Background Spinal mobility is a major health issue of patients with axial spondyloarthritis (axSpA), especially in ankylosing spondylitis (AS) while non-radiographic axSpA (nr-axSpA) has been less well studied in this regard. The available tools such as the BASMI and, indirectly, also the BASFI have limitations in exactly quantifying spinal mobility.
Objectives To evaluate the performance of a newly developed electronic tool to measure spinal mobility.
Methods Consecutive patients with axSpA, mechanical back pain and healthy controls were examined by the Epionics spine device (ESp), a novel electronic system, which measures the range of motion (ROM) for spinal mobility using non-invasive angle sensor strips in 12 evenly spaced locations along the spine. ESp has been shown to reliably measure the ROM for all domains of spinal mobility (flexion, extension, rotation and combinations). Physical examinations (BASMI), questionnaires (BASFI) and a recently proposed tool to assess function (ASPI, 1) were performed in parallel. The assessors were unaware of the results of the other tests. The time to use the device was measured. Statistical comparisons between groups were performed with the Mann-Whitney-U-test.
Results A total of 65 patients with axSpA (38 (58%) with AS and 27 (42%) with nr-axSpa), 48 patients with mechanical back pain (mBP) and 20 healthy controls (HC) were included in this prospective study. The BASFI and BASMI values were generally higher in patients with AS (4.1±2.3 and 2.7±2.3) vs. nr-axSpA (3.8±1.9 and 1.2±1.0), mBP (4.0±2.4 and 1.3±1.1) and HC (0.5±0.7 and 0.6±0.8). Using ESp, the measured range of ROM AS patients performed worse in all aspects (Table). The mean duration of performance of ESp was 12±3 minutes.
Conclusions The Epionics spine device had good construct, content and face validity in this first study, which prospectively compared patients with axSpA, mechanical back pain and healthy volunteers. It will be interesting to study its correlation to single BASMI and BASFI items and to learn whether it provides higher sensitivity to change as compared to conventional assessments of spinal mobility and function.
van Weely S. et al, J Rheumatol 2015
Acknowledgements The study is supported by Epionics Medical GmbH. Epionics expenses for hardware. Support and training was funded by AbbVie in context of another study. The authors determined study design, conduct of the study and the content of the publication. No payments were made to the authors for writing this manuscript.
Disclosure of Interest None declared