The role of synovitis in osteoarthritis

Abstract

Osteoarthritis (OA) is the most common form of arthritis worldwide yet there is still a lack of effective treatments for this condition. Increasingly, attention has turned to the role of the synovium in OA as it is now recognized, in part from the use of modern imaging techniques, that synovitis is both common and associated with pain. This offers a target for treatment, for both symptom and potential structure modification. In this review we discuss the evidence for histological and imaging-detected synovitis and the current role of antisynovial therapies in OA.

Keywords: histology; magnetic resonance imaging; osteoarthritis; synovitis; ultrasound.

Figure 1.

Schematic representation of key pathological events and potential targets for disease modification in osteoarthritis. Mediators that represent potential therapeutic targets have been identified in both synovial tissue and cartilage. Less well identified are targets derived from bone. BMP, bone morphogenic protein; IL, interleukin; MMP, matrix metalloproteinase; NO, nitric oxide; PA, plasminogen activator; PGE₂, prostaglandin E₃; TGF, transforming growth factor; TIMP, tissue inhibitor of metalloproteinase; TNF, tumour necrosis factor. (Adapted by permission from Macmillan Publishers Ltd: [Nature Clinical Practice Rheumatology] (Abramson et al. 2006), copyright (2006).)