Relationship between magnetic resonance imaging lesions and knee symptoms in early knee osteoarthritis: A cross-sectional Japanese population study

Abstract

Background: The prevalence of minute structural abnormalities in early knee osteoarthritis (KOA) and their association with knee symptoms remains unclear. We investigated the prevalence of abnormalities detected by magnetic resonance imaging (MRI) and their relation to knee symptoms in women without radiographic evidence of KOA.Methods: This cross-sectional cohort study in a Japanese population included 261 women without radiographic evidence of KOA, which was defined as a Kellgren‒Lawrence grade < 2. All participants underwent T2-weighted fat-suppressed MRI of their right knee. Structural abnormalities (cartilage damage, bone marrow lesions [BMLs], subchondral cysts, bone attrition, osteophytes, meniscal lesions, and synovitis) were scored according to the Whole-Organ MRI Scoring method. Knee symptoms were evaluated by the Knee injury and Osteoarthritis and Outcome Score (KOOS). Participants were divided into early KOA and non-KOA groups based on early KOA classification criteria. Logistic regression analysis was performed to evaluate the relationship between MRI abnormalities and knee symptoms.Results: Cartilage damage were the most common abnormality (53%), followed by osteophytes (43%), and BMLs (33%). The prevalence of BMLs (47%), meniscal lesions (26%), and synovitis (37%) was higher in early KOA than in non-KOA. On logistic regression analysis, synovitis (odds ratio [OR] = 1.901, P = 0.013) and meniscal lesions (OR = 1.410, P = 0.045) were positively associated with the presence of early KOA.Conclusions: The prevalence of BMLs, meniscal lesions, and synovitis was higher in symptomatic knees. Synovitis was most strongly associated with knee pain and might be a therapeutic target in patients with early KOA.