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Comparison of safety between endoscopic and open carpal tunnel release

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Comparison of safety between endoscopic and open carpal tunnel release

Vol: 5| Issue: 3| Number:113| ISSN#: 2564-2537
Study Type:Meta-analysis/Systematic Review
OE Level Evidence:1
Journal Level of Evidence:1

Endoscopic and Open Release Similarly Safe for the Treatment of Carpal Tunnel Syndrome. A Systematic Review and Meta-Analysis

PLoS One. 2015 Dec 16;10(12):e0143683

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27 randomized and quasi-randomized trials that investigated safety outcomes in patients undergoing either endoscopic or open carpal tunnel release for carpal tunnel syndrome were included in this meta-analysis. The study was conducted to determine whether earlier concerns regarding the safety of endoscopic release in comparison to an open approach were still applicable presently. The study found that previous drawbacks of an endoscopic release such as high reoccurrence and reoperation rates have been gradually lessened to where they are now comparable with rates in an open approach. Total and major complications are also comparable between groups, whereas minor occurrences were significantly less frequent following endoscopic release. Return to activity was significantly earlier following endoscopic release compared to open release.

Publication Funding Details +
Non-Industry funded
European Research Council

Risk of Bias


Reporting Criteria


Fragility Index


Were the search methods used to find evidence (original research) on the primary question or questions stated?

Was the search for evidence reasonably comprehensive?

Were the criteria used for deciding which studies to include in the overview reported?

Was the bias in the selection of studies avoided?

Were the criteria used for assessing the validity of the included studies reported?

Was the validity of all of the studies referred to in the text assessed with use of appropriate criteria (either in selecting the studies for inclusion or in analyzing the studies that were cited)?

Were the methods used to combine the findings of the relevant studies (to reach a conclusion) reported?

Were the findings of the relevant studies combined appropriately relative to the primary question that the overview addresses?

Were the conclusions made by the author or authors supported by the data and or analysis reported in the overview?

How would you rate the scientific quality of this evidence?

Yes = 1

Uncertain = 0.5

Not Relevant = 0

No = 0

The Reporting Criteria Assessment evaluates the transparency with which authors report the methodological and trial characteristics of the trial within the publication. The assessment is divided into five categories which are presented below.




Accessing Data


Analysing Data





Detsky AS, Naylor CD, O'Rourke K, McGeer AJ, L'Abbé KA. J Clin Epidemiol. 1992;45:255-65

The Fragility Index is a tool that aids in the interpretation of significant findings, providing a measure of strength for a result. The Fragility Index represents the number of consecutive events that need to be added to a dichotomous outcome to make the finding no longer significant. A small number represents a weaker finding and a large number represents a stronger finding.

Why was this study needed now?

Open surgery was traditionally used for carpal tunnel ligament (TCL) release, though more recently, the use of endoscopic release has gained popularity. While the reduced invasiveness of endoscopic carpal tunnel release (ECTR) offers theoretical advantages related to morbidity, early studies suggested that complication rate was in fact increased following ECTR compared to open carpal tunnel release (OCTR), which was largely attributed by authors to the reduced operative field through which surgeons were working. More recent randomized controlled trials have found similar complications rates between the two approaches though there is still considerable debate regarding the comparative efficacy and safety between the two.

What was the principal research question?

How safe is endoscopic carpal tunnel release as compared to open carpal tunnel release for treatment of carpal tunnel syndrome?

Study Characteristics -
Data Source:
An online search of MEDLINE (Jan 1966 to Nov 2013), EMBASE (Jan 1980 to Nov 2013), the Cochrane Neuromuscular Disease Group Specialized Register (Nov 2013) and CENTRAL (The Cochrane Library; Issue 1; 2103) was conducted to identify any literature relevant to this report. A manual search of reference lists of included studies was also completed to identify any overlooked articles.
Index Terms:
Index terms not provided in the publication.
Study Selection:
Randomized and quasi-randomized controlled trials comparing OCTR to ECTR in patients with primary CTS, regardless of additional interventions or language of publication, were selected for inclusion. Any studies that involved minimal incision techniques for OCTR or were comparing endoscopic techniques to each other were excluded. 27 randomized and quasi-randomized trials, 4 of which were abstracts, were selected for inclusion.
Data Extraction:
Data was extracted into a standardized form independently by two authors.
Data Synthesis:
Analyses was performed in Stata (StataCorp, 2011) using a random-effects model in the inverse-variance method. Dichotomous outcomes were described using a odds ratio (OR) while continuous outcomes were reported using mean differences (MD). Predictive, or 95% confidence intervals (CI) were also provided. Heterogeneity standard deviation (SD) was calculated using moments. Meta-regression was used to determine time trends in the safety of the procedures by assessing differences in studies in terms of year of publication. If 0 events were reported in a group, a continuity correction of 0.5 was added, a different imputation method was used, or Bayesian data synthesis was used in a sensitivity analysis. The number of complications was modeled using Poisson likelihood. A low publication bias was assumed and further assessed using a funnel plot.

What were the important findings?

  • The pooled results from 15 studies found no significant difference between carpal tunnel release approaches for data on recurrence (ECTR=24/878; OCTR=19/806; OR=1.02 [95%CI 0.55, 1.90]).
  • Pooled incidence of reoperation from 11 studies demonstrated no significant difference between ETCR (20/869) and OTCR (8/727) (OR=1.36 [95%CI 0.61, 3.00]).
  • From 25 studies, the incidence of major complications was both infrequent and similar between ECTR (12/1366) and OCTR (12/1199) (OR=1.00 [95%CI 0.44, 2.27]).
  • From 24 studies, the incidence of minor complications was significantly lower following ECTR (63/1275) versus OCTR (120/1167) (OR=0.50; [95%CI 0.31, 0.82]). Sub-analysis of specific types of minor complications demonstrated a significantly higher rate of transient neuropraxia following ECTR compared to OCTR (OR=0.242 [95%CI 1.22, 4.80]), and a significantly lower rate of wound healing or scar problems with ECTR compared to OCTR (OR=0.24 [95%CI 0.15, 0.40]).
  • In terms of total complications, results were comparable between the two groups (24 studies; ECRT=119/OCRT=159; OR=0.82; 95% CI 0.52, 1.51), however heterogeneity was high among studies.
  • Patients who underwent ECTR returned to work significantly sooner than those OCTR (6 studies; MD=-9.56; 95% CI -12.51, -6.60), however there was high heterogeneity among studies.
  • Outcomes were consistent in a post hoc sensitivity analysis that excluded studies with a high risk of bias for allocation concealment.

What should I remember most?

In patients with carpal tunnel syndrome undergoing surgical release with either an open or endoscopic approach, no significant differences in pooled incidences of reoccurrence or reoperation were observed. Total and major complications were also comparable between open and endoscopic release, whereas minor complications occurred less frequently following endoscopic release. Nevertheless, within minor complications, an endoscopic release was associated with a significantly higher risk of transient neuropraxia, whereas open release was associated with a high risk of wound healing and scarring problems. A significantly earlier return to work was also noted following endoscopic release compared to open release.

How will this affect the care of my patients?

This analysis suggests that previous drawback of endoscopic carpal tunnel release being unsafe in comparison to open release in carpal tunnel syndrome may no longer be a concern. Rates of reoperation, reoccurrence, and complications were comparable between techniques and endoscopic release patients additionally exhibited a significantly faster return to activity. Studies with smaller populations tended to favour OCTR; however, these were generally studies published in the earlier years, and effect sizes could potentially be explained by a learning curve. As concerns of low study quality are expressed throughout this report, a further analysis with inclusion being limited to only high-quality trials is warranted.

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