HISTOMORPHOMETRY OF PERIARTICULAR BONE IN RHEUMATOID-ARTHRITIS

Periarticular osteoporosis is a common feature of rheumatoid arthritis . However, the cellular basis and the aetiology of periarticular bone loss have not been established. We studied periarticular bone samples obtained from metatarsal resections (n = 18) and total knee arthroplas ties (n = 9) by histomorphometry. Autopsy material (n = 10) and patien ts with osteoarthrosis (n = 11) served as controls. Histomorphometrica lly, there was reduced trabecular bone volume and increased resorption surfaces in rheumatoid arthritis patients in most of the measured are as. The indices of bone turnover were most markedly increased in the v icinity of inflammatory cells and rheumatoid granulation tissue. Trabe cular bone volume and the degree of inflammation as measured by the er ythrocyte sedimentation rate (ESR) had a negative correlation. In addi tion, an elevated ESR was associated with increased osteoid parameters in periarticular bone. We conclude that periarticular bone loss in rh eumatoid arthritiis due to increased bone resorption. Local inflammato ry mediators might account for the increased bone turnover.