MD, PhD, FMedSci, FSB, FRCP, FRCPEd

shoulder-pain

Systematic reviews are aimed at summarising and critically evaluating the evidence on a specific research question. They are the highest level of evidence and are more reliable than anything else we have. Therefore, they represent a most useful tool for both clinicians and researchers.

But there are, of course, exceptions. Take, for instance, this recent systematic review by researchers from the

  • Texas Chiropractic College, Pasadena, the Palmer Center for Chiropractic Research, Palmer College of Chiropractic, Davenport,
  • Department of Planning, Policy and Design, University of California, Irvine,
  • VA Puget Sound Health Care System, Tacoma,
  • New York Chiropractic College, Seneca Falls,
  • Logan University College of Chiropractic, Chesterfield,
  • University of Western States, Portland.

Its purpose was to evaluate the effectiveness of conservative non-drug, non-surgical interventions, either alone or in combination, for conditions of the shoulder. The review was conducted from March 2016 to November 2016 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), and was registered with PROSPERO. Eligibility criteria included randomized controlled trials (RCTs), systematic reviews, or meta-analyses studying adult patients with a shoulder diagnosis. Interventions qualified if they did not involve prescription medication or surgical procedures, although these could be used in the comparison group or groups. At least 2 independent reviewers assessed the quality of each study using the Scottish Intercollegiate Guidelines Network checklists. Shoulder conditions addressed were

  • shoulder impingement syndrome (SIS),
  • rotator cuff-associated disorders (RCs),
  • adhesive capsulitis (AC),
  • nonspecific shoulder pain.

Twenty-five systematic reviews and 44 RCTs met inclusion criteria. Low- to moderate-quality evidence supported the use of manual therapies for all 4 shoulder conditions. Exercise, particularly combined with physical therapy protocols, was beneficial for SIS and AC. For SIS, moderate evidence supported several passive modalities. For RC, physical therapy protocols were found beneficial but not superior to surgery in the long term. Moderate evidence supported extracorporeal shockwave therapy for calcific tendinitis RC. Low-level laser was the only modality for which there was moderate evidence supporting its use for all 4 conditions.

The authors concluded that the findings of this literature review may help inform practitioners who use conservative methods (eg, doctors of chiropractic, physical therapists, and other manual therapists) regarding the levels of evidence for modalities used for common shoulder conditions.

This review has so many defects that it would be boring to list them here.

The PRISMA guidelines  – I happen to be a co-author – state, for instance, that the abstract (the above text is from the abstract) should provide a structured summary including, as applicable: background; objectives; data sources; study eligibility criteria, participants, and interventions; study appraisal and synthesis methods; results; limitations; conclusions and implications of key findings; systematic review registration number. It is obvious that the review authors have omitted several of these items.

And that is just the abstract!  There is much, much more to criticise in this paper.

The most striking deficit, in my view, is the useless conclusion: the one from the abstract (the part of the paper that will be read most widely) could have been written before the review had even been started. It is therefore not based on the data presented. Crucially it does not match the stated aim of this review (“to evaluate the effectiveness of conservative…interventions”).

But why? Why did the authors bother to follow PRISMA? Why did they formulate this bizarre conclusion in their abstract? Why did they do a review in the first place?

I fear, the answers might be embarrassingly simple:

  • They only pretended to follow PRISMA guidelines because that gives their review a veneer of respectability.
  • They formulated the conclusions because otherwise they would have needed to state that the evidence for manual therapy is less than convincing.
  • They conducted the review to promote chiropractic, and when the data were not as they had hoped for, they just back-paddled in an attempt to hide the truth as much as possible.

If this were an isolated case, I would not have bothered to mention it. But sadly, in the realm of chiropractic (and alternative medicine in general) we currently witness a plethora of rubbish reviews (published by rubbish journals). To the naïve observer, they might look rigorous and therefore they will be taken seriously. The end-effect of this pollution of the literature with rubbish is that we get a false-positive impression about the validity of the treatments in question. Consequently, we will see a host of wrong decisions on all levels of healthcare.

The big question is: HOW DO WE PROTECT OURSELVES FROM THIS DANGEROUS TREND?

I only see one solution: completely disregard certain journals that have been identified to regularly publish nonsense. Sadly, the wider medical community is far from having arrived at this point. As far as I can see, the problem has not even been identified yet as a serious issue that needs addressing. For the foreseeable future, we will probably have to live with this type of pollution of our medical literature.

Acupuncture is often recommended as a treatment for shoulder pain, but its effectiveness is far from proven. A new study has just been published; but does it change this uncertainty?

