Alt.orthopaedics: seal clubbing edition

A number of years ago I was in a teaching session with one of the UK orthopaedic greats, Richard Villar, who was the first person that I heard voice publicly what we had all begun to realise, "let's face it, our knee replacements, overall, are just not quite as good as our hip replacements".

He was right, and mostly it was not to do with surgical technique. Like with so many operations, success is predicated on good patient selection. Dissatisfaction is in up to 25% of patients, seriously.

By a poor outcome I don't mean infection, PE or any of the 'standard' complications. I am referring to - as was Ricky - the patient who is never quite satisfied with it, they have chronic non-mechanical pain, it "just doesn't feel right".

If only we could identify this group preoperatively. It would save them (and us) from considerable stress and disappointment.

There have been some valiant efforts. Our Edinburgh colleagues have produced quite a few papers on outcomes, looking at age, concomitant back pain, rather loosely defined 'surgical factors', mental disability, preoperative patient expectations, and 'general physical well being'. With all this data, does that mean we should refuse a TKR to someone with definite pain and severe arthritis, who unfortunately is a male under 55 years with back pain, poor mental health, not in great shape, and who has an expectation that TKR will solve everything?

The objective answer might be 'yes', but when you're with them in the clinic, it's not that simple.

Some Korean surgeons carefully reviewed all this in 2016, and with reference to the vexed issue of personality, stated the following:

Gong and Dong (27) retrospectively investigated the relationship between the outcomes of TKA and patient's personality classified into 4 types: patients with extroverted personality were more satisfied than those with introverted or anxious personality after TKA. In our opinion, however, the influence of personality on the outcome of TKA is not straightforward to determine due to the difficulty of categorizing various human personalities.

They have a point.

...oh dear

What to do?

Well, one of my esteemed colleagues, whom I will refer to as TBN, had been chatting to one of the more senior trainees about this conundrum, and they came up with the following suggestion. See what you think.

If in the outpatient clinic you have decided that someone might benefit from a TKR, they get directed to a separate cubicle, where they watch a video. It shows an Inuit in a snowy barren waste, and before him lies a seal, which he is beating to death with a heavy stick, assisted by a harpoon.

If the prospective TKR patient cries out that it's appalling and no animal should be subjected to that, then you might be better off with a Pain Clinic referral.

If, on the other hand, they say that he's just getting his tea, and in addition he could probably use a warm coat and some new boots**, then they can safely be added to the TKR waiting list.

Clearly this would need to be studied prospectively with an appropriately sized cohort***, but the technology is already there. It's already better than banning people because they're a bit overweight.





**Wikipedia: Traditionally, when an Inuit boy killed his first seal or caribou, a feast was held. The meat was an important source of fat, protein, vitamin A, vitamin B12 and iron, and the pelts were prized for their warmth

***There's already evidence that CBT (Cognitive behavioural therapy) can play a role in improving outcomes of bariatric and spinal surgery. A cure for catastrophising?

Achilles, Pascal, Occam, TUNC and Bonini

In the world of eponyms in surgery - Monteggia, Fournier, Chiari etc - I actually prefer the non-medical ones.

There is, for example, Achilles' Dilemma in hip resurfacing  ("to choose whether to live a short and glorious life or live a long and boring life"); Occam's Razor in diagnostics; Pascal's Wager in avoiding hip dislocation (just use an elevated lip - there is no down side). In case you're wondering, TUNC theory is an acronym not an eponym, for any confused readers.

Here, though, is a new one for me. Bonini's Paradox (courtesy of Kevin Williamson, writing on US politics).

Let us consider hip replacement first. A sphere sits within a hemisphere, as a near perfect fit. It can move freely in any direction for everyday function. It has intrinsic stability by nature of its shape. It is a fairly accurate facsimile of a real hip in many ways. It is a simple design philosophy, if subject to highly sophisticated manufacturing. It is very forgiving in practice, if you put it in slightly askew.

Not so knee replacement. Here there are several radii of curvature in coronal and sagittal planes, not one. A highly complex ligamentous arrangement ensures stability and translational movement. The lateral tibial plateau is smaller in life than the medial side. The lateral plateau has convexity. The shock absorption from the menisci varies between the two sides. Yet the knee prosthesis has a symmetrical biconcave tibial plateau with no difference in impact resistance, no benefit from the cruciates (except in those cruciate retaining cases with a pristine PCL), and relies on a difficult-to-consistently-get-right 'balancing' of the intact collaterals. It is a very unforgiving scenario, so no wonder that pretty much everyone admits these days that knee outcomes are poorer overall than those from hip replacement, particularly in high activity patients.

Attempts to make more complex knee replacements incorporating these issues have generally failed, with either poorer results or at best, unpredictable ones. It's not been for lack of trying by implant companies (1, 2).

Back to Bonini, who is a business professor at Stanford University, looking at reproducing complex systems, for example, a computer model of the brain:

And this is Bonini's Paradox: The less information a model carries about its subject, the less useful it's going to be in helping someone understand that subject. And yet, the more information a model carries about its subject, the less useful it's going to be in helping someone understand any single point of that subject. Any sufficiently detailed map of a region is going to be just as dense and difficult as the region itself. Any sufficiently detailed model of a brain is going to be a brain.

