RESUMO
Using radiographically demonstrated joint narrowing as an index of joint damage, a reduced incidence of osteophyte size and number as a measure of osteoarthritic change in the PIP and knee joints of patients with RA as compared to DJD has been demonstrated. The possible pathogenetic factors discussed include reduced joint use in RA, increased resilience of juxta-articular bone associated with osteoporosis in RA and the possibility that products of inflammation in the RA joint act locally or via juxta-articular vascular mechanisms to inhibit the secondary changes of DJD. Further study of the possible pathogenic mechanisms including the roles of joint stress, juxta-articular osteoporosis, and possible effects of the inflammatory reaction of the rheumatoid joint on intra-articular structures and juxta-articular vascular phenomena are needed.
