Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Master of Engineering Science

Program

Biomedical Engineering

Supervisor

Ferreira, Louis

Abstract

This thesis investigates the accuracy and precision of digital volume correlation measurements derived from micro-computed tomography imagery of interfaces in the upper extremity of clinical relevance, namely, the implant-cement-bone interface of glenoid implants used in total shoulder arthroplasties and the implant-bone interface of shoulder hemiarthroplasties. The works within derive relationships between measurement accuracy and precision and parameters of practical interest such as image quality and measurement spatial resolution. It also analyzes the effects of micro-computed tomography image artifact-inducing materials on the accuracy and precision of digital volume correlation-based measurements and the spatial relationship between distance between the artifacting material and the magnitude of change in accuracy and precision. Finally, it also contains an in-vitro model of the peripheral glenoid peg-cement-bone interface which is subsequently analyzed through digital volume correlation; the relationship between peg/bone region and strain magnitude is elucidated.

Summary for Lay Audience

Shoulder osteoarthritis can be a debilitating disease that afflicts two-thirds of individuals older than 65. Current surgical treatments of shoulder osteoarthritis include partial and total shoulder replacements. The implants and/or bone in these shoulder replacement procedures face longevity challenges post-surgery when compared to other joint replacement procedures such as hip replacements or knee replacements, and typically require revision surgery much sooner than is desirable. In order to analyze the manner of failure of these implants, imaging techniques such as high-resolution CT imagery can be used to investigate simulated models of these critical surgical procedures. High-resolution CT imagery can be captured of the bone, implant and implant fixation in both a relaxed state and a state that reflects what the shoulder experiences while under load. These images can then be compared to one another in order to determine the deformation of the bone, the implant fixation, and the implant itself. This measurement technique, known as digital volume correlation, can be used to analyze a variety of clinically relevant problems in the shoulder post-shoulder replacement. However, the magnitude of measurement error associated with digital volume correlation measurements in this application are not well understood and must be first quantified prior to investigating the aforementioned clinical problems. This thesis investigates the accuracy and precision of digital volume correlation measurements in the context of certain shoulder implants and bone configurations in order to prepare for future models which leverage digital volume correlation to study these shoulder implants. It also conducts an analysis of a specific location of one of these shoulder implants which is of potential interest in terms of explaining the early failure of these implant systems. This thesis finds that the accuracy and precision of digital volume correlation measurements are sufficient to investigate the aforementioned clinical problems. The model analysed in this thesis also reinforces the suggestion that the specific location investigated in the shoulder implant is of high interest, and could be a reason for the early failure of these implants.

Creative Commons License

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

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