Stemless total shoulder - is there spin in the abstracts?

Recently I've posted on 

Spin in abstracts on the subacromial balloon

Spin in abstracts on the augmented glenoid

Spin in abstracts on superior capsular reconstruction

Now we have the opportunity to consider spin in abstracts on the stemless total shoulder arthroplasty 

The stated goal of Evaluation of Spin in the Abstracts of Systematic Reviews and Meta-Analyses of Stemless Total Shoulder Arthroplasty was to identify and detail incidence of spin in the abstracts of systematic reviews and meta-analyses of stemless component total shoulde arthroplasty (TSA). The secondary goal was to investigate general study characteristics and describe patterns in relation to spin.

The authors point out that surgeons tend to read only the abstracts of publications, thus assessing spin in abstracts is important.

The details of their analysis is similar to that presented in Spin in abstracts on the augmented glenoid.

Basically the types of spin are:

Authors hide or do not present any conflict of interest 

Selective reporting of or overemphasis on efficacy outcomes or analysis favoring the beneficial effect of the experimental intervention 

Selective reporting of or overemphasis on harm outcomes or analysis favoring the safety of the experimental intervention 

Failure to specify the direction of the effect when it favors the control intervention 

Failure to report a wide confidence interval of estimates 

The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studiesThe conclusion claims the beneficial effect of the experimental treatment despite reporting bias. 

The conclusion formulates recommendations for clinical practice not supported by the findings 

The conclusion claims safety based on non-statistically significant results with a wide confidence interval 

The conclusion focuses selectively on statistically significant efficacy outcome 

The conclusion claims equivalence or comparable effectiveness for non-statistically significant results with a wide confidence interval 

The conclusion extrapolates the review findings to a different intervention (e.g., claiming efficacy of one specific intervention although the review covered a class of several interventions) 

Conclusion extrapolates the review's findings from a surrogate marker or a specific outcome to the global improvement of the disease 

Conclusion extrapolates the review's findings to a different population or setting 

The authors analyzed 12 articles. At  least 1 form of spin was observed in 10/12 (83.3%) studies. The most common type of spin was

“The conclusion claims the beneficial effect of the experimental treatment despite a high risk of bias in primary studies”, which was found in 7/12 (58.3%) studies. 

The three other common types of spin identified were

"The conclusion claims safety based on non-statistically significant results with a wide confidence interval"

"Authors hide or do not present any conflict of interest" 

"The conclusion formulates recommendations for clinical practice not supported by the findings"

According to  AMSTAR 2, 11/12 (91.7%) of studies had confidence ratings of “low” or “critically low” due to one or more critical flaws.

The authors concluded that "spin is prevalent in abstracts of systematic reviews and meta-analyses covering stemless TSA. Reporting more favorable outcomes is the most common type and physicians should be aware of this when making clinical decisions based on research". Authors tended to neglect the evaluation of primary study bias in their methodology; instead the discussion focused mainly on advantages of the stemless design.

Risk of overestimating the clinical importance of the stemless component TSA due to spin is especially relevant when contextualized within current literature on the topic. Romeo et al and Wiater et al recently performed two large, multicenter, prospective, blinded randomized controlled trials evaluating short-term clinical and radiographic outcomes of stemless implants against their traditional stemmed counterparts. Both studies found a lack of significant difference between stemmed and stemless component clinical outcomes, complications, and reoperation rates within a 2-year follow-up period. Additionally, the authors were careful to describe stemless implant performance as “noninferior,” “safe,” “effective,” or “promising.”Their findings are in contrast to the beneficial effect spinning that was most pervasive across the systematic reviews analyzed in the current study and suggest a pattern of overly optimistic conclusion-drawing despite RCTs that do not yet paint such a positive picture of the stemless technology.

Conclusion:

This study does not provide new evidence of the case for or against the use of a stemless humeral component. It does suggest that authors should attempt to avoid spinning their abstractions by making sure that the conclusions regarding safety and clinically (not only statistically) significant benefit are supported by robust evidence and that conflicts of interest and other sources of bias are made explicit.

Spin is not always bad, here are male and female redtail hawks spinning in courtship.

Red tailed hawks courting

Union Bay Natural Area

March 2021

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Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link).
The total shoulder arthroplasty (see this link).
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)
Shoulder rehabilitation exercises (see this link).