CSAW See-saws

Orthopaedics is really one of the last frontiers of evidence-based medicine.  In this field, there are few high-quality, randomised trials to tell us what works, what harms and what is just a waste of time.  In recent years we have seen some procedures put under the arthroscope and examined by the numbers.  Notably, the very common arthroscopic knee surgery has been compared to a sham procedure (NEJM, 2002) and… not a winner. In the last few years knee arthroscopy has been examined in a systematic review (BMJ 2015)… not any clear benefit over small harms…. so there we are – time to rethink our approach to knee surgery.

So today I am reviewing another new RCT that looks at arthroscopic subacromial decompression surgery for the shoulder.  The CSAW [Can Shoulder Arthroscopy Work?] trial was published in the Lancet in November 2017.  There was also an accompanying editorial commentary in the same issue.  If you read the headlines and the commentary on this paper then the conclusion seems to be pretty clear – there is NO demonstrable short-term benefit to subacromial decompression when compared to placebo surgery or no intervention.  So… is shoulder scoping just as useful as knee scopes?  Well in order to answer that question we need to look closely at the trial and see what it really can tell us.  Here we go.


The final trial included 313 middle-aged patients recruited from 32 hospitals in the NHS system of the United Kingdom. Patients had to have:

  • subacromial pain of at least 3 months’ duration
  • with intact rotator cuff tendons, patients with partial tears were included
  • previously completed a non-operative management programme that included both exercise therapy and at least one steroid injection.
  • The diagnosis was confirmed by a consultant shoulder surgeon

I think this is a reasonable group to examine and reflects the people we see in primary care. In the Australian context, 3 months would be a relatively short period of time to wait before considering surgery.  However, most patients in this trial then waited a further few months before undergoing the intervention.

The baseline stats were equal across the groups.. nothing to see here out of the ordinary.


The patients were randomised into 3 groups 1:1:1 including 2 surgical groups.

The first operative group underwent arthroscopic subacromial decompression under GA.  This included all the usual Orthopaedic scraping and debriding of bits of anatomy that most of us long forgot in Medical School.  This surgery required 2 arthroscopic ports.

The second group served as a “sham” surgery group.  These patients underwent an investigational arthroscope under GA.  A camera port was inserted to look and record the pathology, the joint was irrigated and a second sham port incision was made to keep the blinding intact.

Importantly both of the “surgical groups” then received between 1 and 4 postoperative physiotherapy sessions.  This may, therefore, be seen as part of the intervention. It was not purely a trial of surgery, but of Physio too.  Would it have been reasonably easy to get some Physio sessions for the control group too? This may have created a more precise intervention control setup?


The third control group underwent no treatment – they received no prescribed physiotherapy, steroid injections or other active therapy.  They attended a follow-up appointment with a shoulder surgeon at 3-months post randomisation.


The primary outcome was the Oxford Shoulder Score – a 48 point questionnaire looking at shoulder pain and functional outcomes.  This was recorded at 6 months after trial entry and was repeated at 12 months as a secondary outcome.  They also recorded a series of other pain and functional alphabet scores – 6 of them! [a set-up for p-hacking?]  They also recorded any adverse outcomes.  Now, it is hard to say exactly what a clinically-significant Oxford score shift would look like.  It is a patient-oriented outcome as it includes measures of pain and function.  I am a litlte wary of these patient questionnaire outcomes – when you think about it they are actually a composite of a dozen individual outcomes and that can be hard to interpret – however, it is what we tend to measure in such trials.  Maybe it would be better to ask patients a simple binary question eg. : “Are you able to do what you need to do?”


Using a two-sided t-test, 90% power to detect a difference in the Oxford Shoulder Score of 4·5 (SD 9·0), with a 5% level of significance required a sample size of 85 participants in each group.  They aimed to recruit 100 patients per group anticipating 15% drop out rate….

