Structure and strength of the distal radius in female patients with rheumatoid arthritis: A case-control study

Abstract

The purpose of this work was to investigate the volumetric bone mineral density (vBMD), bone microstructure, and mechanical indices of the distal radius in female patients with rheumatoid arthritis (RA). We report a cross-sectional study of 66 middle-aged female RA patients and 66 age-matched healthy females. Areal BMD (aBMD) of the hip, lumbar spine, and distal radius was measured by dual-energy X-ray absorptiometry (DXA). High-resolution peripheral quantitative computed tomography (HR-pQCT) was performed at the distal radius, yielding vBMD, bone microstructure, and mechanical indices. Cortical and trabecular vBMD were 3.5% and 10.7% lower, respectively, in RA patients than controls, despite comparable aBMD. Trabecular microstructural indices were -5.7% to -23.1% inferior, respectively, in RA patients compared to controls, with significant differences in trabecular bone volume fraction, separation, inhomogeneity, and structural model index. Cortical porosity volume and percentage were 128% and 93% higher, respectively, in RA patients, with stress being distributed more unevenly. Fourteen RA patients had exaggerated periosteal bone apposition primarily affecting the ulnovolar aspect of the distal radius. These particular patients were more likely to have chronic and severe disease and coexisting wrist deformity. The majority of the differences in density and microstructure between RA patients and controls did not depend on menstrual status. Recent exposure to glucocorticoids did not significantly affect bone density and microstructure. HR-pQCT provides new insight into inflammation-associated bone fragility in RA. It detects differences in vBMD, bone microstructure, and mechanical indices that are not captured by DXA. At the distal radius, deterioration in density and microstructure in RA patients involved both cortical and trabecular compartments. Excessive bone resorption appears to affect cortical more than trabecular bone at distal radius, particularly manifested as increased cortical porosity. Ulnovolar periosteal apposition of the distal radius is a feature of chronic, severe RA with wrist deformity. ß

Differences in bone structure between rheumatoid arthritis and psoriatic arthritis patients relative to autoantibody positivity

“…Little is known about cortical bone changes in patients with RA apart from bone erosion and cortical bone loss in the phalangeal bones, as assessed by Dual-energy x-ray absorptiometry 41. Zhu and colleagues reported that Ct.Po is increased in women with compared to those without RA 35. In our study we did not find major differences in cortical density, Ct.Th or Ct.Po among RA[+], RA[−] and PsA subjects, suggesting that cortical bone changes are shared by various different inflammatory joint diseases.…”

“…No study has been performed in PsA and only one study has been carried out in RA patients which focused on a subsegment of RA patients. Zhu and colleagues found that vBMD and BV/TV were decreased and trabecular inhomogeneity was increased in women with RA compared to those without RA 35. Although this study confirmed the notion that RA is associated with trabecular bone loss, the results can hardly be generalised based on the exclusive assessment of women, the lack of information about the autoantibody status and the fact that only a very few patients received biological drug therapy, which is now widely used for the treatment of RA and PsA patients in many countries.…”

Carotid plaque and bone density and microarchitecture in psoriatic arthritis: the correlation with soluble ST2

“…vBMD and microstructure were measured at the distal radius of the non-dominant forearm using HR-pQCT (Scanco Medical AG, Bruettisellen, Switzerland) as described before1539. The participant’s forearm was fixed in a carbon fiber cast, and a dorsal-palmer projection image was obtained to define the tomographic scan region.…”

Cortical thinning and progressive cortical porosity in female patients with systemic lupus erythematosus on long-term glucocorticoids: a 2-year case-control study

“…Trabecular thickness and separation were then derived from BV/TV and trabecular number using standard stereological relations. Our short-term HR-pQCT reproducibility, expressed as RMSCV, ranged from 0.38 to 1.03 % for density measures, from 0.28 to 1.10 % for geometric measures, and from 1.72 to 3.73 % for microstructural measures [22].…”