Background Anterior chest wall (ACW) joints can be involved during the course of Rheumatoid arthritis (RA) and ankylosing spondylitis (AS), however, its clinical implications appear to be underestimated by the rheumatology community.

Objectives To determine the prevelance and types of subclinical ultrasonographic changes in the ACW joints in RA and AS patients and their association with the chest expansion.

Methods The study was conducted on 132 sternoclavicular joints (SCJ) and 66 manibrusternal joints (MSJ) in 66 subjects (22 AS, 22 RA, and 22 control). Ultrasound (US) assessments were performed to detect synovitis, erosions, ankylosis, osteophytes, or doppler signals. Chest expansion was measured. In RA group, Disease Activity Score (DAS28) and Health Assesment Questionare Disability Index (HAQDI) were recorded. In AS group, Ankylosing Spondylitis Disease Activity Score (ASDAS), Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Bath Ankylosing Spondylitis Functional Index (BASFI) were recorded.

Results US detected subclinical changes of ACW joints in (74.2%) of RA, (77.3%) of AS, and (21.2%) of control groups. There was a highly significant difference between total US changes in RA (74.2%) and control (21.2%) (p<0.001) and also between AS (77.3%) and control (21.2%) (p<0.001). Non of our control had neither erosions nor ankylosing in MSJ. MSJ ankylosing was signficantly higher in AS (77.3%) than RA (18.2%) (p<0.001). MSJ ankylosing was highly associated with limited chest expansion in both RA and AS (P<0.001). All patients (100%) in both groups (RA and AS) with MSJ ankylosing by US had limited chest expansion. In RA group, ultrasonographic changes were found to be higher with smoking, longer disease duration and high DAS28. In AS group, ultrasonographic changes were found to be higher with older age, male sex, smoking, longer disease duration and high BASDAI and BASFI.

Conclusions US detected subclinical changes of ACW joints in a high percentage of RA and AS patients. No erosions or ankylosing in MSJ were Found in the healthy individuals. MSJ ankylosing is more in AS than RA. Relatively, ankylosing of MSJ by US is highly associated with limited chest expansion in RA and AS. Up to the best of our knowledge, our study was the first study that detected subclinical changes of ACW joints in RA and AS by US.

References

1. Rodríguez-Henríquez P, Solano C, Peña A, Leόn-Hernández S,Hernández-Díaz C, Gutiérrez M, et al. Sternoclavicular jointinvolvement in rheumatoid arthritis: clinical and ultrasoundfindings of a neglected joint. Arthritis Care Res 2013;65:1177–82.

2. Frank Verhoeven, Xavier Guillot, Marie Godfrin-Valnet, Clément Prati, et al: Ultrasonographic Evaluation of the Anterior Chest Wall in Spondyloarthritis: A Prospective and Controlled Study; J Rheumatol 2015;42;87–92.

References

Disclosure of Interest None declared