Grant: Project Grant

Osteoarthritis (OA) is the most common form of arthritis. Hip OA on x-ray occurs in 19.6% of adults over age 50 and 14.3% of people over the age of 60 have hip pain. Femoroacetabular impingement (FAI) is a condition where a bony bump in the hip region leads to pressure on different tissues in the hip. This is thought to be exacerbated by physical activity. FAI can be identified on x-rays. It has been proposed that FAI is the single most common cause of hip OA. Magnetic resonance imaging (MRI) is the only modality that can assess different joint tissues in detail, including cartilage and bone, and can detect early stage OA, often decades before it shows up on x-ray. With novel techniques, such as contrast-enhanced MRI of cartilage, we can see damage in cartilage even earlier. We have previously recruited a randomly selected cohort of 182 people with and without FAI, with and without hip pain. Subjects were evaluated in detail at baseline with questionnaires, including a life-time physical activity questionnaire, x-rays, MRI, contrast-enhanced MRI and blood/urine samples for future biomarker analysis. We propose to reevaluate this cohort 6 years after baseline. The objectives of this study are to determine whether 1) those with FAI, compared to those without, are at increased risk of worsening of cartilage damage and early hip OA on MRI; 2) physical activity is a risk factor for early hip OA on MRI and whether this risk is exacerbated with FAI; 3) biomarkers predict early hip OA. This study is unique. For the first time, in such a well-defined cohort, we will determine the risk of FAI and of physical activity on early hip OA. Our results will be generalizable to the population at large. Understanding the role that these factors play in the development of hip OA over time is a key step in future prevention strategies, to improve treatment of this disabling condition and thereby reduce the burden and health care costs of this disease in Canada and world-wide.