OR9: THE ROLE OF MRI IN UNDERSTANDING KNEE OSTEOARTHRITIS

Abstract

Osteoarthritis (OA) is a major public health problem. Plain radiography, which mainly depicts joint-space narrowing and osteophytes, is useful for defining OA, but has weak associations with symptoms, limited sensitivity to change, as well as poor prediction of cartilage loss and the need for joint replacement. MRI, with standard techniques such as fat-saturated, T1-weighted, spoiled gradient echo sequences and T2-weighted, proton-density-weighted fast-spin echo sequences, has been utilized to directly assess knee structural alterations, such as cartilage volume, cartilage defects, subchondral bone changes and meniscal lesions. MRI factors (cartilage defects, bone marrow lesions, meniscal pathology and bone area) as well as clinical risk factors (age, sex, obesity, smoking and muscle strength) can identify subjects at risk of faster cartilage loss. We hypothesize that a combination of genetic factors interacting with environmental factors might establish a cascade of joint changes from subchondral bone expansion to other structural changes, and ultimately, but not inevitably, lead to OA. MRI has, therefore, been invaluable in improving our understanding of early changes in the knee joint.