Objectives: The etiopathogenesis of bone marrow lesions (BMLs), a key imaging feature of knee osteoarthritis (OA), remains unclear. This study aimed to evaluate the relationship between mechanical loading, as indicated by the external knee adduction moment (KAM) during walking, and BMLs in people with medial knee OA.
Methods: Peak KAM and KAM impulse were measured during walking and BMLs were assessed from knee MRI in 91 individuals with medial knee OA. Logistic regression analyses were performed with presence/absence of medial tibial or medial femoral BMLs as the outcome and either peak KAM or KAM impulse as the independent variable. Analyses were also adjusted for age, gender, BMI, alignment and walking speed.
Results: Medial tibial BMLs were found in 64% of knees and medial femoral BMLs in 60%. In adjusted analyses, peak KAM was significantly related to medial tibial (OR 2.3; 95%CI 1.07-4.7), but not medial femoral BMLs (OR 1.85; 95%CI 0.93-3.7). KAM impulse was significantly related to both medial tibial (OR 9.4; 95%CI 1.53-57.2) and medial femoral (OR 14.4; 95%CI 2.3-89.8) BMLs.
Conclusions: The findings support the hypothesis that greater mechanical loading of the medial compartment plays a role in the pathogenesis of BMLs in medial tibiofemoral OA.