Sham surgery
Sham surgery (placebo surgery) is a faked surgical intervention that omits the step thought to be therapeutically necessary.
In clinical trials of surgical interventions, sham surgery is an important scientific control. This is because it isolates the specific effects of the treatment as opposed to the incidental effects caused by anesthesia, the incisional trauma, pre- and postoperative care, and the patient's perception of having had a regular operation. Thus sham surgery serves an analogous purpose to placebo drugs, neutralizing biases such as the placebo effect.
Human research
The placebo-controlled trial is the gold standard of medical research. Therefore, when testing results of a surgical procedure, sham surgery serves as the intervention in the control population. However, the use of sham surgery in human research is controversial, as it places ethical and research standards into conflict. While sham surgery has the potential to harm the subject, research designs without sham surgery are scientifically less rigorous. Proponents argue that surgical interventions need to be tested as critically as pharmaceutical interventions. One partial solution is that when a clinical trial is over, those people who received sham surgery may be offered a second surgery including the actual treatment. Because of the ethical concerns, sham-controlled studies are rarely performed in humans.