Estimation of shear load sharing in moderately degenerated human lumbar spine
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Estimation of shear load sharing in moderately degenerated human lumbar spine. / Skrzypiec, Daniel M; Bishop, Nicholas E; Klein, Anke; Püschel, Klaus; Morlock, Michael M; Huber, Gerd.
in: J BIOMECH, Jahrgang 46, Nr. 4, 22.02.2013, S. 651-7.Publikationen: SCORING: Beitrag in Fachzeitschrift/Zeitung › SCORING: Zeitschriftenaufsatz › Forschung › Begutachtung
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TY - JOUR
T1 - Estimation of shear load sharing in moderately degenerated human lumbar spine
AU - Skrzypiec, Daniel M
AU - Bishop, Nicholas E
AU - Klein, Anke
AU - Püschel, Klaus
AU - Morlock, Michael M
AU - Huber, Gerd
N1 - Copyright © 2012 Elsevier Ltd. All rights reserved.
PY - 2013/2/22
Y1 - 2013/2/22
N2 - Shear load sharing between intervertebral discs and apophyseal joints was investigated experimentally in human lumbar motion segments with moderately degenerated intervertebral discs. 'Motion-Segments' (21-42 years, n=6) and 'Disc-Segments' (22-42 years, n=6) were subjected to shear in 0° flexion, using a modified materials testing machine, while immersed in a Ringer bath at 37°C. Initially, two cycles of anterior and posterior shear loading up to 200N (50N/s) were applied, to evaluate stiffnesses in both directions. Specimens were then exposed to 15mm of anterior displacement at a rate of 0.5mm/s. A physiological compressive load of 500N was applied throughout. The initial 5mm of the load-displacement curves were approximated with 6th order polynomials for evaluation of the mean behaviour in each group. 'Disc-Segments' were 66% (p=0.002) and 43% (p=0.026) less stiff than 'Motion-Segments' for anterior and posterior shear directions, respectively. 'Disc-Segments' exhibited 44% lower peak shear load (p=0.015) than 'Motion-Segments'. All specimens in the 'Disc-Segments' group showed damage either at the interface between the endplates and the disc. The intervertebral disc contributes 38% to initial anterior shear load-bearing, increasing to 66% at 5mm displacement. Some over-estimation of disc load-bearing might have been caused by the comparison of segments from different levels. The apophyseal joints make a substantial contribution (65-55%) to anterior shear load-bearing over the initial 2mm of shear displacement but this decreases with increasing shear displacement.
AB - Shear load sharing between intervertebral discs and apophyseal joints was investigated experimentally in human lumbar motion segments with moderately degenerated intervertebral discs. 'Motion-Segments' (21-42 years, n=6) and 'Disc-Segments' (22-42 years, n=6) were subjected to shear in 0° flexion, using a modified materials testing machine, while immersed in a Ringer bath at 37°C. Initially, two cycles of anterior and posterior shear loading up to 200N (50N/s) were applied, to evaluate stiffnesses in both directions. Specimens were then exposed to 15mm of anterior displacement at a rate of 0.5mm/s. A physiological compressive load of 500N was applied throughout. The initial 5mm of the load-displacement curves were approximated with 6th order polynomials for evaluation of the mean behaviour in each group. 'Disc-Segments' were 66% (p=0.002) and 43% (p=0.026) less stiff than 'Motion-Segments' for anterior and posterior shear directions, respectively. 'Disc-Segments' exhibited 44% lower peak shear load (p=0.015) than 'Motion-Segments'. All specimens in the 'Disc-Segments' group showed damage either at the interface between the endplates and the disc. The intervertebral disc contributes 38% to initial anterior shear load-bearing, increasing to 66% at 5mm displacement. Some over-estimation of disc load-bearing might have been caused by the comparison of segments from different levels. The apophyseal joints make a substantial contribution (65-55%) to anterior shear load-bearing over the initial 2mm of shear displacement but this decreases with increasing shear displacement.
KW - Adult
KW - Biomechanical Phenomena
KW - Humans
KW - Intervertebral Disc Degeneration
KW - Lumbar Vertebrae
KW - Male
KW - Shear Strength
KW - Spondylolysis
KW - Stress, Mechanical
KW - Weight-Bearing
KW - Young Adult
U2 - 10.1016/j.jbiomech.2012.11.050
DO - 10.1016/j.jbiomech.2012.11.050
M3 - SCORING: Journal article
C2 - 23312826
VL - 46
SP - 651
EP - 657
JO - J BIOMECH
JF - J BIOMECH
SN - 0021-9290
IS - 4
ER -