Bone marrow lesions are related to dynamic knee loading in medial knee osteoarthritis

Objectives: To evaluate the relationship between mechanical loading, as indicated by the external knee adduction moment (KAM) during walking, and BML on MRI in people with medial knee osteoarthritis. Methods: Measures were taken in 91 individuals with medial knee osteoarthritis. Logistic regression analyses were performed with the presence/absence of medial tibial or medial femoral BML as the outcome and either peak KAM or KAM impulse as the independent variable. Analyses were also adjusted for age, gender, body mass index, alignment and walking speed. Results: In adjusted analyses, peak KAM was significantly related to medial tibial (OR 2.3; 95% CI 1.07 to 4.7), but not medial femoral (OR 1.85; 95% CI 0.93 to 3.7) BML. KAM impulse was significantly related to both medial tibial (OR 9.4; 95% CI 1.53 to 57.2) and medial femoral (OR 14.4; 95% CI 2.3 to 89.8) BML. Conclusions: The findings support the hypothesis that greater mechanical loading of the medial compartment plays a role in the pathogenesis of BML in medial tibiofemoral osteoarthritis.