# Extracorporeal shockwave therapy versus sham extracorporeal shockwave therapy for chronic Achilles tendinopathy: a meta-analysis of randomized controlled trials

## TL;DR

This study finds that extracorporeal shockwave therapy (ESWT) does not significantly improve chronic Achilles tendinopathy compared to a placebo treatment, though it may help with short-term pain relief in some patients.

## Contribution

The study provides a meta-analysis comparing ESWT and sham ESWT for chronic Achilles tendinopathy, identifying a potential benefit in short-term pain reduction for patients with recent symptoms.

## Key findings

- ESWT did not significantly improve pain or function compared to sham ESWT in chronic Achilles tendinopathy.
- Subgroup analysis suggests ESWT may reduce pain in patients with symptom duration under 12 months.
- Adverse events were slightly higher with ESWT but not statistically significant.

## Abstract

Chronic Achilles tendinopathy is a persistent and debilitating condition. Extracorporeal shockwave therapy (ESWT) is widely used, but its true effectiveness and safety for chronic Achilles tendinopathy remains debated. This study aimed to compare the effectiveness and safety of ESWT and sham ESWT for chronic Achilles tendinopathy.

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, PubMed, EMBASE, Cochrane Library, and Web of Science were systematically searched for randomized controlled trials (RCTs) comparing ESWT with sham ESWT in chronic Achilles tendinopathy. Primary outcomes included pain reduction (change in Visual Analog Scale (ΔVAS), minimal clinically important difference (MCID) 1.1/10) and functional improvement (change in Victorian Institute of Sports Assessment-Achilles (ΔVISA-A), MCID 8/100; change in American Orthopaedic Foot and Ankle Society (ΔAOFAS), MCID 12/100). Secondary outcomes encompassed adverse events. Risk of bias was assessed via Risk of Bias 2 (RoB2). Meta-analysis used RevMan 5.4.1, with weighted mean differences (WMD) and odds ratios (ORs) for continuous and dichotomous outcomes, respectively. Hypothesis-generating subgroup analyses explored ESWT type, tendinopathy classification, and symptom duration.

Eight RCTs (458 participants) were included. No significant differences were observed between ESWT and sham groups in ΔVAS or ΔVISA-A, ΔAOFAS across follow-ups all P > 0.05). Adverse events were higher with ESWT (4.5% vs. 1.2%), though non-significant (P = 0.12). Subgroup analysis found that ESWT led to significant VAS reduction in patients with symptom duration < 12 months at 1-month (WMD: −0.76, P = 0.03) and 3-month (WMD: −1.23, P = 0.001) follow-ups than Sham ESWT.

ESWT showed no clear overall benefits compared to sham ESWT for chronic Achilles tendinopathy, but exploratory analyses hint at possible short-term pain relief for patients with symptoms lasting less than 12 months. More high-quality evidence is needed.