Knee arthroscopy in arthritis: an evidence-practice mismatch

Osteoarthritis, where the cartilage lining a joint gets worn down, is common (Australian data, UK data, US data). Most people will get it if they live long enough, and the knee joint is commonly affected. There is little that can be done to repair or reverse this process, and a related paper that covers many osteoarthritis treatments shows that most of the things we do (analgesics, anti-inflammatory medication, injections etc.) only provide temporary relief, and many of them hardly work at all. Treatment, if severe enough, often means a knee replacement.

Knee replacement surgery is major surgery so it is only reserved for those with severe osteoarthritis. So what do surgeons do with patients who have knee pain and mild or moderate arthritis? They often do an arthroscopy: a low risk, day-only procedure that pays well and seems to work some of the time. Hundreds of thousands are done in the US every year, and in my state the rate of arthroscopy is high and is rising.

The trouble is: it doesn’t work. Most patients still have pain, some get worse, and about 20% will end up having a knee replacement within 2 years anyway. Feel free to skip to the last paragraph for the Bottom Line, or read on for the details.

Platelet Rich Plasma continues to unimpress

Further to my previous blog post on Platelet Rich Plasma (PRP), a recent review of five clinical trials of its use in rotator cuff repair surgery of the shoulder concluded:

"PRP does not have an effect on overall retear rates or shoulder-specific outcomes after arthroscopic rotator cuff repair."

And a systematic review of PRP in orthopaedic surgery concluded: 

"there is uncertainty about the evidence to support the increasing clinical use of platelet-rich plasma and autologous blood concentrates as a treatment modality for orthopaedic bone and soft-tissue injuries"

The scientific evidence for PRP's lack of effect builds, while its clinical use increases.

Doctors doctoring the research: fraud and error

I have been reading about publication retractions. They are scientific-speak for “Whoops”. This can either mean “Whoops, I made a mistake” (error), or “Whoops, you caught me” (fraud). It is sometimes hard to distinguish between them. Either way, it is another example of published research that is wrong, and it looks like there is little we can do to stop it.

How big is the problem? Why does it matter? Why does it happen? and How can we stop it?

How big is the problem?

The extent of the problem on an individual level can be seen on the Retraction Watch blog, but is best illustrated by the case of Dr Fujii, an anaesthetist from Japan who currently holds the record for the number of articles retracted (nearly 200), which is more than I have ever had published. But as he has not admitted any wrongdoing, we don’t know whether he is fraudulent, or whether he is a doctor who makes a LOT of mistakes. I am not sure which is worse.

Forget the pre-game stretch

Another example of something that sounds good, but isn’t. How many people in the world swear by their pre-game stretches? Or post-game stretches? Especially when there is so much evidence to the contrary.

Skeptic or cynic?

I am a skeptic, and I try not to be a cynic. Skeptics accept the scientific method and rational thinking as the best tools with which to evaluate claims and get closest to the truth. Skeptikos in Greek means to inquire, or find out. This can be hard work; being a cynic is easy.

Invasion of the robots

In my institution, the surgeons are keen to get some government money to turn us into a robotic surgery centre. I fear they are doing it for the reputation and the referrals, but this would be cynical rather than skeptical (see upcoming blog on the difference). So I will simply say that they are not doing it to benefit the patients. They may think they are, but I am not aware of any evidence that patient-based outcomes are better with robotic surgery. I am however, aware of empirical evidence that robots cost a lot, because I have seen the bill.

It turns out that robotic surgery is yet another example of something that sounds good, with some research showing improvements in some aspects, but with the whole thing falling down when it comes to improving patient health.

The MS cure, that isn't

A surgeon in Italy has developed an operation to treat MS (multiple sclerosis), based on a biological plausible theory, and he has reported good results after the treatment. As readers know, this is usually enough to get an operation accepted, and it is the only support behind many current operations. Readers should also know that these criteria do not provide proof of effectiveness. In this story though, it is the patients who have pushed for this treatment to be available.

Are doctors as good as they think they are?

Benjamin Spock, the American paediatrician, once said: “Trust yourself. You know more than you think you do”. That may be good advice for patients, but the opposite holds for doctors. We know that doctors overestimate the effectiveness of their treatments (a major theme of this blog), but it turns out that there is also a gap between their perceived knowledge of medicine and their actual knowledge. If you ask doctors how competent they are on a particular medical topic or skill (a subjective assessment) and then sit them down and test them on the same topic or skill (an objective assessment), you find a significant and consistent pattern: doctors think they are a lot better than they actually are. And it appears that surgeons (here and here) are not excluded.

Overdiagnosis: providing a solution when there is no problem

I just complain about it; these people are doing something about it. Overdiagnosis occurs when people who are healthy are diagnosed with a disease that will not ultimately harm or kill them. It is associated with over-medicalisation and leads to overtreatment and the associated risk of harm. It is a classic example of our tendency to assume that the more tests and treatments we get, the healthier we become. Often it is the opposite.

Don’t believe the hype, or the research

I spend a lot of time telling people to look for the rational, scientific evidence and to try to avoid the hype from marketers and doctors. But it seems that you can’t always believe the scientific evidence either, judging from quotes like this one from Marcia Angell, the former editor of the most respected and highly ranked medical journal in the world – the New England Journal of Medicine.

“It is simply no longer possible to believe much of the clinical research that is published, or to rely on the judgment of trusted physicians or authoritative medical guidelines. I take no pleasure in this conclusion, which I reached slowly and reluctantly over my two decades as an editor of The New England Journal of Medicine”

Lessons from history #1: The stress of modern life

Is the hustle and bustle of modern life causing you stress? Can’t cope with the constant barrage on your senses? Having trouble keeping up with the pace of advancement in science and technology? Then you are not alone. Here is a quote from an article in Scientific American highlighting the very problem. The thing is, it was written over 100 years ago.

“To point to the stress and hurry of modern city life as the cause of half of the ills people suffer today has become commonplace.

While we may imagine future generations of people perfectly calm among a hundred telephones and sleeping sweetly while airships whiz among countless electric wires over their heads and a perpetual night traffic of motor cars hurtles past their bedroom windows. As yet, our nervous systems are not so callous.”

                                                                                                                    (Scientific American, 1902)