When is surgery a placebo?

Points to consider

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Skeptics often claim that acupuncture is just a placebo.1-4 However, these individuals typically have neither closely examined the methodology for neuroanatomic overlap between verum and placebo “points,” which makes outcomes between groups similar, nor have they assessed the tissue-deforming effects of so-called “sham” needling because they simply assume that sham needles are inert. They aren’t.

On the other hand, how many have dared to question whether some surgeries are no better than placebo? How many students in professional medical or veterinary schools feel empowered to ask their surgery professors for evidence that the “gold standard” approaches they are learning have been sufficiently tested and proven valuable?

Safety and Health

With medical errors ranking as the third-leading cause of human death in the United States for human patients,5 it behooves medical practitioners to make treatment decisions that improve patient safety and health based on science and evidence. Surgery is no exception.

As stated by the authors of a systematic review concerning placebo controls in surgical trials, “Without well-designed placebo-controlled trials of surgery, ineffective treatment may continue unchallenged.”6

The authors also noted: “The increase in the applications for surgical procedures has been driven by a greater involvement of technology in surgical procedures. Such technological advances have made many interventions less invasive, more likely to be endoscopic and less resembling typical open surgery, such as laparotomy. However, these new procedures are often introduced into surgical practice without any formal evaluation of safety and efficacy, such as using randomized clinical trials. This is because, unlike drug products, such verification is currently not mandated by regulatory authorities.”7

The authors note as well that, “Placebo-controlled trials in surgery are as important as they are in medicine, and they are justified in the same way. They are a powerful, feasible way of showing the efficacy of surgical procedures. They are necessary to protect the welfare of present and future patients as well as to conduct proper cost effectiveness analyses. … Without such studies ineffective treatment may continue unchallenged.”8

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Influential Study

One of the seminal studies that brought the notion of surgical placebos to light appeared in the New England Journal of Medicine in 2002.9 At that time, over 650,000 procedures involving arthroscopic lavage or debridement were being performed annually at a cost of what a veterinary client might pay nowadays for a stifle surgery such as tibial plateau leveling osteotomy (TPLO), i.e., $5,000.

While over one-third of dogs experience chronic pain on stifle palpation after surgical repair of cruciate disease,10 about half of the people undergoing arthroscopy continued to have pain. Why the other half responded favorably to the intervention was unclear at the time.

Debridement is not without risk; it involves removal of damaged cartilage or bone. Patients could experience one or more of the following as a result: hemorrhage; thrombus or embolus formation; nerve damage; injury to the cartilage, menisci or ligaments of the knee; joint infection; and prolonged pain, stiffness or dysfunction of the joint. As such, if the procedure proved to be ineffective (not to mention the added risk of anesthesia), why do it?

How Study Was Done

In order to investigate its value, researchers set out to compare the effectiveness of debridement, lavage and placebo in 180 patients.

Those in the debridement group underwent the following: diagnostic arthroscopy, lavage with at least 10 liters of fluid, shaving of rough articular cartilage, removal of loose debris, trimming of torn and degenerated meniscal fragments, and smoothing of any remaining meniscus.

Patients in the lavage group experienced flushing of the joint only but no instrument-assisted removal of tissue. Unstable tears of menisci deemed mechanically important were addressed for lavage subjects as they were in the debridement group because researchers felt that it would be inappropriate to leave a problematic meniscal tear untreated.

Subjects in the placebo group were prepped and draped just like the others. The surgeon made three 1-centimeter incisions and simulated the surgical approach as if arthroscopy was being performed. Saline was splashed onto the site to simulate the sounds of lavage, but no instrument entered the arthroscopy portals.

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Study personnel in charge of outcome assessments were unaware of the treatment group assignments. They collected data at regular intervals following the procedure up until 24 months. As the researchers reported, “Patients in the placebo group were no more likely than patients in the other two groups to guess that they had undergone a placebo procedure.”

In their ongoing monitoring, researchers asked about pain from the arthritis, generalized pain and several aspects of physical function.

Surprising Conclusions

What the researchers found was shocking. They wrote: “This study provides strong evidence that arthroscopic lavage with or without debridement is not better than and appears to be equivalent to a placebo procedure in improving knee pain and self-reported function. Indeed, at some points during follow-up, objective function was significantly worse in the debridement group than in the placebo group.”

They continued: “Arthroscopy is the most commonly performed type of orthopedic surgery, and the knee is by far the most common joint on which it is performed. Numerous uncontrolled, retrospective case series have reported substantial pain relief after arthroscopic lavage or arthroscopic debridement for osteoarthritis of the knee.”

Indeed, if this group had not included a placebo group, one might have speculated that lavage might be “doing something” by eliminating painful debris and inflammatory mediators. Researchers also had addressed meniscal damage in both the lavage and debridement groups. However, by including a placebo group that had no manipulation of their menisci, the authors determined that the lack of difference between all outcomes across all three groups “suggests that the improvement is not due to any intrinsic efficacy of the procedures.”

In a 1998 New England Journal of Medicine editorial, Angell and Kassirer exhorted: “It is time for the scientific community to stop giving alternative medicine a free ride. There cannot be two kinds of medicine—conventional and alternative. There is only medicine that has been adequately tested and medicine that has not, medicine that works and medicine that may or may not work.

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“Once a treatment has been tested rigorously,” they continued, “it no longer matters whether it was considered alternative at the outset. If it is found to be reasonably safe and effective, it will be accepted. But assertions, speculation and testimonials do not substitute for evidence. Alternative treatments should be subjected to scientific testing no less rigorous than that required for conventional treatments.”

Substitute the word “surgery” for “alternative medicine.” The time has come to ask, “Why are we giving surgery a free ride?”


  1. Lin JH and Panzer R. “Use of Chinese Herbal Medicine in Veterinary Science:  History and Perspectives.” Rev Sci Tech Off Int Epiz. 1994;13(2):425-432.
  2. Xie H and Preast V (eds.). “Xie’s Chinese Veterinary Herbology.” Ames, IA: Wiley-Blackwell, 2010, p. 1.
  3. Liu CM, Holyoak GR, and Lin CT. “Acupuncture Combined With Chinese Herbs for the Treatment in Hemivertebral French Bulldogs With Emergent Paraparesis.”  Journal of Traditional and Complementary Medicine.  2016;6:409-412.
  4. Robinson N. “Why the Standards of Care for Spinal Cord Injuries Are Changing.” Veterinary Practice News.  May 16, 2016. Accessed at on 10-31-16.
  5. Robinson NG. “Laser Therapy May Work on TL IVDD.” Veterinary Practice News. March 11, 2010. Accessed at on 10-31-16.
  6. Robinson N. “Got a Spinal Cord Injury? Get Acupuncture!” Veterinary Practice News. Nov. 2, 2015.  Accessed at on 10-31-16.
  7. WebMD. “Nux Vomica.” Accessed at on 10-31-16.
  8. U.S. FDA website. FDA Poisonous Plant Database. “Strychnine Poisoning From the Use of a Cambodian Traditional Remedy.” Accessed at on 10-31-16.
  9. WebMD. “Nux Vomica.” Accessed at on 10-31-16.
  10. Chan TY. “Aconite poisoning.” Clin Toxicol. 2009;47(4):279-285.

Dr. Narda Robinson is president and CEO of CuraCore Integrative Medicine and Education Center in Fort Collins, Colo. Columnists’ opinions do not necessarily reflect those of Veterinary Practice News. 

Originally published in the November 2016 issue of Veterinary Practice News. Did you enjoy this article? Then subscribe today! 

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