Effects of Extracorporeal Shock Wave Therapy in Patients with Mild-to-Moderate Carpal Tunnel Syndrome: An Updated Systematic Review with Meta-Analysis

Abstract

Background: Carpal tunnel syndrome (CTS) is the most common entrapment syndrome, primarily affecting women between the ages of 40 and 70, and conservative treatments are the first option for mild-to-moderate CTS. However, the comparisons between extracorporeal shock wave therapy (ESWT) and other non-surgical methods in the treatment of mild-to-moderate CTS remain controversial, and an updated systematic review is needed.

Methods: An electronic search was performed, and all available articles until August 2023 were included in the analysis. The overall quality of evidence was assessed by the GRADE approach. Meta-analyses were conducted using Manager V.5.3.3. Pooled effect sizes were expressed as the weighted mean difference (WMD) with 95% confidence intervals (CIs).

Results: A total of 19 RCTs were included. Low-level quality evidence showed that ESWT outperformed the control intervention in terms of functional improvements, pain relief, electrodiagnostic parameters, and cross-sectional area of the median nerve at any time point of follow-up. Compared to local corticosteroid injection (LCI), there were statistically better improvements in functional improvements, pain relief, and electrodiagnostic parameters at 3 and 6 months of follow-up.

Conclusions: There is low-level quality evidence to show that both fESWT and rESWT are more clinically effective than controls in symptom relief, functional enhancement, and electrophysiologic parameters' improvement for patients with mild-to-moderate CTS at any time point of follow-up. Compared with LCI, ESWT yielded similar short-term (<1 month) but better medium- (1-6 months) and long-term (>6 months) improvements in pain relief and functional recovery with fewer potential complications.

Keywords: carpal tunnel syndrome; extracorporeal shock wave therapy; local corticosteroid injection; meta-analysis; systematic review.

Figure 1

Flow chart of literature retrieval.

Figure 2

Risk of bias graph: (A) Graph of the risk of bias for the included studies; (B) graph of the risk of bias summary for the included studies [25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43]. “+”: low risk, “−”: high risk, “?”: unclear risk.

Figure 3

Meta-analysis of ESWT versus control: ΔBoston questionnaire score at 1-month, 3-month, and 6-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [27,29,30,31,32,33,38,41,42].

Figure 4

Meta-analysis of ESWT versus control: ΔVAS at 1-month and 3-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [29,30,31,33,37,38,41,42].

Figure 5

Meta-analysis of ESWT versus control: ΔSNCV at 1-month and 3-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [27,29,32,38,42].

Figure 6

Meta-analysis of ESWT versus control: ΔCSA at 1-month and 3-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [27,32,42].

Figure 7

Meta-analysis of ESWT versus LCI: ΔBoston questionnaire score at 1-month, 3-month, and 6-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [25,26,39,40,43].

Figure 8

Meta-analysis of ESWT versus LCI: ΔVAS at 1-month, 3-month, and 6-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [25,26,35,39,40,43].

Figure 9

Meta-analysis of ESWT versus LCI: ΔSNAP at 1-month and 3-month follow-up; ΔCMAP at 1-month and 3-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [25,26,35,39,43].

Figure 10

Meta-analysis of ESWT versus LCI: ΔSDL at 3-month follow-up; ΔMDL at 1-month and 3-month follow-up. The green squares represent the effect estimate of the individual studies and the horizontal lines indicate the confidence interval, and the dimension of the square reflects the weight of each study. The black diamond represents the combined point estimate and confidence intervals [25,26,35,39,40,43].