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.