Extracorporeal Shockwave Therapy as an Adjunctive Therapy for Frozen Shoulder: A Systematic Review and Meta-analysis
One page on PainSci cites Zhang 2022: Does Ultrasound or Shockwave Therapy Work?
PainSci notes on Zhang 2022:
One of many examples of a “positive” review of shockwave therapy, in this case for frozen shoulder. They reviewed “limited” data and reported what “seems to be beneficial” results … in the short term only … and not that much benefit … and even less benefit over time.
The greatest reported benefit was on “immediate” pain relief. Less for “short term.” And less still for long term! The long-term data “were heterogeneous, and the conclusions were not reliable.”
And even for immediate analgesia, we’re talking about a barely-there effect, just over the line.
How do I say this nicely? For people with frozen shoulder, very unreliable evidence of minor-at-best improvements in pain or function over a year or so is not a positive result. That’s not helping! 😡 Shockwave is just sucking money out of their wallet while they continue to have essentially the same experience of that extremely frustrating condition … even if the small benefit is real, which it probably isn’t!
Common issues and characteristics relevant to this paper: ?Scientific papers have many common characteristics, flaws, and limitations, and many of these are rarely or never acknowledged in the paper itself, or even by other reviewers. I have reviewed thousands of papers, and described many of these issues literally hundreds of times. Eventually I got sick of repeating myself, and so now I just refer to a list common characteristics, especially flaws. Not every single one of them applies perfectly to every paper, but if something is listed here, it is relevant in some way. Note that in the case of reviews, the issue may apply to the science being reviewed, and not the review itself.
- Garbage in, garbage out — not enough good quality data to meaningfully review/analyze.
- A high (and possibly unacknowledged) risk of bias and its consequences (p-hacking, etc).
original abstract †Abstracts here may not perfectly match originals, for a variety of technical and practical reasons. Some abstacts are truncated for my purposes here, if they are particularly long-winded and unhelpful. I occasionally add clarifying notes. And I make some minor corrections.
BACKGROUND: The best nonsurgical treatment for frozen shoulder is still unclear. Extracorporeal shockwave therapy (ESWT) is an innovative adjunctive treatment for frozen shoulder, but its effect is still unclear.
PURPOSE: To evaluate the published literature regarding the potential of ESWT as an adjunctive therapy for frozen shoulder.
STUDY DESIGN: Systematic review; Level of evidence, 1.
METHODS: Searches were conducted in the PubMed, EMBASE, Cochrane Library, China National Knowledge Infrastructure (CNKI), and VIP Information databases for relevant studies between inception and November 2020. Included were randomized controlled trials (RCTs) for frozen shoulder that compared ESWT with routine treatments to controls. There were no restrictions on the treatment period, type of ESWT, or severity of symptoms. At least 1 of the following outcome indices was assessed: visual analog scale (VAS) for pain, Constant-Murley score (CMS) for shoulder function assessment, or external rotation range of movement (ER ROM). RevMan 5.3 software was used to evaluate the bias and quality of the included studies. For continuous variables, the mean difference (MD) or standardized MD (SMD) with the 95% CI was extracted. For dichotomous data, event ratios and sample sizes were extracted.
RESULTS: Overall, 20 studies were included. The ESWT used as an adjunct to other interventions had better outcomes compared with control groups regarding immediate and short-term analgesic effects (immediate: MD, -1.10 [95% CI, -1.27 to -0.92], P < .00001; short-term: MD, -0.72 [95% CI, -0.94 to -0.50], P < .00001) as well as immediate function (SMD, 1.54 [95% CI, 1.19 to 1.89], P < .00001], I2 = 0%). There was significant heterogeneity between studies for long-term analgesia (MD, -0.90 [95% CI, -1.40 to -0.41], P < .00001, I2 = 89%) and ER ROM (MD, 10.31 [95% CI, 3.46 to 17.17], P < .003, I2 = 93%).
CONCLUSION: ESWT seems to be beneficial to patients with frozen shoulder by alleviating pain and improving function. ESWT could be used as an adjunct therapy to routine treatments, although the quality of the included RCTs was hampered by significant heterogeneity regarding long-term analgesia and joint ROM.
This page is part of the PainScience BIBLIOGRAPHY, which contains plain language summaries of thousands of scientific papers & others sources. It’s like a highly specialized blog. A few highlights:
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- Cannabidiol (CBD) products for pain: ineffective, expensive, and with potential harms. Moore 2023 J Pain.