impact testing of structural
biological materials. Mater Sci Eng C Mater Biol Appl.
2011; 31(4):730-9.
2. Verteramo A, Seedhom B. Effect of a single impact
loading on the structure and mechanical properties of
articular cartilage. J Biomech. 2007; 40(16):3580-9.
3. ASTM American Society for Testing and Materials.
Standard test methods for determining the Izod
pendulum impact resistance of plastics. ASTM
international; 2010.
4. Mills NJ. The mechanism of brittle fracture in notched
impact tests on polycarbonate. J Mater Sci. 1976;
11(2):363-75.
5. Kurishita H, Kayano H, Narui M, Yamazaki M, Kano Y,
Shibahara I. Effects of V-Notch Dimensions on Charpy
Impact Test Results for Differently Sized Miniature
Specimens of Ferritic Steel. Mater Trans. 1993;
34(11):1042-1052.
6. Burgin LV, Aspden RM. A drop tower for controlled
impact testing of biological tissues. Med Eng Phys.
2007; 29(4):525-30.
7. Burgin LV, Aspden RM. Impact testing to determine
the mechanical properties of articular cartilage in
isolation and on bone. J Mater Sci Mater Med. 2008;
19(2):703-11.
8. Cooper C, Atkinson EJ, MichaelO’Fallon W, and Melton
III JL. Incidence of clinically diagnosed vertebral
fractures: a population- based study in Rochester,
Minnesota. JBMR. 1992; 7(2):221–227.
9. Myers ER, Wilson SE. Biomechanics of osteoporosis
and vertebral fracture. Spine J. 1997; 22(24):25S–31S.
10. Dudli S, Haschtmann D, Ferguson SJ. Prior storage
conditions and loading rate affect the in vitro fracture
response of spinal segments under impact loading. J
Biomech.2011; 44(13):2351-5.
11. Dudli S, Haschtmann D, Ferguson SJ. Fracture of the
vertebral endplates, but not equienergetic impact
load, promotes disc degeneration in vitro. J Orthop.
2012; 30(5):809-16.
12. Wilson S, Alkalay RN, Myers BR. Effect of the
degenerative state of the intervertebral disk on the
impact characteristics of human spine segments.
Front bioeng biotechnol. 2013; 1:16.
13. Kasra M, Shirazi-Adl A, Drouin G. Dynamics of human
lumbar intervertebral joints. Experimental and finiteelement
investigations. Spine J. 1992; 17(1):93-102.
14. Nikkhoo M, Wang J-L, Parnianpour M, El-Rich M, Khalaf
K. Biomechanical response of intact, degenerated and
repaired intervertebral discs under impact loading–
Ex-vivo and In-Silico investigation. J Biomech. 2018;
70:26-32.
15. Banthia N, Mindess S, Bentur A, Pigeon M. Impact
testing of concrete using a drop-weight impact
machine. Exp Mech. 1989; 29(1):63-9.
16. Duenwald SE, Vanderby R, Lakes RS. Stress relaxation
and recovery in tendon and ligament: experiment and
modeling. Biorheology. 2010; 47(1):1-4.
17. Kemper A, McNally C, Manoogian S, McNeely D, Duma
S, editors. Stiffness properties of human lumbar
intervertebral discs in compression and the influence
of strain rate. Proceedings of the 20th Enhanced
Safety of Vehicles Conference 2013.
18. Yingling VR, Callaghan JP, McGill SM. Dynamic loading
affects the mechanical properties and failure site of
porcine spines. Clin Biomech (Bristol, Avon). 1997;
12(5):301-5.
19. Jamison D, Cannella M, Pierce EC, Marcolongo MS. A
comparison of the human lumbar intervertebral disc
mechanical response to normal and impact loading
conditions. J Biomech Eng. 2013; 135(9).
The Archives of Bone and Joint Surgery
Volume 8, Issue 6
November and December 2020
Pages 682-688

Files

History

  • Receive Date: 19 January 2020
  • Revise Date: 21 May 2020
  • Accept Date: 10 June 2020

Share

How to cite

Statistics