Juxtaarticular bone loss in experimental inflammatory arthritis

Abstract

The osteopenia associated with experimental inflammatory arthritis was studied by a histomorphometric method that exphasized net changes in bone composition. Juxtaarticular trabecular bone volume and turnover were studied in the carrageenan injection model of inflammatory arthritis of the mature rabbit knee. Trabecular bone volume was studied by histomorphometry of the femoral condyles and confirmed by photodensitometry on standard macroradiographs. Osteogenesis was studied by imaging of calcein fluorochrome-labeled newly formed bone in undecalcified histological sections. A significant net loss of cancellous bone (approximately 20%) occurred over 49 days in both the medial and the lateral femoral condyle in the arthritis group compared with normal controls. Total osteogenesis was increased fourfold and it was calculated that an even greater increase in total bone resorption was responsible for the negative bone balance. There is evidence that the periarticular bone loss of human rheumatoid arthritis is also associated with increased bone turnover. Quantitative studies of the kinetics of bone remodeling in inflammatory arthritis will provide the basis for therapeutic attempts to prevent or reverse arthritis-induced bone loss. Fracture risk in inflammatory arthritis may be increased not only by osteopenia, but additionally by the presence of a large proportion of newly formed (and presumably less mineralized) bone.

Arthritis not immobilization causes bone loss in the carrageenan injection model of inflammatory arthritis

“…In this group, the amount of labeled newly formed bone was three times greater than in the control group; however, the net bone volume was neither increased nor decreased compared with the values for the controls. Although there was no gain in total bone present, the increase in osteogenesis was compatible with an increase in bone resorption (calculated to be 4-fold [1,2]). Evidence for increased turnover in the group with arthritis was observed even though calcein was administered for a short time, early in the course of disease (days 22-36 instead of 22-49, as previously done).…”

Physical bone changes in carragheenin-induced arthritis evaluated by quantitative computed tomography

“…Recently, Bogoch et al [6] reported a 20% net loss ofjuxta-articular bone from mature rabbits with chronic unilateral carragheenin arthritis of the knee compared with a control group without arthritis. Increased bone turnover was primarily responsible for the bone loss.…”

“…These substances have been shown to stimulate bone resorption [11,29,45] and may play such a role in carragheenin arthritis [6], since it is believed that the inflammatory process is initiated by the release of lysosomal enzymes and prostaglandins [8]. However, the bone loss in rheumatoid patients may be further accentuated by steroid administration and loss of activity [47].…”

Celecoxib prevents juxta-articular osteopenia and growth plate destruction adjacent to inflamed joints in rats with collagen-induced arthritis

“…Previously, Bogoch et al 19 reported the occurrence of juxta-articular bone loss in rabbits with experimental infl ammatory arthritis. Hanyu et al 25 concluded that the cause of juxta-articular osteopenia in CIA rats was a signifi cant increase of osteoclasts along with a decrease in the rate of bone formation based on their histomorphomet- Fig.…”

“…Therefore, we investigated the effect of the selective COX-2 inhibitor celecoxib on juxta-articular osteopenia and growth plate destruction in rats with collagen-induced arthritis (CIA), which are commonly used as a model of infl ammatory arthritis like RA and develop juxta-articular osteopenia 19 as well as early closure of the juxta-articular growth plates. 20…”