An update on the pathophysiology of osteoarthritis

Osteoarthritis (OA) is one of the most common forms of arthritis. There is accumulating evidence to suggest that OA is an inflammatory disease of the entire synovial joint and has multiple phenotypes. This presents the OA research community with new challenges and opportunities. The main challenge is to understand the root cause of the disease and identify differences and similarities between OA phenotypes. The key opportunity is the possibility of developing personalized and individualized prevention and treatment strategies for OA patients with different phenotypes of the disease. Indeed, it has been suggested that this is the era of ‘personalized prevention’ for OA. The aim of this mini-review paper is to focus on the pathophysiological aspects of OA development and progression, review the current concepts and discuss the future of personalized medicine for OA. The PubMed/MEDLINE bibliographic database was searched using the keywords ‘pathophysiology’ and ‘osteoarthritis’. The PubMed/MEDLINE search yielded more than 12,000 relevant papers. A selection of these papers is reviewed here. There has been slow but steady progress in our understanding of the pathophysiology of OA over the last two decades. However, large gaps remain in our knowledge of OA pathogenesis and this impacts negatively on patients and drug development pipeline. In the absence of new pharmaceutical agents and disease modifying osteoarthritis drugs (DMOADs) it is clear that lifestyle modification and physical activity are important and may delay the need for surgical intervention.