Osteoarthritis

Osteoarthritis (OA) is the most common degenerative joint disorder. In this Primer, Pelletier and colleagues provide an update on the progress made in the field of OA epidemiology, pathophysiological mechanisms, diagnosis, prevention, disease management and quality of life.

Metabolic reprogramming of immune cells and somatic cells alike has a role in perpetuating disease in the joints. In this Review, the authors examine metabolic alterations that occur in the main cells of the joint tissues during osteoarthritis.

Transforming growth factor-β (TGFβ) is a pleiotropic cytokine that is important in the regulation of joint homeostasis and disease. In this Review, the changing role of TGFβ in normal joint homeostasis, ageing and osteoarthritis is discussed.

In this Review, the authors summarize the changes that occur in the biocomposite formed by articular cartilage and bone during the evolution of osteoarthritis (OA). They also discuss how an improved understanding of these changes could be exploited to develop new therapies for patients with OA.

Emerging evidence suggests the nervous system, including the circadian timing system, influences susceptibility to osteoarthritis (OA) via direct and indirect effects. This Review describes the interactions between the brain and the joints in the context of OA, ageing, obesity and inflammation, and outlines therapeutic and research opportunities in this field.

Although changes associated with ageing promote the development of osteoarthritis (OA), ageing and OA are independent processes. In this Review, the authors discuss the mechanisms by which age-related factors contribute to OA through effects on articular cartilage and propose that future improvements in our understanding of these mechanisms will inform new therapies to slow or stop the progression of OA.

Osteoarthritis (OA) is a chronic condition that is associated with pain and disability. In this Review, Roos and Arden consider the strategies that are available for modification of risk factors contributing to the development of knee OA. Interventions for prevention and early care of knee OA could help to avoid joint-replacement surgery.

Osteoarthritis (OA) and rheumatoid arthritis (RA) are disorders of the joints that involve degradation of the extracellular matrix of cartilage, and proteases and inflammatory mediators are common to both conditions. However, different cells are affected in OA (chondrocytes) and RA (synoviocytes), and treating these diseases requires an understanding of their differences as well as their similarities.

Current osteoarthritis therapies cannot sufficiently target cartilage and guarantee a biological response owing to limitations in the delivery methods. This Perspectives article discusses how electrostatic interactions can be utilized to increase drug penetration and retention in cartilage to provide sustained intra-tissue delivery.

Lipopolysaccharide derived from gastrointestinal microbiota contributes to systemic inflammation and obesity. Huang and Kraus propose that lipopolysaccharide is a major risk factor for osteoarthritis (OA), and suggest that therapeutic strategies for the reduction of systemic levels of lipopolysaccharide should be considered for prevention and treatment of OA.

Radiographic joint-space width is the standard structural outcome for trials in knee osteoarthritis (OA), but MRI provides comprehensive 3D insights into the multi-tissue pathology of OA and could provide a superior means of monitoring disease progression and response to treatment. A new study highlights bone as an imaging biomarker.

Although paracetamol is widely used and recommended for the management of pain in osteoarthritis, accumulating data indicate that it lacks efficacy and is associated with severe adverse effects. A new meta-analysis adds further weight to calls for clinical practice and treatment guidelines to be updated to reflect the evidence.

Arthroscopic surgery to remove torn meniscal tissue is a controversial treatment that, together with the meniscal tear itself, is associated with a high risk of developing knee osteoarthritis (OA). But what of surgical approaches to repair or replace the meniscus? Are these procedures justified with respect to the later development of OA?