Magnetic resonance imaging evidence of tendinopathy in early rheumatoid arthritis predicts tendon rupture at six years.

OBJECTIVE

To determine whether magnetic resonance imaging (MRI) evidence of tendinopathy in early rheumatoid arthritis (RA) could be used to predict the course of tendon involvement in later disease and specifically the risk of tendon rupture.

METHODS

The occurrence, pattern, and progression of tendinopathy were studied prospectively over 6 years in a cohort of patients who had presented with RA. Of 42 patients enrolled, full MRI and clinical data were available for 31 at 6 years. MRI scans of the dominant wrist were scored for tendinopathy by 2 radiologists using a validated system. These data were compared with MRI synovitis, erosion scores, and disease activity measures. Prognostic factors for tendon inflammation and rupture were sought.

RESULTS

Thirty-four patients (81%) had MRI evidence of tendinopathy at baseline, falling to 59% at 1 year and 68% at 6 years. The most commonly affected site was the extensor carpi ulnaris. MRI tendinopathy and synovitis scores were correlated at baseline (r = 0.37, P = 0.01) and 1 year (r = 0.45, P = 0.003) but not at 6 years (r = 0.11, P = 0.5). The strongest predictor of the 6-year tendinopathy score was the 1-year tendinopathy score (R(2) = 0.36, P = 0.0003 [beta = 1.28, SE = 0.31]). In 4 patients, extensor tendon rupture had occurred by 6 years. Their baseline and 1-year tendinopathy scores were higher than in the nonrupture group (medians 2.8 versus 1.0 [P = 0.04] and 4.3 versus 0.8 [P = 0.03], respectively), as were their Health Assessment Questionnaire scores (1.33 versus 0.54 [P = 0.02], 1.18 versus 0.25 [P = 0.03], and 0.98 versus 0.37 [P = 0.01] at 0, 1, and 6 years, respectively). For the group as a whole, the baseline tendinopathy score was predictive of rupture at 6 years (odds ratio [OR] 1.52, 95% confidence interval [95% CI] 1.02-2.32, P = 0.03), as was the 1-year score (OR 1.57, 95% CI 1.03-2.04, P = 0.02).

CONCLUSION

MRI can be used to quantify tendinopathy at the wrist in RA patients. High scores in early disease were predictive of tendon rupture in a small group of patients, but further studies are required to determine whether this has clinical relevance.