Abstract
Objective. To evaluate whether features of radiographic hand osteoarthritis (OA) are associated with quantitative magnetic resonance imaging (MRI)-defined knee cartilage thickness, radiographic knee OA, and 1-year structural progression.
Methods. A total of 765 participants in Osteoarthritis Initiative (OAI; 455 women, mean age 62.5 yrs, SD 9.4) obtained hand radiographs (at baseline), knee radiographs (baseline and Year 1), and knee MRI (baseline and Year 1). Hand radiographs were scored for presence of osteophytes and joint space narrowing (JSN). Knee radiographs were scored according to the Kellgren-Lawrence (KL) scale. Cartilage thickness in the medial and lateral femorotibial compartments was measured quantitatively from coronal FLASHwe images. We examined the cross-sectional and longitudinal associations between features of hand OA (total osteophyte and JSN scores) and knee cartilage thickness, 1-year knee cartilage thinning (above smallest detectable change), presence of knee OA (KL grade ≥ 3), and progression of knee OA (KL change ≥ 1) by linear and logistic regression. Both hand OA features were included in a multivariate model (if p ≤ 0.25) adjusted for age, sex, and body mass index (BMI).
Results. Hand JSN was associated with reduced knee cartilage thickness (ß = −0.02, 95% CI −0.03, −0.01) in the medial femorotibial compartment, while hand osteophytes were associated with the presence of radiographic knee OA (OR 1.10, 95% CI 1.03–1.18; multivariate models) with both hand OA features as independent variables adjusted for age, sex, and BMI). Radiographic features of hand OA were not associated with 1-year cartilage thinning or radiographic knee OA progression.
Conclusion. Our results support a systemic OA susceptibility and possibly different mechanisms for osteophyte formation and cartilage thinning.
Footnotes
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Supported by the National Institutes of Health, a branch of the Department of Health and Human Services, contracts N01-AR-2-2258; N01-AR-2-2259; N01-AR-2-2260; N01-AR-2-2261; N01-AR-2-2262; and by Pfizer Inc., Novartis Pharmaceuticals Corporation, Merck Research Laboratories, and GlaxoSmithKline. Image analysis was supported by Pfizer Inc., Eli Lilly & Co., Merck Serono SA, GlaxoSmithKline, Wyeth Research, Centocor, and Novartis Pharma AG, the OAI coordinating centre at UCSF (CA), and Chondrometrics GmbH. I.K. Haugen is supported by grants from the South-Eastern Norway Regional Health Authority.
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M. Englund is supported by the Swedish Research Council and the Faculty of Medicine, Lund University, Sweden. F. Eckstein provides consulting services to MerckSerono, Novartis, and Sanofi Aventis.
- Accepted for publication August 24, 2011.