Osteoarthritis (OA) is a disease of the whole joint. It can be defined in a number of ways-clinical, radiological and on MRI scanning [1,2]. These definitions often give highly variable estimates of prevalence. These is no doubt, however, that OA is incredibly common over the age of 50 and has an increasing prevalence due to the ageing of the population particularly in western countries. Joint replacement is an effective therapy but is extremely costly and the current upwards trajectory is unsustainable [3]. Other therapies such as weight loss, paracetamol, NSAIDs and narcotics are modestly effective (at best) [4] and often come with risks as well as benefits. Thus, there is an urgent need for alternative therapies.

In the last 20 years, it has become increasingly apparent that OA does not have a single pathogenic pathway and that cartilage loss is a final common pathway for many different pathological changes both within and outside the joint. These have been summarised previously (Table 1) [5]. The identification of these different pathways have led to efforts aimed at developing precision medicine in osteoarthritis on the theoretical grounds that one may achieve greater efficacy if therapy is matched to pathology rather than one size fits all. For example, bone targeted therapy may be most likely to work for bone marrow lesions. This review will summarise the recent developments in therapy categorised by target (summarised in Table 2).