The placebo effect is based on the expectations of the patient regarding the effectiveness of the treatment. The high levels of stress and rituals involved with surgery can lead to a strong placebo effect. However, the ethical principles of performing sham surgery to measure any placebo effect have been questioned, and sham-controlled surgical trials are rarely conducted. While there are a number of ethical principles that must be considered to justify the implementation of a sham-controlled surgical clinical trial, four areas deserve particular attention: equipoise, risk minimization, informed consent, and deception. Particularly in orthopaedics, where equipoise is common, sham-controlled trials may be important to ensure that inferior or ineffective treatments do not become standard practice.