dc.contributor.advisor |
Thambyah, A |
en |
dc.contributor.advisor |
Broom, N |
en |
dc.contributor.author |
Turley, Sean |
en |
dc.date.accessioned |
2017-05-05T02:50:04Z |
en |
dc.date.issued |
2016 |
en |
dc.identifier.uri |
http://hdl.handle.net/2292/32784 |
en |
dc.description.abstract |
The distal end of the third metacarpal bone is among the most highly loaded sites in the equine appendicular skeleton, and a common site of injury and degeneration. The objective of this thesis was to investigate site-specific changes in the microstructure and mechanical properties of the osteochondral tissues of the distal third metacarpal in response to in vivo loading, and how such changes may precede lesion development in the palmar region. Osteochondral tissue changes were evaluated in terms of mechanical and morphological parameters, including in athletically trained horses. Mechanical testing included indentation testing to determine cartilage modulus, and impact testing. Tissue morphology was assessed using bright field microscopy and differential interference contrast microscopy to view thick osteochondral sections in a full hydrated state. Regions of higher in vivo loading were associated with thinner calcified cartilage, reduced cartilage mechanical properties, and greater cement line rugosity and subchondral bone volume fraction. High subchondral bone volume fraction, high cement line rugosity, and reduced cartilage mechanical properties were identified as possible precursors of degenerative change in the articular cartilage of the palmar region. The progression of repetitive overload-induced lesions in the palmar aspect of the third metacarpal of Thoroughbred racehorses was documented from initial microcrack formation through to severe subchondral bone collapse. Extensive levels of microdamage were frequently concealed beneath outwardly intact hyaline cartilage. Notably, fibrous repair tissue was found at the articular surface in cases where subsidence of the subchondral bone had occurred, suggesting a repair response aimed at maintaining articular surface congruity. However, there was some evidence to suggest that this repair tissue was vulnerable to mechanical disruption when exposed to continued loading. This thesis makes a contribution to the literature by: (i) Providing detailed information on site-specific adaptations in osteochondral morphology and mechanical properties in relation to load, including in athletically trained animals; (ii) Identifying osteochondral changes that may predispose towards degeneration; (iii) Documenting the morphological progression of damage accumulation and lesion development in the palmar aspect of racing Thoroughbreds; and (iv) Presenting detailed images of the aforementioned lesions in the full context of the joint tissue complex, spanning from the articular surface to the subchondral bone. |
en |
dc.publisher |
ResearchSpace@Auckland |
en |
dc.relation.ispartof |
PhD Thesis - University of Auckland |
en |
dc.relation.isreferencedby |
UoA99264956914102091 |
en |
dc.rights |
Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated. Previously published items are made available in accordance with the copyright policy of the publisher. |
en |
dc.rights.uri |
https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm |
en |
dc.rights.uri |
http://creativecommons.org/licenses/by-nc-sa/3.0/nz/ |
|
dc.title |
Site-specific effects of loading on the osteochondral tissues of the equine distal metacarpus |
en |
dc.type |
Thesis |
en |
thesis.degree.discipline |
Engineering |
en |
thesis.degree.grantor |
The University of Auckland |
en |
thesis.degree.level |
Doctoral |
en |
thesis.degree.name |
PhD |
en |
dc.rights.holder |
Copyright: The author |
en |
dc.rights.accessrights |
http://purl.org/eprint/accessRights/OpenAccess |
en |
pubs.elements-id |
624407 |
en |
pubs.record-created-at-source-date |
2017-05-05 |
en |
dc.identifier.wikidata |
Q112931761 |
|