HOUSTON, July 10 (UPI) -- For individuals suffering from osteoarthritis in their knees, a common type of knee surgery has been found to be no more beneficial than a placebo, a new study revealed Wednesday.
Researchers at the Houston VA Medical Center and at Baylor College of Medicine came to this surprising conclusion after comparing various knee treatments to placebo surgery on 180 patients with knee pain.
The patients were randomly divided into three groups. One group underwent debridement, in which the damaged or loose cartilage is the knee is surgically removed by an arthroscope, a pencil-thin tube that allows doctors to see inside the knee. The second group received arthoscopic lavage, which flushes out the bad cartilage from the healthier tissue. A third group underwent a placebo surgery. They were sedated by medication while surgeons simulated arthroscopic surgery on their knees by making small incisions on the leg, but not removing any tissue.
During a two-year follow-up, researchers found no differences among the three groups. All patients reported improvement in their symptoms of pain and ability to use their knees. Throughout the two years, patients were unaware whether they had received the "real" or placebo surgery.
However, patients who received actual surgical treatments did not report less pain or better functioning of their knees compared to the placebo group. In fact, periodically during the follow-up, the placebo group reported a better outcome compared to the patients who underwent debridement.
"I was initially very surprised," Dr. Bruce Moseley, an orthopedics professor at Baylor who performed both the real and placebo surgeries in the study, told United Press International. "I could not imagine anybody suggesting that anything we do in surgery would be beneficial from a placebo effect. I associate placebo effect with pills."
When asked why patients responded so strongly to the placebo surgery, Moseley said they believed they had been helped by surgery, which seemed to make a difference in their perception.
"In my simple surgeon's explanation of this, the magnitude of placebo effect is directly proportional to the patient's perceived intervention," Moseley explained.
Arthroscopic surgery has been used to treat knee problems since the 1970s, Moseley said, but when it came to treating osteoarthritis of the knee, "there was a section of the orthopedic community that remained skeptical."
Dr. Kevin Stone, an orthopedic surgeon at the Stone Clinic and founder and director of the Stone Foundation for Sports Medicine and Arthritis Research in San Francisco, said arthroscopic lavage combined with debridement still has a lot to offer knee patients with osteoarthritis.
"I think there is a beneficial effect for surgery alone if it's done in accomplished hands and with the right patient preparation, but without that in place it can be more harm than good," Stone told UPI.
However, Stone said it is "absolutely" possible patients can achieve a placebo effect from a fake surgery. "Because when patients get prepared for surgery ... they feel invested both financially, emotionally and physically in the outcome," which in the end, can help them feel better.
Osteoarthritis of the knee is common among athletes and sports enthusiasts, but can also occur among sedentary people who have suffered strain to their knees. The condition occurs when the cartilage and bone around the knee joint become damaged from wear and tear.
The findings are published in the July 11 issue of The New England Journal of Medicine.
(Reported by Katrina Woznicki, UPI Science News, in Washington.)
