ABSTRACT
Osteoarthritis or “osteoarthrosis”: Which term is more appropriate? Classically, osteoarthritis (OA), unlike rheumatoid arthritis (RA), is defined as an inherently non-inflammatory disorder of movable joints characterized by deterioration of articular cartilage and the formation of new bone at the joint surfaces and margins (Hough, 1993). In contrast to RA, the synovial fluid in OA typically contains few neutrophils (< 3,
000/mm3), and, except for advanced disease, the synovium does not exhibit significant cellular proliferation or infiltration by inflammatory leukocytes. The molecular pathogenesis of OA is increasingly understood by the elucidation of events within the articular cartilage. For example, altered dynamic equilibrium between matrix synthesis and degradation by human chondrocytes has recently been implicated as having a primary role in the degeneration of articular cartilage resulting in OA (Goldring, 1993; Pelletier et al., 1991, 1996). This includes upregulation of catabolic activities, such as secretion of degradative proteases, and/or downregulation of anabolic activities such as collagen and proteoglycan synthesis.
