Background: Sham control randomized controlled trials (RCT) are studies in which the control group includes invasive placebo procedure without the perceived active component of surgery. The sham group does not include the actual intervention but aims to mimic its invasive nature. There has been much ethical and methodological debate regarding the necessity and ethics of such studies. Methods: Pairing of RCT studies with the same active treatment but different control groups, RCT's with sham control and RCT's with conservative control groups was performed. The final conclusion from each study was recorded and evaluated. Results: Ten surgical interventions in sixty-eight studies that met inclusion criteria where evaluated. 32(47.05%) sham and 36(52.95%) conservative control RCTs. In 4 out of 10(40%) surgical intervention sham control RCT had different treatment recommendations than conservatives RCT's. In subjective patient reported outcome scores the placebo effect was measured to be 31% of overall treatment effect (p value=0.029). No major complication was recorded in the sham control group. The minor complications rate difference between sham and conservative control group was 0.03 per patient., Meaning that for every 33 patients in the sham group one additional minor complication is noted in the sham group compared to the conservative group. Conclusion: Sham control RCTs are effective and safe and have a role in evaluating the efficacy of new surgical treatments. The placebo effect in surgical subjective measured outcome is 31%, comparable to previous reports in the literature.
