Objectives To identify differences in the prevalence of synovitis between palmar and dorsal ultrasound (US) in patients with rheumatoid arthritis (RA). Further to compare US findings with clinical and laboratory parameters.
Methods Ultrasound data of 76 patients with RA, collected in the context of US studies in RA at the rheumatologic Outpatient Clinic of the Charité-University Hospital Berlin, Germany, from 2005 to 2010, have been surveyed. The clinically more affected hand (wrist and finger joints) was assessed by US in gray scale (GSUS) and power Doppler (PDUS). In detail, radiocarpal, ulnocarpal and mediocarpal wrist joints as well as the metacarpophalangeal (MCP) 2-5 and the proximal interphalangeal (PIP) 2-5 joints were examined by GSUS and PDUS from dorsal and from palmar. Overall, the assessment scope covered 836 joints of the whole hand. 61 patients underwent additional US examination of their second to fifth metatarsophalangeal (MTP) joint, hence 244 joints of the foot from dorsal and plantar. GSUS was conducted by using a qualitative and a semiquantitative (grade 0 to 3 for none, mild, moderate and distinct synovitis) score, PDUS by applying a semiquantitative score (0-3) only. Clinical examination and laboratory tests were performed in order to confirm disease activity (DAS 28; CRP, ESR) and serological status (rheumatoid factor (RF), anti-citrullinated protein antibodies[ACPA]). Further, disease duration and current medications have been recorded.
Results We found that sum scores of grades in GSUS and PDUS of the palmar hand (palmar GS resp. PD hand score = pGSHS resp. pPDHS) correlated stronger to DAS28, CRP, ESR and duration of symptoms than sum scores in GSUS resp. PDUS of the dorsal hand (dorsal GS resp. PD hand score = dGSHS resp. dPDHS). Furthermore, GSUS of the palmar and the dorsal hand showed a higher correlation to inflammation markers (CRP, ESR) than power Doppler of the palmar resp. dorsal hand (Table 1). Palmar GSUS of the affected hand detected the highest number of joints with synovitis (≥ °1 in semiquantitative method) with a prevalence of 77.3% in comparison to dorsal GSUS of the hand with a prevalence of 69.6% of positive joints. The difference between the prevalence of palmar resp. dorsal values is significant (Wilcoxon p=0.001). At the forefeet, dorsal GSUS revealed much more synovitis positive joints (prevalence 54.5%) thanplantar GSUS (prevalence 16.0%).
Conclusions Due to the ability to detect more synovitis positive joints and due to slightly higher correlation to inflammatory activity, palmar GSUS appears to be a highly relevant component in the ultrasonographic examination of the wrist and finger joints in RA patients.
Disclosure of Interest L. Vogler: None Declared, S. Ohrndorf Grant/Research support from: Arthromark Research support, J. Messerschmidt: None Declared, B. Reiche: None Declared, G. Burmester: None Declared, M. Backhaus Grant/Research support from: Pfizer Researc support