It’s a pleasure to report, for once, scientific news that is crystal clear and unambiguous: surgery for osteoarthritis of the knee joint is really, really pointless. We’re talking about “debridement” — basically filing down rough knee cartilage. It sounds like a good idea, in a way. I know I want my knee cartilage to be smooth. Unfortunately, it doesn’t work, and any surgeon still recommending this procedure is out of touch.
For my readers, knowing about this is a valuable perspective on joint problems of all kinds — it really drives home one of the main themes of this website, which is that either:
Way back in 2002, fourteen years ago now, Moseley et al published the results of a fascinating experiment that showed that people who received a fake arthroscopic knee surgery for osteoarthritis had results just as good as people who received the real surgery.1 It’s unusual, by the way, for surgeons to compare real surgeries to fake surgeries, and that in itself was interesting. But the humungous placebo effect was the really sensational thing.
Since then, other researchers have generally been finding more and more bad news about athroscopic surgery for knee pain, culiminating earlier this year with what was arguably a scientific death blow for the procedure: a large review concluded that “there is ‘gold’ level evidence that arthoscopic debridement has no benefit.”2 This is now part of a general trend of discovering that surgeries don’t actually work,3 especially orthopedic (“carpentry”) surgeries.4
In 2008, the New England Journal of Medicine has added more experimental evidence to the pile, reporting that “surgery for osteoarthritis of the knee provides no additional benefit to optimized physical and medical therapy.”5
And then in 2013 the American Academy of Orthopaedic Surgeons echoed that sentiment in a comprehensive report on treatments for knee arthritis.6 They praised radical treatments like exercise, weight loss, and regular painkillers, and denounced several particularly ineffective treatments: acupuncture, glucosamine, chondroitin, “lube jobs” (injection of joint lubricant)… and surgical lavage and debridement. Their very own cash cow.
That integrity is extremely noteworthy: an association of surgeons denouncing a profitable, common surgical treatment! Dr. Harriet Hall:
Critics who claim doctors are just out to make money, take note: if they were the evil money-grubbers some make them out to be, wouldn’t these surgeons want to promote income-generating arthroscopic lavage and debridement? Wouldn’t they want to suppress information about conservative treatments and keep patients in pain until they were desperate enough to consent to expensive joint replacement surgery? Gee, do you suppose maybe they really are just trying to do what’s best for their patients?
In science, replication of experimental results is the most important way that our confidence in a conclusion increases. The more surprising and counter-intuitive experimental results seem to be, the more important it is to do it again. And again. And again. Every time you get the same results, or similar results, from different scientists, using different methods, the more confident you can be that those results have something to do with “the truth.”
Well, we just keep getting the same results about this. It’s not controversial. This is something everyone can agree on.
So please do not debride your knees! In fact, be cautious and skeptical about all surgeries that allege to fix mechanical problems with joints — although some of them undoubtedly work, they are all on probation.
This article has been about debridement. The situation is identical with another common knee surgery: meniscectomy, or trimming and “cleaning up” torn and frayed menisci, the pads of cartilage in the knee joint. There is a broad scientific consensus that it’s useless and risky for most patients.7 It’s no better than a sham,8 or exercise therapy9.
Meniscectomy has a strong obvious common sense vibe to it. It clearly seems like a really good idea. Degenerating menesci typically cause vividly “mechanical” knee trouble like locking, clunking, and buckling. Seems like cleaning that up a bit should be pure win, right? But the evidence is now overwhelming that it simply doesn’t do what educated, smart, well-intentioned surgeons have assumed for a long time now.
We really need to redefine what “obvious” means in medicine.
For a great plain language overview of the trouble with meniscectomy, see The Right to Know That an Operation Is ‘Next to Useless’.
I am a science writer, former massage therapist, and I was the assistant editor at ScienceBasedMedicine.org for several years. I have had my share of injuries and pain challenges as a runner and ultimate player. My wife and I live in downtown Vancouver, Canada. See my full bio and qualifications, or my blog, Writerly. You might run into me on Facebook or Twitter.
Most of the knee pain information on this website is about patellofemoral syndrome and iliotibial band syndrome, the two most common runner’s knee conditions, typically causing pain on the front and side of the knee respectively (learn more about the difference). Arthritis is not my usual subject matter, although I do keep tabs on it (particularly because of the way it is routinely confused with arthritis).
— Added new section about the trouble with meniscectomy.
— Added citations to Louw and Harris about ineffective surgeries in general.
— Added more scientific context, related citations, and expert perspective.
In this landmark and fascinating study, people with osteoarthritis improved equally well regardless of whether they received a real surgical procedure or a sham, which is a particularly striking example of the placebo effect and implies that belief can have an effect even on a “mechanical” knee problem. From the abstract: “In this controlled trial involving patients with osteoarthritis of the knee, the outcomes after arthroscopic lavage or arthroscopic debridement were no better than those after a placebo procedure.”
In 2008, these findings were fully supported by a Cochrane Collaboration review (Laupattarakasem) which concluded that “there is ‘gold’ level evidence that arthoscopic debridement has no benefit,” and by New England Journal of Medicine (Kirkley) which reported that “surgery for osteoarthritis of the knee provides no additional benefit to optimized physical and medical therapy.”
This study inspired more comparisons of orthopedic surgeries to shams. By 2016, at least four more popular surgeries have been shown to have no benefit (Louw 2016).BACK TO TEXT