What is the relationship between osteoarthritis and osteoporosis?

Several epidemiological studies have shown a lower incidence and prevalence of hip fractures in people with osteoarthritis (OA) and vice versa which has led to numerous studies examining the association between OA and osteoporosis more generally. There is felt to be an inverse relationship between these two diseases and the evidence for and against this association is discussed. The evidence for an association with osteoporosis is stronger for large joint OA than hand OA or primary generalized OA. A number of possible mechanisms for this association are discussed such as genetic factors, common risk factors, role of subchondral bone in cartilage damage and growth factors. The incidence and prevalence of one disease in the presence of the other is discussed. Despite the inverse relationship seen in some studies, there is currently no evidence that treatment of one disease can have a detrimental effect on the other.