Electronic Thesis and Dissertation Repository

Thesis Format

Integrated Article

Degree

Master of Science

Program

Medical Biophysics

Collaborative Specialization

Musculoskeletal Health Research

Supervisor

Lalone, Emily A.

2nd Supervisor

Fenster, Aaron

Affiliation

Robarts Research Institute

Co-Supervisor

Abstract

First carpometacarpal osteoarthritis (CMC-1 OA) is a debilitating disease with no cure. Ligament laxity is thought to precede OA onset, but its role in CMC-1 OA remains understudied. This thesis aims to describe the development of a four-dimensional ultrasound (4D US) device that can be used to visualize the ligaments of the thumb and assess its clinical utility in measuring ligament length dynamically to characterize ligament laxity. It also explores differences in dynamic ligament length between patients with CMC-1 OA and healthy subjects to understand whether there is a relationship between changes in ligament morphology and CMC-1 OA onset.

Chapter 2 describes the development of the 4D US device. The device’s clinical utility was evaluated by acquiring 4D US and 4D CT images of thumb abduction from patients with CMC-1 OA and registering these images to each other to geometrically validate the 4D US device’s ability to detect bony landmarks. Ligament length measurements conducted by two raters showed excellent intra-rater and good inter-rater reliability. This chapter demonstrated that the 4D US device is a reliable tool for measuring ligament length during thumb motion.

Chapter 3 describes the use of the 4D US device on patients with CMC-1 OA and healthy volunteers to assess whether there is a difference in ligament length between the two groups. This study demonstrated that patients with CMC-1 OA had longer ligament lengths compared to the healthy cohort, suggesting a potential relationship between changes in ligament morphology and disease onset.

Summary for Lay Audience

Osteoarthritis (OA) frequently affects the joint at the base of the thumb, especially in older women. Risk factors include age, female sex, joint injury, and genetic predisposition. As there is no cure for OA in the base of the thumb, research focuses on understanding the changes in the joint that influence the onset of the disease to develop preventative measures that can delay the progression of the disease. The thumb joint is supported by an envelope of ligaments, and changes to these ligaments can cause the joint to become unstable, placing it at risk for OA. This pattern has been seen in patients with knee OA, prompting investigations into whether similar patterns exist between changes in ligament integrity and OA onset in the basal thumb joint.

Traditional imaging techniques used to diagnose OA, like radiography and computed tomography, cannot visualize the ligaments of the thumb. However, advances in ultrasonography now allow for high-resolution imaging of hand and wrist anatomy, presenting an opportunity to develop ultrasound devices to identify changes to the ligaments of the thumb that influence the development of OA in the basal thumb joint. This thesis explores the creation of a novel four-dimensional ultrasound (4D US) imaging device to visualize the ligaments of the thumb during motion. This thesis aims to use this device to identify if there are changes in the length of one of the ligaments of the thumb during motion and investigate whether there are differences in ligament length between healthy individuals and patients with OA. The results of this work show that 4D US is a reliable tool to detect ligament length. Additionally, this work demonstrated that patients with OA in their basal thumb joint have significantly longer ligaments in comparison to healthy subjects, suggesting a potential relationship between changes in ligament length and OA onset.

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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