Association between quantitative lower limb arterial calcification and bilateral severe knee osteoarthritis.

OBJECTIVES: To investigate whether lower limb arterial calcification (LLAC) quantified using computed tomography (CT) was a risk factor for bilateral severe knee osteoarthritis (OA). METHODS: This cross-sectional study included patients who were scheduled for surgical treatment of primary varus knee OA. Knee OA was evaluated using the Kellgren-Lawrence (KL) classification, KL grades 3 and 4 were defined as severe OA. The LLAC score in the bilateral whole leg CT was quantitatively measured and categorized into low or high groups based on the median value. A modified Poisson regression model was used to examine the relationship between the categorized LLAC score and the presence of bilateral severe knee OA with adjustment for possible confounders. RESULTS: Of a total of 252 patients examined, multivariable modified Poisson regression analysis showed a significant association between higher LLAC score and the presence of bilateral severe knee OA (adjusted risk ratio = 1.28; 95% confidence interval [CI], 1.12-1.48; p < .001). A substantial interaction was observed between male sex and high LLAC (p for interaction = .03). CONCLUSION: LLAC was associated with bilateral severe knee OA, and the LLAC score may be a useful measurement to identify patients at risk of bilateral severe knee OA.