Multiscale Mechanical Changes to the Collagenous Structure in the Annulus Fibrosus from Adult Degenerative Disc Disease and Adult Spine Deformity Surgical Patients

Dhiman, Manmeet

Multiscale Mechanical Changes to the Collagenous Structure in the Annulus Fibrosus from Adult Degenerative Disc Disease and Adult Spine Deformity Surgical Patients

dc.contributor.advisor	Duncan, Neil
dc.contributor.author	Dhiman, Manmeet
dc.contributor.committeemember	Swamy, Ganesh
dc.contributor.committeemember	Hart, David
dc.date	2023-11
dc.date.accessioned	2023-07-06T19:26:45Z
dc.date.available	2023-07-06T19:26:45Z
dc.date.issued	2023-06
dc.description.abstract	The annulus fibrosus in patients with degenerative disc disease (degen) and adult spinal deformities, including degenerative spondylolisthesis (dSpondy), isthmic spondylolisthesis (iSpondy), degenerative scoliosis (dScoli), and adolescent idiopathic scoliosis (AIS), often exhibit severely degenerated discs at the time of surgery. These conditions are accompanied by mechanical and structural changes in the annulus fibrosus, which can cause significant pain and affect mobility. In many cases, the patients require surgical intervention. The overarching hypothesis was that surgical patients have mechanical and structural integrity of the annulus fibrosus compared to normal patients. The objective of the study was to quantify the interlamellar mechanics, circumferential tensile mechanics, and collagen damage in samples from these patients. Interlamellar mechanical properties (Peel Stiffness, Peel Strength, and Peel Toughness) were decreased in the surgical patients compared to the normal patients suggesting a loss of integrity of the collagenous interlamellar matrix in surgical patients. Moderate to strong positive correlations between interlamellar properties and Pfirrmann Grade were observed. Circumferential tensile properties (Rate of Change of Tangential Modulus, Linear Elastic Modulus, Yield Stress, and Ultimate Tensile Stress) were decreased in the surgical patients compared to the normal patients suggesting a loss of collagen's mechanical integrity in the circumferential direction. The collagen hybridizing peptide indicated greater average mean fluorescence intensity and average percent positive ROI area in the surgical patients compared to the normal patients suggesting a loss of structural integrity of collagen. In conclusion, the present study demonstrated that compared to normal patients, surgical patients experienced a greater loss of collagen's structural and mechanical integrity in the annulus fibrosus at molecular and tissue scales.
dc.identifier.citation	Dhiman, M. (2023). Multiscale mechanical changes to the collagenous structure in the annulus fibrosus from adult degenerative disc disease and adult spine deformity surgical patients (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/116706
dc.identifier.uri	https://dx.doi.org/10.11575/PRISM/41548
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Annulus Fibrosus
dc.subject	Degenerative Disc Disease
dc.subject	Spine Deformities
dc.subject	Collagen
dc.subject	Biomechanics
dc.subject.classification	Engineering--Biomedical
dc.title	Multiscale Mechanical Changes to the Collagenous Structure in the Annulus Fibrosus from Adult Degenerative Disc Disease and Adult Spine Deformity Surgical Patients
dc.type	master thesis
thesis.degree.discipline	Engineering – Biomedical
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.thesis.accesssetbystudent	I require a thesis withhold – I need to delay the release of my thesis due to a patent application, and other reasons outlined in the link above. I have/will need to submit a thesis withhold application.