Early diagnosis and management of rheumatoid arthritis (RA) have improved the outcome of patients. In the last decade, musculoskeletal Ultrasonography (MSUS) had demonstrated its superiority over clinical examination in detecting synovitis in RA. We conducted this present study in order to assess the added value of MSUS in diagnosing early RA.
A cross-sectional study was conducted, including one hundred patients diagnosed RA based on the physician's opinion and presenting with inflammatory arthralgia or swollen joints for more than 6 weeks and less than 2 years. Patients underwent clinical, laboratory, and radiographic examination. MSUS was performed by a radiologist blinded to clinical findings assessing 22 joints of hands. A US ACR/EULAR 2010 score was calculated by replacing the swollen joints of hands with those expressing synovitis in Greyscale US. Agreement between clinical and US ACR/EULAR score was assessed.
Among the 2200 joints scanned by the US, synovitis was detected in 81% of patients, an intra-articular effusion in 36% patients, and PD signals in 51% of patients. Flexor tenosynovitis was present in 55% of patients and extensor tenosynovitis in 59% of patients. Synovitis and PD signals were more often detected in wrists. PD mode was found to be correlated with CRP results (r=0,302, p=0,023). The MSUS assessment has demonstrated synovitis on 71% (N=22) patients who were free of swollen joints on clinical examination. Through 13 patients expressing monoarthritis at clinical examination, 69% (N=9) patients were reclassified with oligo or polyarthritis. By adding US data, a further 13 patients accomplished the ACR/EULAR score. A good level of agreement was found between clinical and US ACR/EULAR criteria (k=0,684, p=0,001).
MSUS is an inexpensive and accessible examination tool, which should be considered in patients in the onset of an inflammatory rheumatic disease in order to benefit of the window of opportunity and reach remission.