Many Orthopedic Surgeries Don’t Work Better Than Placebo
Research on “sham” surgery shows that effects may be more psychological than physical
Unlike drugs, orthopedic surgeries can be sold to the public before they undergo rigorous testing to ensure they are safe and effective. Thus, millions of surgeries for knee, shoulder, and back pain have been done without studies to confirm they actually work. Recently, research has found that many popular surgeries (but not all) work no better than a placebo. And yet these surgeries are still done at the rate of hundreds of thousands per year. This is something you should know if you are considering surgery, or in the business of treating chronic pain.
Knee Surgery
Osteoarthritis of the knee is common but does not necessarily result in pain — many people have arthritis and no pain at all. But surgery to correct arthritis is popular, numbering as many as a half million per year in the U.S. alone. (1)
About 15 years ago, two of the most common procedures were debridement (removal of damaged cartilage or bone) or lavage (irrigation with saline solution). The goal of either surgery was removal of rough fragments of cartilage that may be irritating the joint. The surgery’s benefits were known to be not so impressive, so people started to wonder whether they were caused by placebo, or could be achieved with less invasive treatment.
To answer these questions, a study was done using a “sham” surgery: one group of patients received real knee surgery, and the other a fake, which involved just an incision on the skin. At several times over the course of a couple years, the two groups reported their levels of knee pain and function. The result? The sham group did just as well as the surgical group at all points in time. (2) This strongly suggests the surgery worked by changing psychology, not structure.