A few weeks ago I listened to an excellent Hidden Brain Podcast about placebos and not just the sugar pill kind of placebo. This podcast recounted an amazing clinical trial done way back in 2002 which put the very common procedure of arthroscopic knee surgery for osteoarthritis to the test. I will summarize that study here but I really encourage everyone to listen to the podcast. There are also some links to the original paper published in the New England Journal of Medicine.
So here we go with my summary: 180 patients with osteoarthritis of the knee were randomly assigned to one of three groups. The assignments were controlled for severity of disease.
Group 1 : Routine arthroscopic surgery to wash out and clean up any irregularities in the knee joints
Group 2: The incision was made, the arthroscope was inserted and the knee joint washed out (lavaged) but nothing else was done.
Group 3: An incision was made but the arthroscope was never inserted.
The patients did not know which group they were in nor did their families or the nurses who cared for them after surgery. The surgeon and the operating team did not know which procedure the patient would have until the patient was on the OR table and anesthetized and the randomization envelope was opened. For groups 2 and 3, a video of standard knee surgery was played and the OR team sort of faked the movements of the surgery and the time in the OR was the same for all groups. One surgeon did all of the cases. Group 1 is the real operation, Group 2 is the lavage group and Group 3 is the sham procedure. Now some commentary on this study. These patients had honest to goodness osteoarthritis of the knee confirmed by history, exam and X-Rays. This was not a group of patients with ill defined and subjective complaints. These were patients with objective disease. .
Follow up at two years showed no statistically significant difference in relief of symptoms as reported by the patients or function as measured by walking and climbing stairs between Group 1 (real surgery), Group 2 (lavage only) and Group 3 (sham surgery). Think about this for a moment……….An arthroscopic clean out of the knee joint had no more effect than a superficial skin incision.
I remember the reaction to this study when it was published. At that time I did a lot of my surgery at Seattle Surgery Center and I had the opportunity to hob nob with a lot of orthopedic surgeons. The ortho bros often teased me for all the unnecessary surgery I do. Yeah, it’s true. The vast majority of cases I do are unnecessary. This study allowed me to tease them about their “scoping for dollars” practices. I think a lot of scoping for dollars still goes on (mostly because patients request it) but maybe a little less since this paper smacked everyone upside the head.
Isn’t it just amazing what the human mind can do? It can convince the body that the sugar pill was the real thing or even that the sham surgery was the real thing!
Thanks for reading and really you should listen to this podcast! And as usual, I would be honored if you followed me on Instagram @sowdermd and @breastimplantsanity. Dr. Lisa Lynn Sowder