Corticosteroid injections may not be the best long-term solution for tennis elbow (lateral epicondylitis), even though they may ease the pain in the short term.
According to a meta-analysis of 41 high-quality randomized trials the researchers found that in the first 4 weeks corticosteroid injection had a large effect on pain reduction compared to no treatment, but by week 26, patients who had a corticosteroid injection reported more pain than those who had no intervention, used NSAIDs, physical therapy, and other treatments.
The study also found that repeated corticosteroid injections actually resulted in poorer long-term pain results than just one injection.