A total of 227 patients with subacromial pain syndrome were recruited to this RCT. The patients were allocated to three groups who received either A) group exercise, B) group exercise plus acupuncture or C) group exercise plus electro-acupuncture. The primary outcome measure was the Oxford Shoulder Score. Follow-up was post treatment, and at 6 and 12 months. Data were analysed on intention-to-treat principles with imputation of missing values.

Treatment groups were similar at baseline. All treatment groups demonstrated improvements over time. Between-group estimates were, however, small and non-significant.

The authors concluded that neither acupuncture nor electro-acupuncture were found to be more beneficial than exercise alone in the treatment of subacromial pain syndrome. 

Well, that was to be expected!… I hear the rationalists amongst us exclaim.

Actually, I am not so sure.

One could easily have expected that the acupuncture groups (B and C) show a significant advantage over group A.

Why?

Because acupuncture is a ‘theatrical placebo’, a ritual that impresses patients and thus impacts on results, particularly on subjective outcomes like pain. If the results had shown a benefit for acupuncture + exercise (groups B and C) versus exercise alone (group A), what would we have made of it? Acupuncture fans would surely have claimed that it is evidence confirming acupuncture’s effectiveness. Sceptics, on the other hand, would have rightly insisted that it demonstrates nothing of the sort – it merely confirms that placebo effects can affect clinical outcomes such as pain.

As it turned out, however, this trial results happened to indicate that these placebo-effects can be so small that they fail to reach the level of statistical significance.

I think there is one noteworthy message here: RCTs with such a design (no adequate control for placebo effects) can easily generate false-positive results (in this case, this did not happen, but it was nevertheless a possible outcome). Such studies are popular but utterly useless: they don’t advance our knowledge one single iota. If that is so, we should not waste our resources on them because, in the final analysis, this is not ethical. In other words, we must stop funding research that has little or no chance of advancing our knowledge.

As I have mentioned before, I like positive news as much as the next person. Therefore, I am constantly on the look-out for recently published, sound evidence suggesting that  some form of alternative medicine is effective and safe for this or that condition. This new systematic review fits that description, I am pleased to report.

Its authors evaluated the effectiveness of massage therapy (MT) for neck and shoulder pain. Their extensive literature searches identified 12 high-quality studies. The meta-analyses showed significant effects of MT for neck pain and shoulder pain compared to inactive therapies. MT did not yield better effects for neck pain or shoulder pain than other active therapies administered to the control groups. Shoulder function was not significantly affected by MT. The authors concluded that “MT may provide immediate effects for neck and shoulder pain. However, MT does not show better effects on pain than other active therapies. No evidence suggests that MT is effective in functional status”.

Massage therapy is thus a promising treatment, particularly as this systematic review is by no means the only piece of encouraging evidence. It is not better than other effective treatments, but it is not associated with frequent or serious adverse effects. This means that the demonstrable benefits are likely to outweigh its risks; in other words, the risk benefit balance is positive. Regular readers of this blog will appreciate the importance of this point.

Massage is practiced by several professions: mostly, of course, by massage therapists, but occasionally also by nurses, osteopath, chiropractors etc. Chiropractors, in particular, have recently tried to make much – I think too much – of this fact. They tend to claim that, as they use treatments which are evidence-based, such as massage, chiropractic is an evidence-based profession. I think this is akin to surgeons claiming that all of surgery is evidence-based because surgeons use medications which effectively reduce post-operative pain. Chiropractors foremost employ spinal manipulation and surgeons foremost use surgery; if they want us to believe that their practice is evidence-based, they need to show us the evidence for their hall-mark interventions. In the case of surgery, the evidence is mostly established; in the case of chiropractic, it is mostly not.

Massage is backed by reasonably sound evidence not just for neck and shoulder pain but for a range of other conditions as well. WHAT DO WE CALL AN ALTERNATIVE MEDICINE THAT WORKS? WE CALL IT MEDICINE!

So why is massage not a mainstream therapy? The answer is simple: in many countries, massage therapy has long been considered to be entirely conventional. Twenty years ago, I was chair of rehabilitation medicine at the university of Vienna. Amongst my staff, there always were about 5-8 full time massage therapists and nobody thought this to be unusual in any way. Similarly, in Germany, massage is entirely conventional.

Perhaps it is time that the English-speaking countries catch up with Europe when it comes to massage therapy and the evidence that supports it?

Gravityscan Badge

Recent Comments

Note that comments can be edited for up to five minutes after they are first submitted.


Click here for a comprehensive list of recent comments.

Categories