In 2002, researchers at the Houston VA Medical Center and at Baylor College of Medicine found that a common type of knee surgery known as debridement to be no more beneficial than a placebo surgery.
"I was initially very surprised," Dr. Bruce Moseley, an orthopedics professor at Baylor who performed both the real and placebo surgeries in the study, told United Press International. "I could not imagine anybody suggesting that anything we do in surgery would be beneficial from a placebo effect. I associate placebo effect with pills."
Throughout a two year follow-up, the 180 patients in the study were unaware whether they had received the "real" or placebo surgery. Patients who received actual surgical treatments did not report less pain or exhibit better functioning of their knees compared to the placebo group. In fact, periodically during the follow-up, the placebo group reported a better outcome compared to the patients who underwent debridement.