Open MRI for assessing joint biomechanics – applications for osteoarthritis

Hip osteoarthritis is prevalent, disabling and costly to individuals and the healthcare system. Symptomatic hip osteoarthritis affects 4.2 percent of people over 50, and radiographic degenerative changes are seen in almost 20 percent of the same population. In many patients, total hip arthroplasty is used to relieve pain and improve function. Though effective in improving a patient’s quality of life, joint replacements will eventually fail and require revision surgeries that have a higher complication rate and less predictable results. Better strategies to delay or stop the progression of osteoarthritis are needed, which can only be created with a clearer understanding of the disease’s etiology.

While there is strong evidence that structural changes around the hip are major etiological factors in the development of osteoarthritis, it is not clear how to protect hips from the disease. Anatomical abnormalities such as cam-type femoroacetabular impingement (a deformity of the hip bones) may account for 90 percent of hip osteoarthritis cases. However, it is not clear why only some people with these deformities get hip osteoarthritis. It is widely assumed that the relationships between activity and deformity size and their effect on joint mechanics are critical. Investigating these relationships has not been possible to date because there have been few well-validated methods for assessing impingement directly in vivo. This project will answer two research questions:

1. Which activities lead to direct cam impingement at the hip in patients with FAI deformities?
2. How is this impingement influenced by deformity size?

To answer these questions, we will use gait analysis to measure hip movements and mechanics in symptomatic and healthy subjects for a range of activities associated with hip pain. These measurements will be used to develop subject-specific numerical models predicting direct impingement for each participant. Model predictions of direct impingement will be validated by scanning participants using an established protocol in UBC’s upright open MRI scanner.

We have developed a knowledge translation strategy for this project with the Arthritis Patient Advisory Board; they will post the project summary on their website as well as profile the research findings on social media. Results will be published in both clinically- and research-oriented journals and at conferences for both clinicians and scientists.