Clinical efficacy of local injection therapies for lateral epicondylitis: A systematic review and network meta-analysis

Background: We aimed to compare the efficacy of local injection therapies for lateral epicondylitis in a Bayesian framework. Methods: We searched the Embase, PubMed, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, and ProQuest, for randomized controlled trials published from inception to February 2021 in any languages. The injection therapies included corticosteroids (CSs), autologous blood (AB), botulinum toxin (BT), and platelet-rich plasma (PRP). Placebo was the reference group for comparison. The study outcomes were pain, function, and strength, at 1, 3 and 6 months after injection. Results: Thirty-one trials were finally included in this network meta-analysis, comprising 1,948 patients. In the first month of treatment, CS and BT were more efficacious than placebo in terms of pain reduction, and CS was superior to BT. In the same follow-up time, CS was also superior to placebo in terms of functional improvement. In the third month of treatment, BT was the only intervention that was more efficient than placebo in pain relief. With regard to functional improvement, none of the treatments significantly had a higher effectiveness than placebo in the same period. Moreover, no therapies were found to be more efficient than placebo in the sixth month of treatment in terms of any study outcomes. In addition, we did not identify an intervention superior to placebo regarding strength improvement outcome in any times of follow-up. Conclusions: CSs and BT are efficient in improving clinical outcomes of lateral epicondylitis in the short term. Also, the efficacy of CSs seems to be greater than BT. On the other hand, AB and PRP were not significantly more efficient than placebo in any times of follow-up.