Extracorporeal Shock Wave Therapy Shows Superiority Over Injections for Pain Relief and Grip Strength Recovery in Lateral Epicondylitis: A Systematic Review and Network Meta-analysis

Abstract

Purpose: To examine the efficacy of extracorporeal shock wave therapy (ESWT) and injection therapies by synthesizing direct and indirect evidence for all pairs of competing therapies for lateral epicondylitis.

Methods: PubMed, EMBASE, and Web of Science databases were searched for all appropriate randomized controlled trials (RCTs), assessing the effect of ESWT or injection therapies. The primary outcome was short-term (≤3 months) and medium-term (>3 months but ≤12 months) pain, while the secondary outcomes were grip strength and patient-reported outcome measures. All outcomes were assessed using standardized mean differences (SMDs) with 95% confidence intervals (CIs) and were ranked using surface under the cumulative ranking curve (SUCRA) probabilities to determine a hierarchy of treatments. Sensitivity analysis was performed to eliminate potential therapeutic effects of normal saline (NS) and exclude trials that included patients with acute lateral epicondylitis (LE).

Results: 40 RCTs were included to evaluate ESWT and five different injection therapies, including corticosteroids (CSs), autologous whole blood, platelet-rich plasma (PRP), botulinum toxin A (BoNT-A), and dextrose prolotherapy (DPT). DPT (-.78 [-1.34 to -.21]), ESWT (.57 [-.89 to -.25]), PRP (-.48 [-.85 to -.11]), and BoNT-A (-.43 [-.84 to -.02]) outperformed placebo for short-term pain relief; ESWT (-.44 [-.85 to -.04]) outperformed placebo for medium-term pain relief. DPT was ranked as the most optimal short-term and medium-term pain reliever (SUCRA, 87.3% and 98.6%, respectively). ESWT was ranked as the most optimal short-term and medium-term grip strength recovery (SUCRA; 79.4% and 86.4%, respectively).

Conclusions: DPT and ESWT were the best two treatment options for pain control and ESWT was the best treatment option for grip strength recovery. CSs were not recommended for the treatment of LE. More evidence is required to confirm the superiority in pain control of DPT among all these treatment options on LE.

Level of evidence: Level I, meta-analysis of Level I randomized controlled trials.

Keywords: botulinum toxin A; extracorporeal shock wave therapy; injection therapy; lateral epicondylitis; network meta-analysis; platelet-rich plasma; prolotherapy; tennis elbow.