Sham surgery: an ethical analysis.

Surgical clinical trials have seldom used a "sham" or placebo surgical procedure as a control, owing to ethical concerns. Recently, several ethical commentators have argued that sham surgery is either inherently or presumptively unethical. In this article I contend that these arguments are mistaken, and that there are no sound ethical reasons for an absolute prohibition of sham surgery in clinical trials. Reflecting on three cases of sham surgery, especially on the recently reported results of a sham-controlled trial of arthroscopic surgery for arthritis of the knee, I present an ethical analysis that focuses on the methodological rationale for use of sham surgery, risk-benefit assessment, and informed consent.