...and any sufficiently detailed model of a knee is going to be a knee. Wikipedia quotes French poet and philosopher Paul Valery, with a similar take, from years earlier in 1937: "Everything simple is false. Everything which is complex is unusable."

Indeed, a hip replacement is undoubtedly 'false', but it nearly always works. A more complex knee replacement is also false, but it just edges a little bit along the spectrum towards unusable.

Another quote from the Gizmodo article already cited: Any model, of anything, is in an act of editing. It picks out what we think is important regarding the subject, and directs our attention to how that important thing can be manipulated.

Even orthopaedic surgeons aren't gods. I suppose

...OK, everybody got that?

Country music meets total joint replacement

Nobody closes over an actively bleeding surgical site. Do they?

In my handwritten operation note it says 'haemostasis' followed by a tick symbol. In the dictated note I use the authoritative phrase 'haemostasis secured', which has a nice feel to it. Obviously I won't get any postoperative haematoma, and if I did, which I won't, it wouldn't be my fault. Or something.

So I will never have to use the phrase  'it was dry when I closed'.

In this matrix lesson, Leo Gordon notes the unusually fruitful use of Country & Western lyrics as applied to surgery, thus creating a new composition: 'Don't the Fields All Get Drier at Closing Time'. It's true that near the end of a big case you often just want to get out of there.  Songwise, one might add 'Does My Ring Hurt Your Finger' by Charley Pride, when examining for anal tone in a patient with a spinal presentation, or 'Life Has Its Little Ups and Downs' for when the MMC results come out (which has just happened)....



....I digress. Basically, not all complications are preventable, but bleeding is one that certainly can be. It doesn't help that in orthopaedics we've been trapped by what Gus Sarmiento aptly called 'the orthopaedic-industrial complex' as a variation on the medical-industrial complex theme (AKA Big Pharma), such that we dose all our arthroplasties with chemicals of extremely dubious value on the recommendation of physicians who are, to put it politely, remote from the consequences for the patient who has a bleeding complication.

Leo also describes the dreaded 'knee-jerk suspicion of surgical sloppiness' that we cannot banish from our mind when we confront the offending haematoma. Our own suspicion, and inevitably that of our friends and peers.

I blame Big Pharma, it was definitely dry when I closed.

An orthopaedic Christmas Carol, sort of

With a nod to Charles Dickens, this is about the ghosts of Orthopaedics Past, Orthopaedics Present and Orthopaedics Future. The reminiscences and reflections of surgeons late in their career or at retirement are a regular feature of this blog (label: wise surgeon). They really are  fascinating, and a treasure trove of useful thoughts.

This is Gordon Bannister, one of the best known British orthopods of the past 30 years, a very fine trainer and researcher, and generally a good guy, part of the Bristol centre of excellence.

He is no Luddite, but I draw your attention to a few things:

1. In the old days "senior consultant staff..had long since delegated acute trauma to their registrars. As a result, registrars acquired a wealth of experience". That's what happened to me much of the time. It doesn't happen now, which is both good and bad.

2. "At that time (the 80's) a 1:2 rota was common, occasionally tiredness ensued. The number of trainees increased whilst their experience declined". There is no way round this fact - you have to do the operations (and see the acute presentations) to get good. Most of my rotas were actually 1:3.  The promotion of the surrogate experience of 'simulated surgery' tells you how far things have gone. Note this from the former president of the RCS, Norman Williams. My view is that the New Deal has been even more damaging to training, morale and running a unit than the EWTD.

3. It was (and still should be) a lot of fun. If it consistently is not, then you may be in the wrong job.

4. I could not agree more that the demise of the true generalist to be replaced by self-anointed 'superspecialists' has been both stupid and damaging. It will be interesting to see what all the hip arthroscopy specialists will be doing in 10 years time.

Lastly, I would highlight the segment on NHS management and the conclusion. It's actually surprising how many empathetic and quality managers you encounter, but the long lasting damage wrought by the bad ones (and their political masters) is quite something.




(Thanks to BJJ News, September 2015)

Understanding knee arthroplasty and the PCL - not as boring as it sounds

Knee arthroplasty is more like hip resurfacing than it is like hip replacement - you really have to understand each stage in a relatively complex sequence, and if you get it wrong, it's not particularly forgiving. Likewise, if you understand each step then you can deal with the unexpected more easily and go off piste with a bit of freehand - if you have to (disclaimer: I am not promoting freehand knee replacement).

There are two keys to this in my view, once you're in the knee. One is understanding the PCL and its role in knee arthritis and knee replacement design. The other is the absolutely fundamental issue of mastering the flexion/extension gap. Wannabe knee surgeons have no excuse for getting the latter wrong.

The first piece is a chapter in a textbook from about 2001, which offers a practical take



As always, you learn more if you get two perspectives on the same topic. I read the second paper here back in the 90's, and I still think it's great, from the excellent AAOS review journal




For the record, I do a PCL sacrificing knee for pretty much ALL primary cases (and most revisions) - it works with almost any deformity and the fully audited long term outcomes are terrific.