A Novel Four-Dimensional Ultrasound Approach to Investigate the Relationship Between Ligament Behaviour and Thumb Osteoarthritis Onset
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.