Monday, Jul. 22, 2002

What the Knees Really Need

By Janice M. Horowitz

Of all the moving parts in the body, few take as much abuse as the knee. With the momentum of each step, your knee joint absorbs three times your body weight. Straighten up from a deep squat, and the pressure on the joint can reach nine times your weight. Throw in a few falls or sharp blows, and that knee of yours will eventually wear out--and, in due time, develop painful osteoarthritis. That's why last week's news about a popular form of surgery to relieve pain from arthritis of the knee was so devastating.

The operation is called arthroscopic knee surgery, and more than a quarter-million Americans were getting it each year. Doctors would make three small incisions in the knee, insert a tiny scope, flush debris out of the area with water and sometimes shave away rough surfaces around the joint to help the tendons and ligaments glide more smoothly. Part of the appeal of the surgery was that it was minimally invasive; most patients walked away requiring little or no recovery time.

The only problem is that it didn't do any good. How do we know? Doctors ran it through a rarely used but devastatingly effective test: sham surgery. They randomly assigned some patients to undergo the surgery while other patients were wheeled into the operating room, sedated, given superficial incisions (accompanied by the commands and operating-room noises they would hear if the real surgery were taking place), patched up and sent home.

The result? According to a report published in the New England Journal of Medicine, the fake surgery worked just as well as the real one. Two years later, 35% of the patients said they felt less pain and were better able to get around--whether they were operated on or not. In some instances, sham patients outperformed real ones. In other words, the surgery worked no better than--and sometimes not as well as--a placebo.

"This casts grave doubt on the procedure," says Nelda Wray, chief of general medicine at Veterans Affairs Medical Center in Houston and one of the researchers on the study. "It's putting people at risk for no benefit." It's also expensive: at $5,000 a pop, the operation was costing the U.S. more than $1 billion a year.

So what's left for the 6% of Americans 30 or older and 12% of those 65 or older who suffer from osteoarthritis of the knee? Plenty. If you are overweight, the first step is obvious. If you lose just 5 lbs., that's 15 lbs. less pressure on your knees. Exercises can also make a difference. Strengthening the quadriceps around the knee with leg lifts will relieve some of the pressure on the joints. If you play sports or engage in other vigorous activities, doctors recommend a heating pad before and an ice pack afterward. For pain relief, over-the-counter anti-inflammatories, like aspirin and ibuprofen, can help.

If all else fails, there's one last surgical approach: total knee replacement. It's a major operation that involves removing the worn-away knee cap, replacing it with a plastic one and resurfacing the adjacent bones with plastic and metal veneer. It requires months of postsurgical physical therapy, but doctors report that the operation is up to 90% effective. Or at least they think it is.

For more info, go to www.aaos.org or e-mail jmhtime@aol.com