Poroelastic Analysis of Lumbar Spinal Stability in Combined Compression and Anterior Shear

Lee, K K; Teo, Ee-Chon

doi:10.1097/01.bsd.0000109835.59382.9c

Cited by 21 publications

(8 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These findings, in agreement with the reported effects of strain (Lee and Teo, 2004) and loading frequency (Iatridis et al, 1997; Kuo and Wang, 2010) on the permeability of the disk tissues, suggest disk hydration plays a significant role in the immediate response of the spine to sudden impact. Under impact loading, our computational model predicted the immediate (up to 200 ms) response of the FSU resulting in a constant pore pressure within the nucleus, rather than the solid matrix of the disk, supports the compressive load for the duration of the impact (Lee et al, 2000).…”

Section: Discussionsupporting

confidence: 91%

Effect of the Degenerative State of the Intervertebral Disk on the Impact Characteristics of Human Spine Segments

Wilson

Alkalay

Myers

2013

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

Models of the dynamic response of the lumbar spine have been used to examine vertebral fractures (VFx) during falls and whole body vibration transmission in the occupational setting. Although understanding the viscoelastic stiffness or damping characteristics of the lumbar spine are necessary for modeling the dynamics of the spine, little is known about the effect of intervertebral disk degeneration on these characteristics at high loading rates. We hypothesize that disk degeneration significantly affects the viscoelastic response of spinal segments to high loading rate. We additionally hypothesize the lumbar spine stiffness and damping characteristics are a function of the degree of preload. A custom, pendulum impact tester was used to impact 19 L1–L3 human spine segments with an end mass of 20.9 kg under increasing preloads with the resulting force response measured. A Kelvin–Voigt model, fitted to the frequency and decay response of the post-impact oscillations was used to compute stiffness and damping constants. The spine segments exhibited a second-order, under-damped response with stiffness and damping values of 17.9–754.5 kN/m and 133.6–905.3 Ns/m respectively. Regression models demonstrated that stiffness, but not damping, significantly correlated with preload (p < 0.001). Degenerative disk disease, reflected as reduction in magnetic resonance T2 relaxation time, was weakly correlated with change in stiffness at low preloads. This study highlights the need to incorporate the observed non-linear increase in stiffness of the spine under high loading rates in dynamic models of spine investigating the effects of a fall on VFx and those investigating the response of the spine to vibration.

show abstract

Section: Discussionsupporting

confidence: 91%

Effect of the Degenerative State of the Intervertebral Disk on the Impact Characteristics of Human Spine Segments

Wilson

Alkalay

Myers

2013

Front. Bioeng. Biotechnol.

View full text Add to dashboard Cite

show abstract

“…Unlike previous models [28,48,49] our model took the intradiscal pressure in the unloaded state was to be non-zero, and it's predictions showed that it maintained a finite value even after hours of loading. This finding is in agreement with the pressures measured in vivo by Nachemson and Morris [11] and Wilke et al [5].…”

Section: Discussionmentioning

confidence: 92%

Osmoviscoelastic finite element model of the intervertebral disc

et al. 2006

View full text Add to dashboard Cite

Intervertebral discs have a primarily mechanical role in transmitting loads through the spine. The disc is subjected to a combination of elastic, viscous and osmotic forces; previous 3D models of the disc have typically neglected osmotic forces. The fibrilreinforced poroviscoelastic swelling model, which our group has recently developed, is used to compute the interplay of osmotic, viscous and elastic forces in an intervertebral disc under axial compressive load. The unloaded 3D finite element mesh equilibrates in a physiological solution, and exhibits an intradiscal pressure of about 0.2 MPa. Before and after axial loading the numerically simulated hydrostatic pressure compares well with the experimental ranges measured. Loading the disc decreased the height of the disc and results in an outward bulging of the outer annulus. Fiber stresses were highest on the most outward bulging on the posterior-lateral side. The osmotic forces resulted in tensile hoop stresses, which were higher than typical values in a non-osmotic disc. The computed axial stress profiles reproduced the main features of the stress profiles, in particular the characteristic posterior and anterior stress which were observed experimentally.

show abstract

“…The influence of long-term compression loading on nutrient concentrations is investigated by alterations in the disc geometry and tissue diffusivities associated with fluid loss. Under constant compression loading for about 2-8 h (Koeller et al, 1984;Lee and Teo, 2004;McNally and Adams, 1992;Shirazi-Adl, 1992), fluid losses reaching 11% and 20% of the initial disc fluid volume are assumed (Argoubi and Shirazi-Adl, 1996). Accordingly, loss of fluid content in each region and deformed shapes of the disc (Fig.…”

Section: Mechanical Loadmentioning

confidence: 99%

Computation of coupled diffusion of oxygen, glucose and lactic acid in an intervertebral disc

Soukane

Shirazi-Adl

Urban

2007

Journal of Biomechanics

103

View full text Add to dashboard Cite

Poroelastic Analysis of Lumbar Spinal Stability in Combined Compression and Anterior Shear

Abstract: The predicted results using poroelastic elements provide new insight into the IVD in providing the spinal stiffness under combined loading.

Cited by 21 publications

References 25 publications

Effect of the Degenerative State of the Intervertebral Disk on the Impact Characteristics of Human Spine Segments

Effect of the Degenerative State of the Intervertebral Disk on the Impact Characteristics of Human Spine Segments

Osmoviscoelastic finite element model of the intervertebral disc

Computation of coupled diffusion of oxygen, glucose and lactic acid in an intervertebral disc

Contact Info

Product

Resources

About