Measurement of Cadaver Lumbar Spine Motion Segment Stiffness

Brown, Mark D.; Holmes, David; Heiner, Anneliese D.

doi:10.1097/00007632-200205010-00006

Cited by 61 publications

(27 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore it does not simulate the multiphase behavioral changes occurring within the IVD. The degenerative model is however in very close agreement with previous experimental and numerical studies reporting an initial reduction in motion segment compressive stiffness following early stage IVD degeneration [4,5,31]. In addition, our reported reduction in endplate bulge and increase in IVD von Mises stress due to the reduction in the incompressibility characteristics of the nucleus following IVD degeneration is in agreement with previous findings [13,33].…”

Section: Discussionsupporting

confidence: 92%

“…Results from such studies have shown that single segment partial fill cement augmentation strategies are effective in restoring motion segment stiffness to pre-damage levels for slightly damaged segments, but are ineffective in restoring stiffness for moderately and severely damaged segments [12,17]. In the current study we hypothesize that early stage disc degeneration, shown to reduce motion segment stiffness [4,5,31], will considerably alter treated and adjacent-level stress distributions when compared to normal IVD segments following cement augmentation repair. Specifically this study aims to: (1) simulate trabecular bone damage in a thoracic motion segment (VB ?…”

Section: Introductionmentioning

confidence: 74%

See 1 more Smart Citation

Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

2008

View full text Add to dashboard Cite

Vertebroplasty and kyphoplasty have been reported to alter the mechanical behavior of the treated and adjacent-level segments, and have been suggested to increase the risk for adjacent-level fractures. The intervertebral disc (IVD) plays an important role in the mechanical behavior of vertebral motion segments. Comparisons between normal and degenerative IVD motion segments following cement augmentation have yet to be reported. A microstructural finite element model of a degenerative IVD motion segment was constructed from micro-CT images. Microdamage within the vertebral body trabecular structure was used to simulate a slightly (I = 83.5% of intact stiffness), moderately (II = 57.8% of intact stiffness), and severely (III = 16.0% of intact stiffness) damaged motion segment. Six variable geometry single-segment cement repair strategies (models A-F) were studied at each damage level (I-III). IVD and bone stresses, and motion segment stiffness, were compared with the intact and baseline damage models (untreated), as well as, previous findings using normal IVD models with the same repair strategies. Overall, small differences were observed in motion segment stiffness and average stresses between the degenerative and normal disc repair models. We did however observe a reduction in endplate bulge and a redistribution in the microstructural tissue level stresses across both endplates and in the treated segment following early stage IVD degeneration. The cement augmentation strategy placing bone cement along the periphery of the vertebra (model E) proved to be the most advantageous in treating the degenerative IVD models by showing larger reductions in the average bone stresses (vertebral and endplate) as compared to the normal IVD models. Furthermore, only this repair strategy, and the complete cement fill strategy (model F), were able to restore the slightly damaged (I) motion segment stiffness above pre-damaged (intact) levels. Early stage IVD degeneration does not have an appreciable effect in motion segment stiffness and average stresses in the treated and adjacent-level segments following vertebroplasty and kyphoplasty. Placing bone cement in the periphery of the damaged vertebra in a degenerative IVD motion segment, minimizes load transfer, and may reduce the likelihood of adjacent-level fractures.

show abstract

Section: Discussionsupporting

confidence: 92%

Section: Introductionmentioning

confidence: 74%

Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

2008

View full text Add to dashboard Cite

show abstract

“…Similar to the diminished neutral zone properties seen with decreasing glycosaminoglycan content in this study, human discs become more hypermobile with early degeneration. 12,13,45 In a cadaver study, Brown et al 12 observed an initial decrease in motion segment stiffness with degeneration, followed by an increase (but not to nondegenerate levels) with further degeneration. Stiffness was quantified by distraction techniques in a loading range of 11 to 30% of maximum applied load (200 N), which may be representative of the neutral zone stiffness of the current study.…”

Section: Discussionmentioning

confidence: 98%

“…[7][8][9][10][11] Mechanical alterations due to degeneration have been noted within each tissue region of the disc as well as in the elastic and viscoelastic response of the entire bone-disc-bone motion segment. [12][13][14][15][16][17][18] However, the quantitative relationships between altered biochemistry and mechanics remain rather unclear, as it is difficult to isolate the multiple biochemical changes occurring in human degeneration.…”

Section: Introductionmentioning

confidence: 99%

Nucleus pulposus glycosaminoglycan content is correlated with axial mechanics in rat lumbar motion segments

et al. 2006

View full text Add to dashboard Cite

The unique biochemical composition and structure of the intervertebral disc allow it to support load, permit motion, and dissipate energy. With degeneration, both the biochemical composition and mechanical behavior of the disc are drastically altered, yet quantitative relationships between the biochemical changes and overall motion segment mechanics are lacking. The objective of this study was to determine the contribution of nucleus pulposus glycosaminoglycan content, which decreases with degeneration, to mechanical function of a rat lumbar spine motion segment in axial loading. Motion segments were treated with varying doses of Chondroitinase-ABC (to degrade glycosaminoglycans) and loaded in axial cyclic compression-tension, followed by compressive creep. Nucleus glycosaminoglycan content was significantly correlated ( p < 0.05) with neutral zone mechanical behavior, which occurs in low load transition between tension and compression (stiffness: r ¼ 0.59; displacement: r ¼ À0.59), and with creep behavior (viscous parameter h 1 : r ¼ 0.34; short time constant t 1 : r ¼ 0.46). These results indicate that moderate decreases in nucleus glycosaminoglycan content consistent with early human degeneration affect overall mechanical function of the disc. These decreases may expose the disc to altered internal stress and strain patterns, thus contributing through mechanical or biological mechanisms to the degenerative cascade. ß

show abstract

“…14 Furthermore, a number of coexisting morphologies have been identified, including traction spurs, 6,40 facet joint hypertrophy, and osteophytic formation. 7 The estimated prevalence of structural LSI reported in the literature ranges from 12% of patients attending physical therapy for nonspecific LBP 1 to 57% of patients with LBP who are suspected of having structural LSI. 23 The differential diagnosis of LBP subgroups, such as structural LSI, is considered vital for more effective manSearch strategy: 1.…”

Section: T T Conclusionmentioning

confidence: 99%

Clinical Tests to Diagnose Lumbar Segmental Instability: A Systematic Review

Alqarni¹,

Schneiders²,

Hendrick³

2011

J Orthop Sports Phys Ther

View full text Add to dashboard Cite

Measurement of Cadaver Lumbar Spine Motion Segment Stiffness

Abstract: The observed results follow an accepted hypothesis of motion segment instability associated with disc degeneration.

Cited by 61 publications

References 14 publications

Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

Nucleus pulposus glycosaminoglycan content is correlated with axial mechanics in rat lumbar motion segments

Clinical Tests to Diagnose Lumbar Segmental Instability: A Systematic Review

Contact Info

Product

Resources

About