Playing knee games
Just how strong is the placebo effect?
When a subject in a study has a response to a treatment he believes he has received (but in fact has not), we see just how easy it is for the mind to control our perceptions. This is the placebo effect. And now we know that when it comes to surgery it can be especially strong.
Last week I told you about the big news in the health world: the controversial halt of a major hormone replacement therapy study. But while that report was getting all the attention, another report quietly brought a surprising and important warning about a popular surgical treatment.
And it also gave us an intriguing look at how the mind can be convinced that nothing is something.
Unfortunately, treatments for osteoarthritis are somewhat limited. Patients with the disease are advised to avoid undue stress to affected joints. Supplements of glucosamine and chondroitin sulfate (more on this in a moment) can sometimes be effective. But in the last decade more and more patients who experience inflamed knee joints have resorted to arthroscopic surgery. Every year, well over half a million of these procedures are performed in which a small camera is inserted into the knee joint along with special surgical instruments.
For many doctors, however, the effectiveness of this surgery has been suspect for quite awhile. And now their suspicions have been confirmed in a surprising way with a study from the Houston Veterans Affairs Medical Center and Baylor College of Medicine.
Three types of surgery were performed on 180 participants: arthroscopic lavage (a fluid injection flushes irritating material out of the knee joint); arthroscopic dbridement (lavage plus a smoothing of rough areas of the joint); and placebo – which required a little bit of theater.
When each of the subjects arrived for the operation, the surgeons opened a sealed envelope that contained instructions on which of the three procedures they would employ. Those who were picked for lavage and debridement procedures received local anesthesia. The subjects who were designated as placebo, however, were given a general anesthesia so they would not be awake and able to observe that their surgery was not authentic.
For the placebo surgeries, the doctors made incisions in the subjects’ knees to simulate arthroscopic cuts. And this is where the surgery became more theatrical than medical. On the chance that the patient might experience the surgery on a subconscious level, the head surgeon asked for instruments and pretended to operate on the knee while another doctor sloshed water to create the sound of the knee being flushed.
Not to mention expensive. Medicare and insurance companies underwrite these operations to the tune of more than $1 billion every year. I would assume it’s a foregone conclusion that arthroscopic knee operations to treat osteoarthritis will lose their insurance coverage as a result of this study.
This was disheartening news for many surgeons who specialize in this procedure. Imagine finding out that your work is now regarded as little more than a parlor trick. And it’s an economic blow as well. As one doctor commented, this particular surgery constitutes something of an industry for certain orthopedic surgeons.
But I need to add one strong word of caution here. In an e-Alert I sent you last May (“When Treatments Collide” 5/7/02), I told you that osteoarthritis patients should avoid using chondroitin sulfate if they have prostate cancer or if their prostate specific antigen (PSA) levels are high. Recent reports have shown that chondroitin sulfate can cause prostate cancer cells to grow and spread to other sites. This is not true of glucosamine, which can be safely used by prostate cancer patients.
As someone who shares the pain of bad knees, I’m always looking for new options. When I find them, you’ll be the first to know. In the meantime, if you’re considering arthroscopic knee surgery to treat osteoarthritis, reconsider. It will do more for the surgeon’s wallet than it will do for your joint.
To Your Good Health,
Jenny Thompson
Health Sciences Institute
Sources:
“A Controlled Trial of Arthroscopic Surgery for Osteoarthritis of the Knee” The New England Journal of Medicine, 347:81-88, #2
“A Knee Surgery for Arthritis Is Called Sham” New York Times, 7/11/02
Copyright 1997-2002 by Institute of Health Sciences, L.L.C.
