Extracorporeal Shockwave Therapy for Treating Chronic Low Back Pain: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Abstract

Objective: To assess the effectiveness and safety of extracorporeal shockwave therapy (ESWT) for the treatment of chronic low back pain (CLBP).

Methods: This was a systematic review and meta-analysis of randomized controlled trials (RCTs) designed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analysis statement standard. We identified relevant studies by searching multiple electronic databases, trial registries, and websites up to April 30, 2021, and examining reference lists. We selected RCTs that compared ESWT, in unimodal or multimodal therapeutic approaches, with sham ESWT or other active therapies. Two investigators independently extracted data and assessed the risk of bias and quality of the evidence. The main outcomes were pain intensity and disability status, examined as standardized mean differences (SMD) with 95% confidence intervals (CI). The risk of bias was assessed by using Cochrane Back and Neck (CBN) Group risk of bias tool and Jadad score, and GRADE was applied to determine the confidence in effect estimates. Heterogeneity was explored using sensitivity analysis and meta-regression.

Results: Ten RCTs, including a total of 455 young to middle-aged individuals (29.2-55.8 years), were identified. Compared with control, the ESWT group showed lower pain intensity at month 1 (SMD = -0.81, 95% CI -1.21 to -0.42), as well as lower disability score at month 1 (SMD = -1.45, 95% CI -2.68 to -0.22) and at month 3 (SMD = -0.69, 95% CI -1.08 to -0.31). No serious shockwave-related adverse events were reported.

Conclusion: The use of ESWT in CLBP patients results in significant and quantifiable reductions in pain and disability in the short term. However, further well-conducted RCTs are necessary for building high-quality evidence and promoting the application of ESWT in clinical practice.

Figure 1

Flow diagram of the selection of studies.

Figure 2

Risk of bias assessment of the included studies using the Cochrane Back and Neck Group (CBN) risk of bias tools.

Figure 3

Standardized mean difference (SMD) with 95% confidence intervals (CI) of pain intensity at month 1 (a) and month 3 (b) for extracorporeal shock wave therapy (ESWT) versus comparators for chronic low back pain. Pooled SMD calculated by random-effects model.

Figure 4

Standardized mean difference (SMD) with 95% confidence intervals (CI) of disability score at month 1 (a) and month 3 (b) for extracorporeal shock wave therapy (ESWT) versus comparators for chronic low back pain. Pooled SMD calculated by random-effects model.