Structural damage in rheumatoid arthritis: comparison between tendon damage evaluated by ultrasound and radiographic damage

Objective. To compare structural damage assessed by conventional radiography and tendon damage assessed by musculoskeletal US (MSUS) at wrist and ankle in RA patients. Methods. We evaluated 72 consecutive patients [56 (77.8%) females] with RA. The MSUS evaluation consisted in a B-mode examination of bilateral extensor carpi ulnaris and tibialis posterior tendons. Tendon damage was defined and scored according to OMERACT. A total score for the tendon damage score (TDS) was calculated by summing the grades for each tendon. For the radiographic evaluations we used the van der Heijde score; a total radiographic score (RTS) was calculated by summing a bone erosion score (ERS) and a joint space narrowing score (JSNS). Results. We evaluated 288 tendons. The mean (s.d.) of TDS was 2.3 (1.8). Fifty-four (75%) patients presented tendon damage of at least one tendon. From all evaluated tendons, 134 (46.5%) had no tendon damage, 146 (50.7%) had grade 1 and 8 (2.8%) had grade 2 tendon damage. The mean (s.d.) for RTS was 91.4 (97), for ERS was 47.3 (61.9) and for JSNS was 44.1 (37.2). We found a significant correlation between disease duration and both TDS and RTS (r = 0.413 and r = 0.560, respectively; P < 0.0001). We found a good significant correlation between TDS and all variables of radiographic structural damage (RTS, r = 0.65; ERS, r = 0.637; JSNS, r = 0.618; P < 0.001). Conclusion. The MSUS assessment of only four tendons can be an additional feasible method to assess structural damage in RA patients.