To evaluate the prevalence of bone marrow lesions (BML) and their association with pain severity in a population-based cohort of symptomatic early knee osteoarthritis (OA).
Subjects with knee pain (n = 255), age 40-79 years, were evaluated by radiograph and magnetic resonance imaging (MRI) and classified into OA stages: no OA (NOA), preradiographic OA (PROA), and radiographic OA (ROA). BML were graded 0-3 (none, mild, moderate, severe) in 6 regions and defined as (1) BMLsum = the sum of 6 scores; and (2) BMLmax = the worst score at any region. Pain was assessed by the Western Ontario and McMaster Universities OA Index (WOMAC). Linear regression analysis was completed to assess the association of Total WOMAC Pain (primary outcome) versus BMLsum or BMLmax. Secondary outcomes were WOMAC Pain on Walking and WOMAC Pain on Climbing Stairs. All analyses were adjusted for age, sex, body mass index, OA stage, joint effusion, and meniscal damage.
BML were present in 11% of NOA, 38% of PROA, and 71% of ROA subjects (p