title: Osteoarthritis.
abstract: Osteoarthritis (OA) is the most common joint disorder, is associated with an increasing socioeconomic impact owing to the ageing population and mainly affects the diarthrodial joints. Primary OA results from a combination of risk factors, with increasing age and obesity being the most prominent. The concept of the pathophysiology is still evolving, from being viewed as cartilage-limited to a multifactorial disease that affects the whole joint. An intricate relationship between local and systemic factors modulates its clinical and structural presentations, leading to a common final pathway of joint destruction. Pharmacological treatments are mostly related to relief of symptoms and there is no disease-modifying OA drug (that is, treatment that will reduce symptoms in addition to slowing or stopping the disease progression) yet approved by the regulatory agencies. Identifying phenotypes of patients will enable the detection of the disease in its early stages as well as distinguish individuals who are at higher risk of progression, which in turn could be used to guide clinical decision making and allow more effective and specific therapeutic interventions to be designed. This Primer is an update on the progress made in the field of OA epidemiology, quality of life, pathophysiological mechanisms, diagnosis, screening, prevention and disease management.
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), 900 rue Saint-Denis, Suite R11.412, Montreal, Quebec H2X 0A9, Canada.
authors.forename: Johanne
authors.initials: J
authors.lastname: Martel-Pelletier
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, UK.|NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Barr
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, Victoria, Australia.
authors.forename: Flavia M
authors.initials: FM
authors.lastname: Cicuttini
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Leeds, UK.|NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Conaghan
authors.affiliation: MRC Lifecourse Epidemiology Unit, University of Southampton, Southampton, UK.|NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Oxford, UK.
authors.forename: Cyrus
authors.initials: C
authors.lastname: Cooper
authors.affiliation: The Hospital for Special Surgery (HSS), HSS Research Institute; and Weill Cornell Medical College, New York, New York, USA.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Goldring
authors.affiliation: The Hospital for Special Surgery (HSS), HSS Research Institute; and Weill Cornell Medical College, New York, New York, USA.
authors.forename: Steven R
authors.initials: SR
authors.lastname: Goldring
authors.affiliation: Menzies Institute for Medical Research, University of Tasmania, Hobart, Tasmania, Australia.
authors.forename: Graeme
authors.initials: G
authors.lastname: Jones
authors.affiliation: Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Alfred Hospital, Melbourne, Victoria, Australia.|Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Teichtahl
authors.affiliation: Osteoarthritis Research Unit, University of Montreal Hospital Research Centre (CRCHUM), 900 rue Saint-Denis, Suite R11.412, Montreal, Quebec H2X 0A9, Canada.
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Pelletier
mesh_terms: D018450:Disease Progression; D006801:Humans; D010003:Osteoarthritis / Q000175:diagnosis* / Q000188:drug therapy* / Q000503:physiopathology*; D012307:Risk Factors