Proposal for a sonographic classification of target joints in rheumatoid arthritis

The purpose of this study was to classify sonographically the joint damage of target joints in patients with rheumatoid arthritis (RA).

During a 3-year cross-sectional study, standardized arthrosonography of symptomatic target joints was performed in patients with RA. According to those findings, a classification with progressive deterioration of joint alteration in RA was created that grades visible morphological changes of the joint components. Using elbow joints as a subgroup, inter- and intraobserver reliability was calculated.

Examined and included in this study were 1211 joints of 425 patients with RA. The mean disease activity score was 5.2 (range 0.75-7.79). Sonographically visible changes could be classified and divided into six stages. A standardized sonographic evaluation system was developed. In reference to the elbow joint, overall percentages for intra- and interobserver reliability of sonography were 90.8% and 88.8%, respectively.

Sonography is a valuable tool for assessing and classifying joint alteration in RA. Particularly in early stages of joint affection, ultrasound is superior to X-ray in detecting soft tissue changes and minor erosions.