Objective: There is increasing evidence for the involvement of vascular disease in the pathogenesis of knee osteoarthritis. Popliteal artery wall thickness can be used as a surrogate marker of atherosclerosis. We examined the association between popliteal artery wall thickness and knee cartilage volume in individuals with symptomatic knee osteoarthritis.

Methods: This prospective cohort study analysed 176 participants from a randomised placebo-controlled trial examining the effect of atorvastatin on structural progression in knee osteoarthritis. The participants underwent magnetic resonance imaging (MRI) of the study knee at baseline and two-year follow-up. Popliteal artery wall thickness and tibial cartilage volume were measured from MRI using validated methods. The top quartile of the rate of tibial cartilage volume loss was defined as rapid progression.

Results:At baseline, every 10% increase in popliteal artery wall thickness was associated with 120.8 mm3 (95% CI 5.4-236.2, p= 0.04) lower of medial tibial cartilage volume and 151.9 mm3 (95% CI 12.1-291.7, p= 0.03) lower of lateral tibial cartilage volume. Longitudinally, for every 10% increase in popliteal artery wall thickness, the annual rate of medial tibial cartilage volume loss was increased by 1.14% (95% CI 0.09%-2.20%, p= 0.03) and there was a 2.28-fold (95% CI 1.07-4.83, p= 0.03) risk of rapid progression of medial tibial cartilage loss, adjusted for age, sex, body mass index, tibial bone area, smoking, vigorous physical activity, and intervention group allocation.

Conclusion:The findings support a role for vascular pathology in the progression of knee osteoarthritis. Targeting atherosclerosis has the potential to improve outcomes in knee osteoarthritis.