Fragility Score in Radiographic Axial Spondyloarthritis Assessed with Radiofrequency Echographic Multi-Spectrometry (REMS)

Axial spondyloarthritis (axSpA) is a chronic inflammatory disease affecting the sacroiliac joints and spine and is associated with an increased risk of fractures due to persistent inflammation, reduced mobility and treatment-related factors. In radiographic axSpA (r-axSpA), assessment of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA) may be limited by structural spinal changes. This cross-sectional study, conducted between March 2024 and June 2025, evaluated skeletal fragility in patients with r-axSpA using Radiofrequency Echographic Multi-Spectrometry (REMS)-derived Fragility Score (FS). Ninety patients with r-axSpA and sex-matched healthy controls underwent clinical assessment and REMS evaluation of lumbar spine and hip BMD, T-scores and spinal FS. Patients with r-axSpA had lower body mass index and higher rates of smoking, prior fractures and inflammatory markers compared with controls, while disease activity reflected a moderate burden. No significant differences in BMD or T-scores were observed between groups. However, FS was significantly higher in patients with r-axSpA (46.6 ± 15.4 vs. 31.2 ± 13.3, p = 0.004), corresponding to a higher fracture risk category, whereas correlations between FS and clinical parameters were not statistically significant. These findings suggest that REMS-derived FS may identify increased skeletal fragility in r-axSpA beyond conventional BMD measurements.