Three RCTs were identified (n=260, range 46 to 144): one double-blind and two single-blind. Quality scores for the three trials were 8, 10 and 19.
The authors reported that all trials showed a statistically significant improvement in mean CMS after ESWT when compared to placebo at six months (24.4, 32 and 30.7).
The highest-quality study (n=144) showed a significantly greater improvement in mean CMS for the high-energy ESWT group versus the low ESWT energy group six months after treatment (MD -16.0, 95% CI -22.9 to -10.8), the high-energy group versus the sham group (MD -24.4, 95% CI -31.0 to -17.8) and the low-energy group versus the sham group (MD -8.4, 95% CI -15.4 to -1.4).
The lowest-quality study (n=70) showed a significant improvement in the mean CMS in the (high) ESWT group (mean CMS 71) compared to the sham group (mean CMS 50) at the end of treatment (MD 21, p<0.001). The difference remained significant after six months, but there was a 66% loss to follow-up at six months in the sham group.
The third study (n=46) showed a significant difference (p<0.05) in mean CMS between the (high) ESWT and sham groups six weeks after treatment (74.3 versus 56.2), at 12 weeks (82.8 versus 57.3) and at six months (85.0 versus 54.3) and 12 months after treatment (88.0 versus 56.8).
Adverse events were reported for petechiae, bleeding, haematoma, erythema and initial pain.