… and that is pretty much what happened!  The groups included 106, 103 and 104 at randomisation.  At 6 months only 90, 94 and 90 had data for analysis.  But, there is always a but…

  • only 76 of those randomised to active surgery had received it.
  • only 60 in the “sham surgery” group had received the stated intervention
  • and of the 104 in the control group 11 ended up with some form of surgical decompression at 6 months….

So if you are following the numbers here – we are slipping well below power and the control group is not exactly a true control group.  So anything we say after this point requires a pinch of salt thrown over the [sore] shoulder.


Summary – there was not much difference between the 2 surgical groups.  If anything, the “scope only” / sham surgery group were slightly better off at the six-month mark!  When compared to the control group there was a small but insignificant improvement in the Oxford Shoulder Scores.

Probably the most useful and scientifically robust data to take away from all this is that the patients tended to get better no matter what the doctors did!!  There was an average 12-point improvement across the board which was much larger than differences observed between groups.

You could argue that the gap between the green line of “no treatment” and the “surgical” groups is opening up at 12 months… but recall that this trial was not powered for this as a primary outcome and that the drop out rate at 12 months was increasing.

Also at the 12-month mark, the “no treatment group” included 24 patients who had some surgery.

On the downside of the data – there were few adverse outcomes. there were 2 “frozen shoulders” in each group… small numbers, meh!


It is great that we are seeing more randomised evidence in Orthopaedics, especially for the bread ‘n butter clinical problems like knee and shoulder pain.  This trial has a reasonable design and the use of the sham surgery gives us a chance to detect important differences between placebo and actual surgery.

Unfortunately, the CSAW trial suffered as a result of the non-adherence and delays to protocols.  The headlines state that there was no difference between groups, however, this study lacked the statistical power to make any hard claims about the differences.

So, what can we say with this data?

Option 1:  Agree with the headlines and commentary.  There is no clinically significant difference between the three groups.  Shoulder decompression is not worth it.. use a tincture of time, maybe some physiotherapy and the patient will improve either way.

Option 2:  Disagree.  Consider that this is flawed data and that it is giving arthroscopic shoulder decompression an unfair trial.  I frequently lambast trials which claim a benefit for various drugs based on flawed data or analysis.  So to be fair, on the flipside, we cannot draw conclusions about non-superiority from this small, flawed data set.

There are issues around the trial’s internal validity – high drop out and contamination of groups.  If anything this would tend to dilute the potential effects of surgery.  So that means we need to draw breath before dismissing the null hypothesis here.

If we accept that the data is weak, then we are left to Bayesian pondering.  In order to integrate this new data into our worldview (aka current practice) we need to know the prior likelihood that the surgery was beneficial… and this is where we come unstuck.  There just isn’t much quality data out there to form the prior.  Hence it comes down to where we think the onus of proof lies.  Do our Orthopaedic colleagues need to prove benefit OR is this surgery an established “standard of care” that needs to be disproved before we change tack?  ‘Tis a tricky ethical question.

Option 3:  Pragmatism.  The CSAW trial population had on average less than 6 months of pain/dysfunction and received 2 injections prior to entering the trial.  Maybe if the trial population had more severe or longer duration of symptoms then a larger benefit may have been seen.  When I discussed this with my local team they all agreed that they would not usually refer a patient for surgery after only 3 or 6 months.  They would usually opt for a prolonged period of physical therapy and injections or another analgesia options.  A Facebook poll on the GPDU doctors averaged out at around 9 months before referral to a surgeon… of course, it depends on your system as to how long the wait might take to actually see a surgeon and then receive intervention!

If we opted to offer surgery to only those with prolonged, refractory or severe symptoms I imagine we would be more likely to see a benefit and would certainly save a lot of resources.  As is the case with many conditions – the symptoms will decrease over time for many patients, so selecting only those with significant and persistent symptoms might result in more bang for the arthroscopic buck.

Thanks to Dr Michael Tam ( evidencebasedmedicine blog ) for providing pre-publication peer review and insights around the nitty gritty of stats in this article.

First 10EM Journal Club: January 2018

It is a New Year but the same old Journal club with Dr Justin Morgenstern.

