Accelerated metacarpal bone mineral density loss is associated with radiographic progressive hand osteoarthritis.

OBJECTIVE: To study the association between metacarpal bone mineral density (BMD) loss and progressive hand osteoarthritis (OA) over 2 years. METHODS: Using the Kellgren-Lawrence (KL) grading scale and the Osteoarthritis Research Society International Atlas, standardised hand radiographs of 181 patients with primary OA at multiple sites (mean age 60 years, 80% women, mean body mass index 27 kg/m(2)) were assessed for hand OA at baseline (KL ≥ 2 in two or more hand joints) and progressive hand OA over 2 years (≥ 1 point increase in total osteophyte and joint space narrowing score in patients with hand OA at baseline). Changes in BMD were measured over 2 years in metacarpals 2-4 by digital x-ray radiogrammetry. Accelerated BMD loss was defined as loss of >3 mg/cm(2)/year. Logistic regression analyses were performed to assess the associations between BMD loss and progressive hand OA. RESULTS: The baseline prevalence of hand OA was 68% and, after 2 years, 32% of these patients had progressive hand OA. Accelerated BMD loss was present in 79% of the patients with progressive hand OA compared with 60% and 57% of the patients with non-progressive hand OA and no hand OA, respectively. BMD loss was independently associated with progressive hand OA compared with non-progressive hand OA with a RR (95% CI) of 2.1 (1.1 to 4.3). CONCLUSION: Accelerated metacarpal BMD loss is associated with progressive hand OA over a period of 2 years; knowledge of common mechanisms may lead to development of therapeutic interventions for hand OA.