The unconfined compression and tension experiments of the intervertebral disc were conducted by applying an optimized digital image correlation technique, and the internal strain distribution was analysed for the disc. It was found that the axial strain values of different positions increased obviously with the increase in loads, while inner annulus fibrosus and posterior annulus fibrosus experienced higher axial strains than the outer annulus fibrosus and anterior annulus fibrosus. Deep annulus fibrosus exhibited higher compressive and tensile axial strains than superficial annulus fibrosus for the anterior region, while there was an opposite result for the posterior region. It was noted that all samples demonstrated a nonlinear stress–strain profile in the process of deforming, and an elastic region was shown once the sample was deformed beyond its toe region.
HollingsworthNTWagnerDR. The stress and strain states of the posterior annulus under flexion. Spine2012; 37(18): 1134–1139.
2.
KimKLeeSKKimYH. The biomechanical effects of variation in the maximum forces exerted by trunk muscles on the joint forces and moments in the lumbar spine: a finite element analysis. Proc IMechE, Part H: J Engineering in Medicine2010; 224(10): 1165–1174.
3.
CassidyJJHiltnerABaerE. The response of the hierarchical structure of the intervertebral disc to uniaxial compression. J Mater Sci: Mater M1990; 1(2): 69–80.
4.
NikkhooMHsuYCHaghpanahiM. A meta-model analysis of a finite element simulation for defining poroelastic properties of intervertebral discs. Proc IMechE, Part H: J Engineering in Medicine2013; 227(6): 672–682.
5.
FaganMJJulianSSiddallDJ. Patient-specific spine models. Part 1: finite element analysis of the lumbar intervertebral disc – a material sensitivity study. Proc IMechE, Part H: J Engineering in Medicine2002; 216(5): 299–314.
6.
Shirazi AdlSAShrivastavaSCAhmedAM. Stress analysis of the lumbar disc-body unit in compression. A three-dimensional nonlinear finite element study. Spine1984; 9(2): 120–134.
7.
SpilkerRLJakobsDMSchultzAB. Material constants for a finite element model of the intervertebral disk with a fiber composite annulus. J Biomech Eng: T ASME1986; 108(1): 1–11.
8.
MizrahiJSilvaMJHayesWC. Finite element stress analysis of simulated metastatic lesions in the lumbar vertebral body. J Biomed Eng1992; 14(6): 467–475.
9.
SunWLiH. An approach to assessment of strain and stress distribution of intervertebral disc using CT images. In: Proceedings of IEEE/ICME international conference on complex medical engineering, Beijing, China, 23–27 May 2007, pp.766–769. New York: IEEE.
10.
SchmidtHHeuerFWilkeHJ. Dependency of disc degeneration on shear and tensile strains between annular fiber layers for complex loads. Med Eng Phys2009; 31(6): 642–649.
11.
ChuJYSkrzypiecDPollintineP. Can compressive stress be measured experimentally within the annulus fibrosus of degenerated intervertebral discs?Proc IMechE, Part H: J Engineering in Medicine2008; 222(2): 161–170.
McNallyDSAdamsMAGoodshipAE. Can intervertebral disc prolapse be predicted by disc mechanics?Spine1993; 18(11): 1525–1530.
14.
AdamsMAFreemanBJCMorrisonHP. Mechanical initiation of intervertebral disc degeneration. Spine2000; 25(13): 1625–1636.
15.
EdwardsWTOrdwayNRZhengY. Peak stresses observed in the posterior lateral anulus. Spine2001; 26(16): 1753–1759.
16.
WilkeHJKrischakSClaesL. Biomechanical comparison of calf and human spines. J Orthop Res1996; 14(3): 500–503.
17.
McNallyDSAdamsMA. Internal intervertebral disc mechanics as revealed by stress profilometry. Spine1992; 17(1): 66–73.
18.
RyanGPanditAApatsidisD. Stress distribution in the intervertebral disc correlates with strength distribution in subdiscal trabecular bone in the porcine lumbar spine. Clin Biomech2008; 23(7): 859–869.
19.
O’ConnellGDJohannessenWVresilovicEJ. Human internal disc strains in axial compression measured noninvasively using magnetic resonance imaging. Spine2007; 32(25): 2860–2868.
20.
O’ConnellGDVresilovicEJ. Human intervertebral disc internal strain in compression: the effect of disc region, loading position, and degeneration. J Orthop Res2011; 29(4): 547–555.
21.
YinglingVRCallaghanJP. The porcine cervical spine as a model of the human lumbar spine: an anatomical, geometric, and functional comparison. J Spinal Disord1999; 12(5): 415–423.
22.
OxlandTRPanjabiMMSouthernEP. An anatomic basis for spinal instability: a porcine trauma model. J Orthop Res1991; 9(3): 452–462.
23.
GaoLLZhangCQDongLM. Description of depth-dependent nonlinear viscoelastic behavior for articular cartilage in unconfined compression. Mat Sci Eng C2012; 32(2): 119–125.
24.
ZhangCQGaoLLDongLM. Depth-dependent axial strain of articular cartilage under sliding load by the optimized digital image correlation technique. Mat Sci Eng C2012; 32(8): 2390–2395.
25.
GregoryDECallaghanJP. A comparison of uniaxial and biaxial mechanical properties of the annulus fibrosus: a porcine model. J Biomech Eng2011; 133(2): 024503.1–024503.5.
26.
GregoryDECallaghanJP. An examination of the mechanical properties of the annulus fibrosus: the effect of vibration on the intra-lamellar matrix strength. Med Eng Phys2012; 34(4): 472–477.
27.
EbaraSIatridisJCSettonLA. Tensile properties of nondegenerate human lumbar anulus fibrosus. Spine1996; 21(4): 452–461.
28.
HolzapfelGASchulze BauerCAJFeiglG. Single lamellar mechanics of the human lumbar anulus fibrosus. Biomech Model Mechan2005; 3(3): 125–140.
29.
CausaFMantoLBorzacchielloA. Spatial and structural dependence of mechanical properties of porcine intervertebral disc. J Mater Sci Mater Med2002; 13(12): 1277–1280.
30.
KellerTSHolmSHHanssonTH. 1990 Volvo award in experimental studies: the dependence of intervertebral disc mechanical properties on physiologic conditions. Spine1990; 15(8): 751–761.
