Subchondral bone and osteoarthritis

Purpose of review Increasing evidence shows that bone is a key factor in the development of osteoarthritis. This article reviews the latest results of basic and clinical research on the role of the subchondral bone in osteoarthritis. Recent findings Early changes in the subchondral bone can predict subsequent symptoms or disease structural progression. New tools may help clinicians to stratify different osteoarthritis phenotypes with regard to bone remodeling status. Summary The involvement of bone in osteoarthritis has long been thought to be secondary to cartilage damage as an adaptation of the joint. Recent clinical studies with MRI have demonstrated that bone changes could be observed in early stages of the disease, even preceding cartilage lesions. Moreover, there is clear evidence of an association between subchondral bone mineral density and osteoarthritis. The level of bone remodeling plays a critical role under mechanical loading conditions as demonstrated by consistent experimental studies. Yet new clinical biomarkers are being developed to assess the bone phenotype of osteoarthritic patients. This stratification strategy is likely to better identify groups of patients who would benefit from bone-acting drugs to decrease disease progression and improve pain and disability.