Utility of Radiofrequency Echographic Multi-spectrometry in Evaluating Bone Health in Patients With Spondylarthritis

Abstract

Introduction: Osteoporosis, a condition characterized by reduced bone strength and increased fracture risk, frequently coexists with spondyloarthritis (SpA), an inflammatory rheumatic disease. Dual-energy X-ray absorptiometry (DXA), the gold standard for diagnosing osteoporosis, faces limitations in SpA patients due to spinal deformities and calcifications. Some studies have shown overestimation of BMD values, especially in individuals with syndesmophytic bridges and coexistent mechanical modifications such as osteophytes and discopathic lesions.

Materials and methods: A cross-sectional study was performed to compare the results of bone mineral density (BMD) lumbar spine evaluations performed with Radiofrequency Echographic Multi-spectrometry (REMS) between a control group and a group of patients recently diagnosed with axial spondyloarthritis (axSpA) who did not follow any specific treatment. All study participants were informed about the objectives, examinations performed, and the use of anonymous data in databases to conduct statistical analyses and publish findings in reference medical scientific journals.

Results: The ratio between male and female participants differed between the study groups. No significant differences were observed between the control and SpA groups, in both female and male subjects, with regard to BMD values. When factoring in the age of the patients, it was observed that the mean age of the control group was 55.53 years, while that of the SpA group was 36.96 years. This suggests that the BMD values of younger SpA patients were equivalent to those of older individuals in the control group.

Conclusion: REMS is a useful tool for evaluating BMD both in the general population and in SpA patients. Furthermore, the lack of any statistically significant correlation between the control and SpA groups confirms that the rheumatic disease influences lumbar bone mineralization. Also, similar BMD values were observed between the groups, despite significantly different mean ages, supporting the conclusion that bone degradation appears early in the evolution of SpA and can be correctly identified using REMS.

Keywords: bone mineral density; dual x-ray absorptiometry; fragility fracture; radiofrequency echographic multispectrometry; spondylarthritis.

Figure 1. The age distribution of the two study groups (independent sample t-test, p-values<0.001).

Levene test of equality of variance yielded a p<0.001, confirming that there are no equal variances between the study groups. SpA, Spondyloarthritis.

Figure 2. ROC curve describing the relationship between age and vertebral structural modifications found on imagistics in the control group.

Chi² = 347.98, p < 0.001. ROC, receiver operating characteristic.

Figure 3. ROC curve describing the relationship between age and vertebral structural modifications found on imagistics in the SpA group.

Chi² = 2.35, p = 0.125. ROC, receiver operating characteristic; SpA, spondyloarthritis.

Figure 4. MRI T1 acquisition of the lumbar spine from subject "iv-377".

The white arrows point out multiple vertebral modifications such as osteophytes and fatty infiltration of the vertebral plateaus. The black arrows identify an aneurysmal dilation of the abdominal aorta, associating parietal thrombosis. MRI, magnetic resonance imaging.

Figure 5. MRI T1 acquisitions in frontal plane (A) and lateral plane (B) of the lumbar spine in a patient diagnosed with SpA.

The white arrows point at two vertebral corner fatty infiltration modifications, while the black arrows point at the presence of a large hemangioma occupying approximately 90% of the L1 vertebral body. MRI, magnetic resonance imaging; SpA, spondyloarthritis.