This month we are tackling a few papers on the futility PEs ( pulmonary emboli and pelvic examinations), the worst APO paper ever and the reason you should wear a cape to work.  If that sounds like your sort of thing then tune in and have a listen as we dissect the data.

You can read along with the original papers in full PDF below.  As always – we value your feedback and comments.

Justin’s written summary is over at First10EM

Here’s the papers in PDF:

Ganshorn H, Sheldon R. Prevalence of pulmonary embolism in patients presenting with syncope. A systematic review and meta-analysis. The American journal of emergency medicine. 2017; PMID: 28947223

Beck KS, et al. Incidental Pulmonary Embolism After Coronary Artery Bypass Surgery: Long-Term Clinical Follow-Up. American journal of roentgenology. 2018; 210(1):52-57. PMID: 29064757

Linden JA, Grimmnitz B, Hagopian L.  Is the Pelvic Examination Still Crucial in Patients Presenting to the Emergency Department With Vaginal Bleeding or Abdominal Pain When an Intrauterine Pregnancy Is Identified on Ultrasonography? A Randomized Controlled Trial. Annals of emergency medicine. 2017; 70(6):825-834. PMID: 28935285

Isoardi K. Review article: the use of pelvic examination within the emergency department in the assessment of early pregnancy bleeding. Emergency medicine Australasia. 2009; 21(6):440-8. PMID: 20002713

Rosenbaum L.  The Less-Is-More Crusade – Are We Overmedicalizing or Oversimplifying? The New England journal of medicine. 2017; 377(24):2392-2397. PMID: 29236644

Lapage MJ, Bradley DJ, Dick M. Verapamil in infants: an exaggerated fear? Pediatric cardiology. 2013; 34(7):1532-4. PMID: 23800976

Cantrell FL, Cantrell P, Wen A, Gerona R. Epinephrine Concentrations in EpiPens After the Expiration Date. Annals of internal medicine. 2017; 166(12):918-919. PMID: 28492859

Matsue Y, Damman K, Voors AA. Time-to-Furosemide Treatment and Mortality in Patients Hospitalized With Acute Heart Failure. Journal of the American College of Cardiology. 2017; 69(25):3042-3051. PMID: 28641794

White RE, Prager EO, Schaefer C, Kross E, Duckworth AL, Carlson SM. The “Batman Effect”: Improving Perseverance in Young Children. Child development. 2017; 88(5):1563-1571. PMID: 27982409

 Here is the audio:

2017 Wrap Up

It is that time of year. Once again we reach that arbitrary point in space in which we reset our calendar, drink too much and reminisce about the birth of an idealistic, Iron- Age, itinerant carpenter. As is traditional, I would like to spend a moment reflecting on the events that have occurred during this last lap of Helios.

2017 has been a good year for the FOAMed family. There has been a lot to learn and share. The never-ending novelty of new faces and familiar, inspiring clinicians has kept us all entranced and enthused. The strongest theme emerging from the community this year has been one of inclusiveness and equality.

The amazing women who ‘FOAM’ have asserted their strong and sensible standing as leaders of our troupe. I for one am delighted to have such enlightened folk out here to ensure that we move forward with a culture of equality and unambiguous intolerance of those whom would marginalise or minimalize “minorities”.

The last part of this year we have seen the ugly reality of sexism and misogyny raise its head in all spheres of our culture. Mercifully, these heads have been consistently (with a few notable exceptions) beaten down. One senses that we are at the crest of the hill that our female friends have been climbing for many decades. I hope that going forward into the next orbit we can maintain this course and change the way we treat one another for good. So if you are looking for a New Year’s resolution that you can keep and not cost a penny – let it be this:

I will behave towards others based upon their actions, not their gender or ancestry.

If I hear or read language that degrades another’s sex or race I will speak up then and there – be it on the floor in ED or on Twitter.

I will acknowledge the difficulties and struggles that my colleagues have faced to get where they are on account o f their being born into this culture that favours men like me.

I will endeavour to ensure the next generation does not have to battle for what I take for granted.

