Abstract
OBJECTIVES: To investigate the association between meniscal pathology and incident or enlarging bone marrow lesions (BML) in knee osteoarthritis. METHODS: The authors studied subjects from the Multicenter Osteoarthritis Study aged 50-79 years either with knee osteoarthritis or at high risk of the disease. Baseline and 30-months magnetic resonance images of knees (n=1344) were scored for subchondral BML. Outcome was defined as an increase in BML score in either the tibial or femoral condyle in medial and lateral compartments, respectively. The authors defined meniscal pathology at baseline as the presence of either meniscal lesions or meniscal extrusion. The risk of an increase in BML score in relation to meniscal status in the same compartment was estimated using a log linear regression model adjusted for age, sex, body mass index, physical activity level and mechanical axis. In secondary analyses the investigators stratified by ipsilateral tibiofemoral cartilage status at baseline and compartments with pre-existing BML. RESULTS: The adjusted relative risk of incident or enlarging BML ranged from 1.8; 95% CI 1.3 to 2.3 for mild medial meniscal pathology to 5.0; 95% CI 3.2 to 7.7 for major lateral meniscal pathology (using no meniscal pathology in the same compartment as reference). Stratification by cartilage or BML status at baseline had essentially no effect on these estimates. CONCLUSIONS: Knee compartments with meniscal pathology have a substantially increased risk of incident or enlarging subchondral BML over 30 months. Higher relative risks were seen in those with more severe and with lateral meniscal pathology.