Arthritis of the Knee Joint in Rheumatoid Arthritis - Evaluation of Treatment Response by Ultrasound in Daily Clinical Practice.

BACKGROUND: Rheumatoid arthritis (RA) commonly involves the knee joint in up to 30% of patients. Musculoskeletal ultrasound enables the skilled clinician to easily assess disease activity.

OBJECTIVE: To evaluate the sensitivity to change of the sonography score of large joints in Rheumatology (SOLAR) for different treatments of knee arthritis in RA.

METHOD: Joints were assessed by ultrasound at 4 visits. Laboratory, immunological and clinical parameters were recorded.

RESULTS: 225 RA patients were analyzed. The DAS 28 in the subgroup receiving systemic steroids was significantly higher (p < 0.001) than in patients treated with intraarticular glucocorticosteroids (GCs) at T0, comparing the values from T0 to T3 the same appeared (p=0.003). Concerning the acute GC treatment regimens, the gray scale ultrasound (GSUS) sum score was found to be significantly higher in patients receiving intraarticular GCs versus no GCs (p=0,035), as well as in patients receiving systemic versus intraarticular GCs (p=0.001). Regarding the differences from T0 and T3, similar to the baseline analysis, a high GSUS sum score was significantly associated with intraarticular GCs, a low to no GC administration (p=0.035), while a high GSUS sum score was significantly linked to intraarticular GCs, rather than systemic GCs (p=0.008).

CONCLUSION: SOLAR score is sensitive to change in knee arthritis. Intraarticular GC administration is performed in patients with high GSUS scores. Systemic administration of GC is linked to high disease activity (DAS28) rather than GSUS or power Doppler ultrasound (PDUS) results.