ABC of Rheumatology: OSTEOARTHRITISBMJ 1995; 310 doi: https://doi.org/10.1136/bmj.310.6977.457 (Published 18 February 1995) Cite this as: BMJ 1995;310:457
- Adrian Jones,
- Michael Doherty
Osteoarthritis is the commonest condition to affect synovial joints, the single most important cause of locomotor disability, and a major challenge to health care. Previously considered as a degenerative disease that was an inevitable consequence of aging and trauma, osteoarthritis is now viewed as a metabolically dynamic, essentially reparative process that is increasingly amenable to treatment.
There is no generally accepted definition of osteoarthritis, but most would agree that pathologically it is a condition of synovial joints characterised by focal cartilage loss and an accompanying reparative bone response. Defining this in practice is less easy. Current definition of clinical cases hinges on detecting structural changes clinically or in radiographs. For many the plain radiograph remains the best means of assessment, with evidence of cartilage loss (joint space narrowing) and bone response (presence of osteophytes and sclerosis) being the main criteria. This definition, however, excludes joints with early minimal change, ignores tissues other than cartilage and bone, and omits consideration of biological consequences (symptoms and disability). There is often considerable discordance between structural change and clinical outcome; patients with apparent structural catastrophe may have few or no symptoms. Better understanding of the causes of symptoms and disability is currently a key challenge.
Process of osteoarthritis
Observations about osteoarthritis have led to the suggestion that it is an aspect of the inherent repair process of synovial joints:
Osteoarthritis has been present throughout evolution and is ubiquitous in humans and other vertebrates.
Osteoarthritis is not simply the attrition of joint structures but is a metabolically active condition that shows a variable balance between anabolic and catabolic processes—at different stages there is increased activity in all joint tissues (cartilage, bone, synovium, capsule, and muscle)
Osteoarthritis is common but is usually asymptomatic
Occasionally, there is radiographic evidence of osteoarthritic joints “healing.”