Read and respected by more doctors of chiropractic than any other professional
publication in the world.
A publication of the World Chiropractic Alliance
by Dr. Christopher Kent
Many scientists and clinicians consider the placebo-controlled trial
the "gold standard" for evidence-based practice. Coulter 
notes that according to The Office of Technology Assessment,
"Objections are rarely if ever raised to the principles of controlled
experimentation on which RCTs are based." Others have stated that
placebo-controlled trials are needed to provide data on effectiveness of
active treatment. 
Interestingly, surgical procedures are often exempt from such scrutiny.
Ethical considerations are considered barriers to the use of
placebo-controlled investigations for surgical procedures. [3, 4]
Interestingly, there have been five studies where placebo surgery was used
as a control. The placebo group generally did as well or better than the
group receiving the real operation.
In 1939, a surgeon named Feischi developed a surgical procedure for
angina pectoris. He reasoned that if the blood flow to the myocardium
could be increased, the symptoms of angina would diminish. It was felt
that ligating the internal mammary artery would increase myocardial blood
flow. The clinical results were favorable, and the operation became
popular, with three-quarters of patients reporting improvement or
elimination of symptoms. 
Twenty years later, The New England Journal of Medicine (NEJM)
published the results of a placebo-controlled trial of internal mammary
artery ligation.  Of 17 patients, eight got the actual operation. The
other nine were anesthetized and got incisions, but nothing else. The fake
operations worked as well as the real thing. As a result, internal mammary
artery ligation surgery was soon abandoned.
The next wave of placebo surgery involved the human brain. Fetal pig
nerve cells were implanted into the brains of 10 patients with Parkinson's
disease. Eight patients had holes drilled into their heads, but received
no implants. It was reported that "no significant improvement
resulted from implanting the fetal cells of pigs into patient brains when
compared with subjects who received placebo surgery." 
A second study, involving the implantation of stem cells from aborted
human fetuses into the brains of patients with Parkinson's disease, was
reported in NEJM.  Twenty of 40 patients received sham surgery,
and 20 got the real thing. Holes were drilled into the skulls of the
patients receiving sham surgery. Thankfully, the authors noted that
"the dura was not penetrated." Some younger subjects were
claimed to experience some benefit. Older subjects receiving the stem
cells reported a worsening of their condition.
The latest study was a controlled trial of arthroscopic surgery for
osteoarthritis of the knee. A total of 180 patients with osteoarthritis of
the knee were randomly assigned to receive arthroscopic debridement,
arthroscopic lavage, or placebo surgery. Pain and function were assessed
over a 24-month period. The result? "At no point did either of the
intervention groups report less pain or better function than the placebo
group."  This investigation followed a smaller pilot study with
similar results. 
The notion of being subjected to unnecessary surgery is horrifying
enough. Yet, that is only part of the story. According to one report,
arthroscopic surgery for osteoarthritis of the knee is done on at least
225,000 Americans each year, termed "a sham" by Dr. Baruch
Brody, an ethicist at Baylor College of Medicine.  The cost of this
intervention is estimated at $3.25 billion per year. 
The power of the placebo cannot be denied -- mobilization of the
inherent recuperative powers of the body. With placebo surgery, we must
ask, "At what cost, and at what risk?" Keep this in mind the
next time someone tells you they have to have surgery.
Where's the science? Or are anecdotes and conjecture good enough?
The controlled clinical trial. An analysis.
Washington (DC): Center for Empirical Medicine. Project Cure; 1991.
Placebo controlled trials are needed to provide data on
effectiveness of active treatment (editorial).
Horng S, Miller FG:
Is placebo surgery unethical? N
Engl J Med 2002;347(2):137.
I need a placebo like I need a hole in the head.
J Law Med Ethics 2002;30(1):69.
Sham surgery returns as a research tool.
New York Times. 4/25/99.
Cobb LA, Thomas GI, Dillard DH, et al:
An evaluation of internal mammary artery ligation by a double-blind technic.
Engl J Med 1959;260:1115.
Placebo surgery gains wider acceptance.
Freed CR, Greene PE, Breeze RE, et al:
Transplantation of embryonic dopamine neurons for severe Parkinson's disease.
J Med 2001;344(10):710.
Moseley JB, O'Malley K, Peterson NJ. Et al:
A controlled trial of arthroscopic surgery for osteoarthritis of the knee.
N Engl J Med 2002;347(2):81.
Moseley JB, Wray NP, Kuykendall D, et al:
Arthroscopic treatment of osteoarthritis of the knee: a prospective, randomized, placebo-controlled trial. Results of a pilot study.
Am J Sports Med 1996;24(1):28.
A knee surgery for arthritis is called a sham.
The New York Times. 7/11/02.
(Dr. Christopher Kent, president of the Council on Chiropractic
Practice, is a 1973 graduate of Palmer College of Chiropractic. The WCA's
"Chiropractic Researcher of the Year" in 1994, and recipient of
that honor from the ICA in 1991, he was also named ICA "Chiropractor
of the Year" in 1998. He is director of research and a co-founder of
Chiropractic Leadership Alliance. With Dr. Patrick Gentempo, Jr., Dr. Kent
produces a monthly audio series, "On Purpose," covering current
events in science, politics and philosophy of vital interest to the
Copyright 1986-2002 The Chiropractic Journal
Return to PROBLEMS WITH PLACEBOS