Arthroscopic Knee Surgery No Better Than Placebo, NEJM Study Finds

Arthroscopic knee surgery results in no more improvement than placebo surgery, raising questions about whether the $5,000 procedure should be performed at all, according to a new study, the Houston Chronicle reports (Hopper, Houston Chronicle, 7/11). About 650,000 people annually have the surgery, which is thought to treat arthritic knees, at a total cost of about $3 billion, according to the Wall Street Journal (Winslow, Wall Street Journal, 7/11). In the study, published in today's issue of the New England Journal of Medicine, Dr. Bruce Moseley, an orthopedic surgeon at Baylor College of Medicine and the Houston Veterans Affairs Medical Center, enrolled 180 men with osteoarthritis and divided them evenly into three groups that would receive one of two types of arthroscopic surgery or placebo surgery. The participants were told that they might not receive surgical treatment and that they would not know which group they were in until two years later. Actual surgery patients underwent normal procedures, while the patients in the placebo group were given intravenous tranquilizers to make them sleep and received "three small incisions" in their knee to mimic the real procedure. During placebo procedures, staff also mimicked the sounds of the surgery, asked for instruments and played a video on overhead monitors of a previously performed surgery.

All three groups of patients were monitored for two years following the operations. The study found that between 35% and 40% of all patients reported "less pain" in their knee at the end of the trial, and patients who received placebo surgery reportedly "felt better" after two years. However, no participants in any of the groups showed "actual improvement" when timed as they ran or walked 100 feet and climbed stairs. In addition, researchers found that patients in the placebo group were not more likely to guess that they had been in the placebo group. The study "clearly shows a very strong placebo effect, particularly for something as significant in the patient's mind as surgery," Moseley said (Houston Chronicle, 7/11). Nelda Wray, a health services researcher at the Houston VA hospital, said the study "makes us question ... the risks that we're putting patients through and the dollars that we're spending" on arthroscopic knee procedures (Okie, Washington Post, 7/11). She added that the study "suggests that patients and doctors consider other remedies ... such as anti-inflammatory medicines, exercise, weight loss and total knee replacement" (Wall Street Journal, 7/11). Secretary of Veterans Affairs Anthony Principi said that the study would "change the practice of orthopedic medicine in the United States," but VA officials did not indicate whether the department would stop paying for such surgeries (Kolata, New York Times, 7/11).

In an editorial accompanying the study, Sam Horng and Dr. Franklin Miller of NIH wrote that while doctors assume that patients in clinical research should not be put at risk "if they cannot benefit," studies are not meant to help their participants but should help future patients. The knee study "exemplifies the ethically justified use of placebo surgery" because it met three criteria: it did not place patients at undue risk; the benefits of learning whether the surgery works were worth any potential risk to patients; and patients gave informed consent (New York Times, 7/11). Moseley said that of 324 patients invited to participate in the trial, 44% declined, a refusal rate that "let investigators know the consent procedures were thorough" (Houston Chronicle, 7/11).