Development of bone marrow lesions is associated with adverse effects on knee cartilage while resolution is associated with improvement - a potential target for prevention of knee osteoarthritis: a longitudinal study

Introduction: To examine the relationship between development or resolution of bone marrow lesions (BMLs) and knee cartilage properties in a 2 year prospective study of asymptomatic middle-aged adults. Methods: 271 adults recruited from the Melbourne Collaborative Cohort Study, underwent a magnetic resonance imaging scan (MRI) of their dominant knee at baseline and again approximately 2 years later. Cartilage volume, cartilage defects and BMLs were determined at both time points. Results: Among 234 subjects free of BMLs at baseline, 33 developed BMLs over 2 years. The incidence of BMLs was associated with progression of tibiofemoral cartilage defects (OR 2.63 (95% Cl 0.93, 7.44), P = 0.07 for medial compartment; OR 3.13 (95% Cl 1.01, 9.68), P = 0.048 for lateral compartment). Among 37 subjects with BMLs at baseline, 17 resolved. Resolution of BMLs was associated with reduced annual loss of medial tibial cartilage volume (regression coefficient-35.9 (95% Cl -65, -6.82), P = 0.02) and a trend for reduced progression of medial tibiofemoral cartilage defects (OR 0.2 (95% Cl 0.04, 1.09), P = 0.06). Conclusions: In this cohort study of asymptomatic middle-aged adults the development of new BMLs was associated with progressive knee cartilage pathology while resolution of BMLs prevalent at baseline was associated with reduced progression of cartilage pathology. Further work examining the relationship between changes and BML and cartilage may provide another important target for the prevention of knee osteoarthritis.