The effects of needle damage on annulus fibrosus micromechanics.

2.50
Hdl Handle:
http://hdl.handle.net/11287/620482
Title:
The effects of needle damage on annulus fibrosus micromechanics.
Authors:
Vergari, C.; Mansfield, J. C.; Chan, Daniel; Clarke, Andrew J; Meakin, J.R.; Winlove, P. C.
Abstract:
Needle puncture of the intervertebral disc can initiate a mechanical and biochemical cascade leading to disc degeneration. Puncture's mechanical effects have been shown near the puncture site, mechanical effects should be observed far, relative to needle size, from the puncture site, given the disc-wide damage induced by the stab. The aim of this work was to quantify these far-field effects, and to observe the local structural damage provoked by the needle. Strips of cow tail annulus fibrosus underwent two consecutive mechanical loadings to 5% tensile strain; fifteen samples were punctured in a radial direction with a randomly assigned needle between the two loadings (needle gauges between 19 and 23). Ten samples (control group) were not punctured. During loading, the tissue strains were imaged using second harmonic generation microscopy in a <600×800µm region about 4.4mm from the puncture site. After mechanical testing, the puncture site was imaged in 3D. Puncture had no significant effect on annulus elastic modulus. Imaging showed a modest change in the shearing between fibre bundles however, the linear strain between bundles, intra-bundle shear and linear strain were not significantly affected. At the puncture site, detached lumps of tissue were present. These results suggest that the mechanical effects observed in intact discs are due to the depressurization of the disc, rather than the local damage to the annulus. Needle profiles could be designed, aiming at separating fibre bundles rather than cutting through them, to avoid leaving dying tissue behind.
Citation:
The effects of needle damage on annulus fibrosus micromechanics. 2017, 63:274-282 Acta Biomater
Publisher:
Elsevier
Journal:
Acta biomaterialia
Issue Date:
Nov-2017
URI:
http://hdl.handle.net/11287/620482
DOI:
10.1016/j.actbio.2017.09.015
PubMed ID:
28917706
Additional Links:
https://linkinghub.elsevier.com/retrieve/pii/S1742-7061(17)30578-0
Type:
Journal Article
Language:
en
ISSN:
1878-7568
Appears in Collections:
Exeter Spinal Surgery Unit; 2017 RD&E publications

Full metadata record

DC FieldValue Language
dc.contributor.authorVergari, C.en
dc.contributor.authorMansfield, J. C.en
dc.contributor.authorChan, Danielen
dc.contributor.authorClarke, Andrew Jen
dc.contributor.authorMeakin, J.R.en
dc.contributor.authorWinlove, P. C.en
dc.date.accessioned2017-11-01T16:48:36Z-
dc.date.available2017-11-01T16:48:36Z-
dc.date.issued2017-11-
dc.identifier.citationThe effects of needle damage on annulus fibrosus micromechanics. 2017, 63:274-282 Acta Biomateren
dc.identifier.issn1878-7568-
dc.identifier.pmid28917706-
dc.identifier.doi10.1016/j.actbio.2017.09.015-
dc.identifier.urihttp://hdl.handle.net/11287/620482-
dc.description.abstractNeedle puncture of the intervertebral disc can initiate a mechanical and biochemical cascade leading to disc degeneration. Puncture's mechanical effects have been shown near the puncture site, mechanical effects should be observed far, relative to needle size, from the puncture site, given the disc-wide damage induced by the stab. The aim of this work was to quantify these far-field effects, and to observe the local structural damage provoked by the needle. Strips of cow tail annulus fibrosus underwent two consecutive mechanical loadings to 5% tensile strain; fifteen samples were punctured in a radial direction with a randomly assigned needle between the two loadings (needle gauges between 19 and 23). Ten samples (control group) were not punctured. During loading, the tissue strains were imaged using second harmonic generation microscopy in a <600×800µm region about 4.4mm from the puncture site. After mechanical testing, the puncture site was imaged in 3D. Puncture had no significant effect on annulus elastic modulus. Imaging showed a modest change in the shearing between fibre bundles however, the linear strain between bundles, intra-bundle shear and linear strain were not significantly affected. At the puncture site, detached lumps of tissue were present. These results suggest that the mechanical effects observed in intact discs are due to the depressurization of the disc, rather than the local damage to the annulus. Needle profiles could be designed, aiming at separating fibre bundles rather than cutting through them, to avoid leaving dying tissue behind.en
dc.language.isoenen
dc.publisherElsevieren
dc.relation.urlhttps://linkinghub.elsevier.com/retrieve/pii/S1742-7061(17)30578-0en
dc.rightsArchived with thanks to Acta biomaterialiaen
dc.subjectWessex Classification Subject Headings::Orthopaedicsen
dc.titleThe effects of needle damage on annulus fibrosus micromechanics.en
dc.typeJournal Articleen
dc.identifier.journalActa biomaterialiaen
dc.type.versionPublisheden

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