In recent decades there has been a dramatic change in the treatment approaches for management of rheumatoid arthritis (RA). The introduction of methotrexate and the subsequent development of the biological agents that target tumour necrosis factor (TNF) and/or immune cell activation pathways have dramatically improved patient outcomes. Nevertheless, as additional information becomes available from prospective studies of patients receiving these therapies, there is evidence that a significant number of individuals continue to experience progressive joint damage and functional impairment. 1–6 Based on these observations, there is a need to develop validated assessment tools for identifying patients who are at risk for a poor prognosis and to target this population for more aggressive and/or specific therapies to prevent eventual joint damage. In this and a recent issue of the Annals of Rheumatic Diseases, two independent groups of investigators have utilised the techniques of bone mineral density (BMD) and radiographic analysis to assess bone loss in patients with early RA and to validate the changes in BMD as a predictor of subsequent radiographic evidence of focal marginal joint erosions. 7 8 Both of the studies have exploited the evidence that the RA inflammatory process produces adverse effects on both local articular as well as systemic bone remodelling. 9–13

The skeletal changes can be segregated into distinct patterns on the basis of anatomic site and distribution. These include focal marginal joint erosions (the radiographic hallmark of RA), subchondral bone erosions, periarticular osteoporosis and systemic osteoporosis. These skeletal changes are associated with net bone loss and in all instances are reflective of an imbalance in the activities of the cells that mediate bone resorption and formation.