An Investigation Into The Mineral And Mechanical Properties Of The Canine Intervertebral Disc And Its Clinical Implications

Intervertebral disc disease is a very common problem in dogs. The disease causes pain and different degrees of neurological damage which can result in paralysis and leads to the death of many dogs annually. The disease is intimately associated with disc degeneration and calcification, but the precise mechanisms by which these pathological processes are linked remain a mystery. Degeneration of the intervertebral disc occurs in an accelerated way in many dogs, particularly those types known as chondrodystrophic, and involves calcification which has been shown to be associated with disc herniation or extrusion. The process is complex and involves the transformation of collagen fibres, loss of proteoglycans and notochord cells and a reduction in water content; however, how these processes are linked to future disc herniation remains unknown. Most studies to date have focused on imaging changes and histopathology of affected discs, but here we take a novel approach exploring the use of a number of different techniques associated with mineralogy and materials science. We have employed Fourier-Transform Infra- red Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Uniaxial Load Compression (ULC) and immunofluorescence staining in an attempt to gain a greater understanding of the degenerative process and its consequences on the physical properties of the disc. FTIR verified by TEM demonstrated that calcium phosphate exists in an amorphous state within the disc and that the formation of crystalline particles of hydroxyapatite occurs prior to disc extrusion. AFM identified crystalline agglomerates consistent with hydroxyapatite as well as extracellular matrix structures such as individual collagen fibres, in addition to nanomechanical properties such as deformation and adhesion. SEM enabled the identification of regions rich in calcium, phosphorous and oxygen and allowed the visualization of the topographical landscape of the disc. Compression testing generated stress/strain curves facilitating investigation into disc stiffness, and a preliminary identification of Poly (ADP-Ribose) (PAR), a possible molecular marker for calcification, was achieved by immunostaining. Ongoing work in our group is aimed at identifying potential areas of intervention in the degenerative process as well as further characterizing the role of calcification in disc extrusion. Our results have allowed us to generate some testable hypotheses which could ultimately help to unravel the way in which disc degeneration and disease are linked, and lead to novel methods of prevention and treatment.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2025

Author dc:creator

• Rojas Solano, Viviana

Advisor dc:contributor.advisor

• Alves, Lisa

• intervertebral disc
• IVDD
• veterinary neurology

Licence

• https://www.repository.cam.ac.uk/bitstreams/7a5a7ec2-1813-4fc8-a32c-3e1248fcf159/download
• http://purl.org/NET/rdflicense/allrightsreserved

Language dc:language

eng

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.122090

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/390537