Efficacy and predictive factors of response to intra-articular corticosteroids in knee osteoarthritis

In knee osteoarthritis (KOA), synovial inflammation is linked with pain, swelling and structural abnormalities. Intra-articular corticosteroids (IACS) have been considered for pain relief in subjects who are non-responders to standard therapy. However, the results vary across different studies. This review aims to determine efficacy of IACS in KOA by review of the existing data. In several randomized controlled trials (RCTs), meta-analyses and uncontrolled studies a single IACS resulted in pain relief from 1 to a few weeks. In a few studies repeated IACS every three months provided a longer duration of pain relief and functional improvement in a proportion of patients. Baseline synovitis was predictor of treatment response in some but not all studies. Based upon the existing data, IACS provides a short-term pain relief in a proportion of patients. Given, anti-inflammatory properties of IACS, it is likely to be more effective in subgroups of KOA who display inflammatory phenotype.