As a white male leader it is my responsibility to model this behaviour in my workplace and online. Most importantly though – to do so for my three sons.

            There has been a global shift in our community. Although we have always been a truly international collaboration – this year has seen our friends in the LMICs increase in number and voice. One of the highlights of the DasSMACC conference was watching Dr Annet Alenyo tell her story and allow us all to understand how we can contribute to Africa’s emerging Emergency Medicine network.

Translating excellent care into a rural context is my passion. The challenge for us in the future is to not only translate the science of medicine into our own context (be that a remote Kimberley hospital or a clinic in the least resourced parts of Rwanda), next we need to start doing more research in these places. This research will change and improve our care, save money and other valuable, finite resources. However, without the assistance form our developed and already excellent centres this will be tough. The FOAMed community is in a great position to act as a bridge between these two worlds. Together we can make the world a better, brighter and more balanced place to live and do our important work.

I would like to single out a few people who have made the last year especially fun and fulfilling. This is by no means an exhaustive list. So many people have provided such great opportunities to collaborate and improve what I do at Broomedocs. So to all of you: a big fist bump and thankyou.

Dr Justin Morgenstern. The first time I read the First10EM blog I knew that Justin was a deep and reasoned thinker. In 2016 we started working together on the Journal Club podcast and I have learned so much about things that I never knew needed knowing. Now, he is a seriously busy young man who has deservedly become part of Canada’s phenomenal FOAM fellowship.It has been truly rewarding to share ideas, argue, but mostly agree with Justin. I hope you have all enjoyed our banter and we hope to keep it up into 2018. Thanks buddy!

Dr Andy Tagg. The best thing about FOAMed is developing friendships that grow and thrive over time. Andy and I first ‘worked’ together when he shared his most personal “Lesson Hard Learned” five years ago. Since then Andy has been the engine behind some of the finest FOAM out there: Don’t Forget the Bubbles blog, conference and workshops. He has been a leader in the Australian community to shine a light on the mental health and well being of our colleagues. In the last year I have been lucky enough to spend time with Andy and am grateful for the opportunities he has given me to be involved in his projects. (That reminds me – had better start prepping for DFTB 2018… see you there!

Dr Michelle Johnston I would like to thank Michelle for being Michelle. My FOAMed Twitter feed is eternally enriched by your words. In 2017 Michelle has achieved what we had all knew that she would do – she has become a published author. In a word: excellent. This is truly inspirational for those of us who love to write and do Medicine. I await my copy of Dustfall with breath held (to avoid inhaling asbestos particles…)  Specifically, I want to thank Michelle for her time and attention in editing and giving excellent feedback when I decided to write from the heart – a scary thing to do.

Dr Heidi James. Some of you might be wondering who Heidi is? Well she is a wonderful and wise GP from the eastside of Canada. Heidi has become the voice of the Primary Care RAP (not FOAMed… but really good anyway). If you want to hear what I mean then listen to her on the “Lessons Hard Learned” series or on this recent ERCast episode.  I am inspired by Heidi’s positive outlook both as a clinician and a parent. You bring so much humanity to your work and life and motivate me to be better at both.

Dr Tim Leeuwenburg. Yes, that rascal from the island off Adelaide. Tim and I have worked together on lots of stuff over the years and the last year has seen our partnership involved in some really fun and transformative projects. You may have noticed a slow down on the blog in recent months? Well that is largely because I have been working on some stuff that doesn’t show up on the FOAMEd frontline. As much fun as the FOAMed stuff is – there comes a point where one has to return one’s focus back on your own place. Tim has been a great ally in making this happen – we have developed new communities of like-minded rural doctors with the aim of applying all the cool stuff we learn online to the day-to-day coalface of rural practice.


As the year draws to a close I am taking some time away from the internet to go and explore some remote and beautiful parts of New Zealand with my family.  I will be back in 2018 with more of the same and some new stuff.  IN the meantime enjoy your January – be it shovelling snow in Canada or dodging sharks at the beach.  Thanks for all of your comments, contributions and ongoing connection.