OBB-0002

Section 1 - Basic information about you and your application:

Title of research project
Changes in the 3D Morphology of the Cervical Intervertebral Foramen During Dynamic Loading: A Possible Source for Post-Operative Pain after Anterior Cervical Diskectomy and Fusion?

Project summary

This project aims to develop understanding of how changes to the 3D anatomy of the Intervertebral Foramen are impacted on by dynamic loading of sections of the cervical spine. Results from this experiment will be discussed in relation to both the stimulation of nociceptive fibres in the nerve root and in the dysfunction of the nerve root itself and how it relates to morbidity after spinal surgery.

This project will form part of a larger study into the pathogenesis of pain and neurological dysfunction as a result from Cervical Surgery, relating to the impact of the significant anatomical changes in adjacent segment height as reported previously. Finally these experimental results will be correlated to the experience of patients from clinical and library-based studies to relate how anatomical changes may result in the over-arching clinical picture of post-operative morbidity.

Type of project
Research

Type of research
Laboratory

Specialty/Area:
Anatomy / Spinal Surgery

Start date
11/06/2023

End date
12/31/2023

Section 2 - Purpose of the research and originality

Aims / Objectives:

This study aims to examine the 3D morphology of the intervertebral foramen on axial, lordotic, shearing and rotational loading in order to discuss the possible implications for the stimulation and compression of nerve root fibres after changes in adjacent segment height due to ACDF Surgery.

Background to investigation:

Anterior Cervical Discectomy and Fusion (ACDF) is indicated in several degenerative conditions of the intervertebral discs. Post-operative pain is frequently reported amongst patients, however the pathogenesis of this is unclear (1). Recent Biomechanical studies have shown there is a significant change in adjacent segment height after ACDF surgery (2) which could be a route by which nociceptive fibres are stimulated. The exact biomechanics of this stimulation are unknown and may be due to the compression of the nerve root via reduction in diameter of the foramen or through direct compression on vertebral bodies and intervertebral discs. By understanding the mechanical pathogenesis of post-operative pain, one may be able to reduce most-operative morbidity through predictive operation planning, accounting for risk factors and correlating this to the mechanisms that may induce pain.

 

1. Lee Y, Issa TZ, Lambrechts MJ, Brush PL, Toci GR, Reddy YC, Fras SI, Mangan JJ, Canseco JA, Kurd M, Rihn JA, Kaye ID, Hilibrand AS, Vaccaro AR, Kepler CK, Schroeder GD. Comparison of Postoperative Opioid Use After Anterior Cervical Diskectomy and Fusion or Posterior Cervical Fusion. J Am Acad Orthop Surg. 2023 Sep 1;31(17):e665-e674. doi: 10.5435/JAAOS-D-23-00003. Epub 2023 Apr 28. PMID: 37126845.
2. Diffley T, Whittaker D, Matejova M, Dragoneva W, Parson S, Baliga S; There are Significant Changes in Adjacent Segment Height After Anterior Cervical Discectomy and Fusion: A source of postoperative pain?, Global Spine Congress 2024 [Abstract], Bangkok, Thailand, May15th-18th 2024.

Section 3 - Plan of investigation

Plan of investigation:

This study will use human Cervical spine specimens removed from cadavers in the University of Aberdeen Anatomy Lab. These will then be dissected and cleaned, retaining structures surrounding the intervertebral foramen and nerve root. These specimens will then be placed in a jig / vice that is capable of providing Axial, Lordotic, shear and rotational loading. Then by providing compression in these planes in 0.1mm intervals the 3D morphology of the intervertebral foramen will be mapped using a Revware Microscribe IL+ Which has a maximum resolution of 1 micrometer. These maps will be translated into Computer-Aided Design software and using Rhino / Solidworks platforms the 3D dimensions of the intervertebral foramen will be measured using the integrated software to analyse how the foramen changes with varying degrees of compression.

The relationship between the dynamic loading and intervertebral foramen will be determined using Compression-geometry graphs with measurements of Diameter, Eccentricity, surface area, superior and inferior component alignment and other geometric parameters using the CAD-generated models. Multivariable statistical analysis will further investigate the relationships between loading protocols and geometric parameters, determining the how the geometry of the intervertebral foramen is related to the elastic properties of the intervertebral disc and surrounding tissue structures, advancing discussion on arthroplasty and fusion implant engineering.

Section 4 - Research impact and benefits

Research impact and benefits:

This funding will allow me to continue and advance research conducted as part of a Research Scholarship Last Summer. There has been interesting results which I believe are important to orthopaedic surgery, particularly spine surgery, and will be able to aid implant design, intra-operative technique and physiotherapy to reduce the morbidity of patients after ACDF Procedures. There are several other things I would also like to study following on from this project which will take a lot of time in the lab. Naturally as an undergraduate student i need a way to support myself and by having some funding to cover the necessities means i can fully commit and delve deep into my research ensuring the best possible quality for clinical applications.

 

Whilst this project is not part of my intercalated degree honours project, it is going on whilst i am studying for a BSc in Anatomy. I would like to reiterate this project in no way contributes to my grade and is entirely done in my free time which as a result is very limited. I love doing research and would love to continue pursuing this research question as i have become fascinated with this topic and want to pursue it as far as i feasibly can. Following research topics that i intend to investigate will be:

• The Distribution of Nerve Fibres in the Vertebral Bodies and their Relationship to Load Distribution Analyzed by Piezoelectric Interferometry (Experimental)
• Distribution of Nociceptive Fibres in the Intervertebral Discs (Experimental – exact methodology to be determined)
• The Epidemiology and Characteristics of Post-Operative Morbidity after Anterior Cervical Discectomy and Fusion: Results from the British Spine Register (Clinical Study – Permissions currently being applied for)
• Reported Morbidity in Patients Partaking in Randomised Control Trials of ACDF Surgeries – A Systematic Review and Meta-Analysis (Systematic Review – Ongoing)

This study forms part of a much bigger clinical picture that i have been working on, whilst i am currently unfunded having some funding will allow me to really dedicate my time to focus on my research and gather robust data, from which further research questions and methods can be developed on. I have prior research publications in clinical studies and have conducted numerous research projects before however this project is new in that it is not only surgical but also has histological, radiological and biomechanical aspects to its overall methodology. The varied methodology of each chapter ensures a holistic and clinically relevant approach to this research question and a multi-faceted analysis into the understanding of post-operative morbidity after spinal surgery.

Section 5 - Strength of individual and achievements to aid facilitate the project?

Name:
Mr. Thomas Diffley

Institution:
University of Aberdeen / Anatomy Department, University of Aberdeen

Year of study / grade / job title:
4th Year Medical Student

Graduation date:
07/02/2026

Are you undertaking this project as part of an intercalated degree?
No

Does your institution offer an intercalated degree option?
Yes

Role
Principle Researcher

Supervisor name
Simon Parson

Supervisor job title
Professor of Anatomy

Supervisor address
Anatomy Department, University of Aberdeen Suttie Centre for Teaching and Learning, Foresterhill Road Aberdeen, Aberdeen CIty AB25 2ZR United Kingdom

Applicant reference
See Email for Contact