To assess the magnetic resonance imaging (MRI) and ultrasound (US) changes in the wrist of patients with rheumatoid arthritis (RA) 4 weeks after an US guided intraarticular (IA) injection.
Contrast enhanced MRI and US-Doppler were performed at baseline and 4 weeks after IA injection of either 40 mg methylprednisolone (n = 12) or 25 mg etanercept (n = 13) in 25 patients with RA taking disease modifying antirheumatic drugs with a therapy-resistant wrist joint. All injections were US guided.
There was an improvement in swollen target joint score (p < 0.001), tender target joint score (p < 0.002), and physician visual analog scale score (p < 0.001) after 4 weeks. Baseline MRI synovitis score was mean 5.08 (range 3-9) and was unchanged at followup in the whole group (p = 0.52) and between treatment groups (p = 0.43). MRI edema score (mean 4.46, range 0-29) in the total group was unchanged after 4 weeks (p = 0.13), whereas MRI erosion score increased in the total group from baseline, 17.88 (range 7-40), to 4 weeks, 18.25 (range 7-40) (p < 0.001). Neither US-Doppler color fraction (0.07) nor Resistive Index (RI) (p = 0.36) changed from baseline to 4 week followup.
In contrast to the clinical evaluation, imaging measures of relevance for the estimation of inflammation, US-Doppler, US RI, MRI synovitis, and bone-marrow edema did not change 4 weeks after a single IA injection of either methylprednisolone or etanercept in the wrist. Within the same period, erosive progression in some patients suggested that joints with active disease may deteriorate within as little as 1 month, and that this development is not arrested by 1 injection. Given the small sample size of our study further studies are required to confirm our results.