What if the surgery that fixed your knee did no better than fake surgery? EconTalk host Russ Roberts speaks with Dr. John Mandrola about a striking clinical trial in which patients who received sham knee surgery (a real incision, but no actual repair) did as well or better than those who had the actual procedure--one performed 700,000 times annually in the U.S. The conversation ranges from the power of placebo and nocebo effects (how expectation of harm can cause real suffering) to the broader philosophy of "medical conservatism"--the idea that humility, watchful waiting, and honest counsel often serve patients better than the knife. Mandrola argues that financial incentives, professional identity, and language itself ("bone-on-bone," "the widowmaker") conspire to push patients toward interventions that can do more harm than good.